LIBRARY 
 
 OF THE 
 
 UNIVERSITY OF CALIFORNIA. 
 
 Class 
 
GENERAL SPECIFICATIONS FOR 
 STRUCTURAL WORK OF. 
 BUILDINGS. 
 
 BY 
 
 C C. SCHNEIDER, M. Am. Soc. C E. 
 
 NEW YORK: 
 
 THK ENGINEERING NEWS PUBLISHING COMPANY. 
 1910. 
 
GENERAL SPECIFICATIONS FOR 
 
 STRUCTURAL WORK OF 
 
 BUILDINGS. 
 
 BY 
 
 C. C. SCHNEIDER, M. Am. Soc. c. E. 
 
 Of THE 
 
 UNIVERSITY 
 
 OF 
 
 LUFOR] 
 
^ 
 
 ( 
 
 c 
 
 COPYRIGHTED 1910 BY 
 C. C. SCHNEIDER. 
 
OF THE 
 
 UNIVERSITY 
 
 OF 
 4 L I FOR] 
 
 PREFACE. 
 
 This edition of the General Specifications for Structural Work of 
 Buildings is a reprint from the one published in Transactions of the 
 American Society of Civil Engineers, Vol. LIV, page 490 (1905), re- 
 vised to date. It contains additional tables and other useful informa- 
 tion, also specifications for concrete and reinforced concrete for build- 
 ing construction. 
 
 As reinforced concrete construction has lately come into extended 
 use for building work, the writer thought it expedient to include a set 
 of regulations covering its essential requirements, based on what he 
 considers safe practice. 
 
 In preparing specifications for reinforced concrete, the writer has 
 been guided by those already in existence, the most prominent of 
 which are the regulations of the French, Prussian, Austrian and Swiss 
 Governments, the Association of German Architects and Engineers, 
 the German Concrete Association, and those proposed by a joint com- 
 mittee of the British Architectural and Building Associations and the 
 Government Bureaus and the recommendations of the Special Com- 
 mittee on Concrete and Reinforced Concrete of the American Society 
 of Civil Engineers, with such modifications as have been suggested 
 by experience and the lessons taught by failures. 
 
 For that part of the specifications covering aggregates, preparation 
 and placing of concrete and mortar, the recommendations of the 
 Special Committee on Concrete and Reinforced Concrete of the Ameri- 
 can Society of Civil Engineers have been adopted as representing the 
 best modern practice. 
 
 C. C. SCHNEIDER. 
 
 PHILADELPHIA, PA., May, 1910. 
 
 206530 
 
CONTENTS. 
 
 GENERAL SPECIFICATIONS FOR STRUCTURAL 
 WORK OF BUILDINGS. 
 
 DESIGN. 
 
 LOADS 7-9 
 
 UNIT STRESSES AND PROPORTION OF PARTS 9-12 
 
 Substructure, Unit Stresses 9, 10 
 
 Masonry Pillars and Walls 10-12 
 
 Steel Superstructure, Unit Stresses 12-14 
 
 Cast Iron 14 
 
 Timber 14 
 
 Details of Steel Construction 14-18 
 
 MATEEIAL AND WOEKMANSHIP. 
 
 MATERIAL 18-21 
 
 Rolled Steel 18-21 
 
 Steel Castings 19, 20 
 
 WORKMANSHIP 21-24 
 
 Shopwork 21-24 
 
 Painting 24 
 
 Inspection and Tests 24, 25 
 
 Full-sized Tests 25 
 
 CONCRETE AND REINFORCED CONCRETE. 
 
 PROPER USE OF CONCRETE 27 
 
 IMPROPER USE OF CONCRETE 27-29 
 
 RESPONSIBILITY AND SUPERVISION 29, 30 
 
 SPECIFICATIONS FOR PLAIN AND REINFORCED CONCRETE CON- 
 STRUCTION 31-41 
 
 Design . ; 31-35 
 
 General Assumptions for Static Computations 32 
 
 External Forces 32 
 
 Internal Forces 32, 33 
 
 Working Stresses 33, 34 
 
 Details of Construction 35, 36 
 
 MATERIALS AND WORKMANSHIP 36 
 
 Aggregates 36, 37 
 
 Steel 37 
 
 Concrete 37-40 
 
 Inspection and Tests 40, 41 
 
 FORMULAS FOR APPROXIMATE COMPUTATIONS. . . 42-44 
 
APPENDIX. 
 CONSISTING OF THE FOLLOWING TABLES : 
 
 PAGE 
 
 1. Weights of Building Materials, etc 45 
 
 2. Weights of Merchandise, etc 45 
 
 3. Permissible Compressive Strain 46 
 
 4. Shearing and Bearing Value of Kivets , 47 
 
 5. Maximum Bending Moments on Pins 48 
 
 6. Thickness of Spruce and White Pine Plank for Floors 48 
 
 7. Standard Dimensions of Columns 49 
 
 8. Standard Beam Framing 50 
 
 Separators 50 
 
 Cast-Iron Washers 50 
 
 9. Standard Details 51 
 
 10. Plate Girders 52 
 
 11. Weights of Eoof Trusses 53 
 
 12. Dimensions of Typical Hand Cranes 53 
 
 13. Dimensions of Typical Electric Traveling Cranes 54 
 
 14. Abstracts from Building Laws 55-68 
 
 
GENERAL 
 
 SPECIFICATIONS FOR STRUCTURAL 
 WORK OF BUILDINGS. 
 
 DESIGN. 
 LOADS. 
 
 1. The "dead" load in all structures shall consist of the weight Dead Load, 
 of walls, floors, partitions, roofs and all other permanent construction 
 
 and fixtures. 
 
 2. In calculating the "dead" loads, the weights of the different 
 materials shall be assumed as given in Table 1. 
 
 3. The minimum weight of fire-proof floors to be assumed in de- 
 signing the floor system shall be 75 Ib. per sq. ft. For columns, the 
 actual weight of floors shall be used. 
 
 4. For office buildings, 10 Ib. per sq. ft. of floor area shall be 
 added to the dead load of the floor for movable partitions. 
 
 5. The following table gives the "live" load on floors, to be as- 
 sumed for different classes of buildings. These loads consist of: 
 
 a. A uniform load per square foot for floor area; 
 b. A concentrated load which shall be applied to any point 
 of the floor; 
 
 c. A uniform load per linear foot for girders. 
 The maximum result is to be used in calculations. 
 The specified concentrated loads shall also apply to the floor 
 construction between the beams for a length of 5 ft. 
 
 TABLE OF LIVE LOADS. 
 
 Live Load 
 on Floors. 
 
 Classes of buildings. 
 
 LIVE LOADS, IN POUNDS. 
 
 Distributed 
 load. 
 
 Concentrated 
 load. 
 
 Load per linear 
 foot of girder. 
 
 Dwellings, hotels, apartment-houses, dormi- 
 tories, hospitals. 
 
 40 
 50 
 
 60 
 
 80 
 
 I floor 100 
 C columns 50 
 
 80 
 300 
 from 120 up 
 " 300 u 
 
 ( 
 " 200 "J 
 
 2 000 
 5 000 
 
 5 000 
 
 5 000 
 
 j- 5 000 
 
 8 000 
 10 000 
 Special. 
 
 The actual t 
 gines, boilers, 
 shall be used, 1 
 less than 200 It 
 
 500 
 1 000 
 
 1 000 
 1 000 
 
 1 000 
 
 1 000 
 1 000 
 Special. 
 
 weights of en- 
 stacks, etc., 
 jut in no case 
 . per sq. ft. 
 
 Office buildings, upper stories 
 
 Schoolrooms, theater galleries, churches 
 
 Ground floors of office buildings, corridors 
 and stairs in public buildings 
 
 Assembly rooms, main floors of theaters, 
 ballrooms, gymnasia, or any room likely 
 to be used for drilling or dancing 
 
 Ordinary stores and light manufacturing, 
 stables and carriage-houses 
 
 Sidewalks in front of buildings. . 
 
 Warehouses and factories 
 
 Charging floors for foundries 
 
 Power-houses, for uncovered floors 
 
8 
 
 Crane Loads 
 and Impact. 
 
 Live Loads 
 on Flat 
 Roofs. 
 
 Wind 
 Pressure. 
 
 Live Loads 
 on Roofs. 
 
 Loads on 
 Ordinary 
 Roofs. 
 
 6. If heavy concentrations, like safes, armatures, or special ma- 
 chinery, are likely to occur on floors, provision should be made 
 for them. 
 
 7. For structures carrying traveling machinery, such as cranes, 
 conveyors, etc., 25% shall be added to the stresses resulting from 
 such live load, to provide for the effects of impact and vibrations. 
 (For crane loads, see Tables 12 and 13.) 
 
 8. Flat roofs of office buildings, hotels, apartment-houses, etc., 
 which can be loaded by crowds of people, shall be treated as floors, 
 and the same distributed live loads shall be used as specified for 
 hotels and dwelling-houses. 
 
 9. The wind pressure shall be assumed acting in any direction 
 horizontally : 
 
 First. At 20 Ib. per sq. ft. on the sides and ends of buildings 
 and on the actually exposed surface, or the vertical projection 
 of roofs; 
 
 Second. At 30 Ib. per sq. ft. on the total exposed surfaces 
 of all parts composing the metal framework. The framework 
 shall be considered an independent structure, without walls, par- 
 titions or floors. 
 
 10. Roofs shall be proportioned to carry in addition to their own 
 weight the following live loads: 
 
 a. A snow load, per horizontal square foot of roof, of 25 
 Ib. for all slopes up to 20; this load to be reduced 1 Ib. for 
 every degree of increase in the slope up to 45, above which no 
 snow load is considered. 
 
 b. A wind load as specified in paragraph 9. 
 
 The possibility of a partial snow load has to be considered. 
 
 The above loads given for snow are the minimum values for locali- 
 ties where snow is likely to occur. In severe climates these snow 
 loads should be increased in accordance with the actual conditions 
 existing in those localities. In tropical climates the snow loads may 
 be neglected. 
 
 11. In climates corresponding to that of New York, ordinary roofs, 
 up to 80 ft. span, shall be proportioned to carry the following mini- 
 mum loads, per square foot of exposed surface, applied vertically, 
 to provide for dead, wind and snow loads combined: 
 
9 
 
 Slate : 
 
 Gravel or C On boards, flat slope, 1 to 6, or less. .. .50 Ib. 
 Composition J On boards, steep slope, more than 1 to 6. .45 " 
 
 Roofing: ( On 3-in. flat tile or cinder concrete 60 " 
 
 Corrugated sheeting, on boards or purlins 40 " 
 
 On boards or purlins 50 " 
 
 On 3-in. flat tile or cinder concrete 65 " 
 
 Tile, on steel purlins 55 " 
 
 Glass 45 " 
 
 12. For roofs in climates where no snow is likely to occur, reduce 
 the foregoing loads by 10 Ib. per sq. ft., but no roof or any part thereof 
 shall be designed for less than 40 Ib. per sq. ft. 
 
 13. For columns, the specified uniform live loads per square foot 
 shall be used, with a minimum of 20,000 Ib. per column. 
 
 14. For columns carrying more than five floors, these live loads 
 may be reduced as follows: 
 
 For columns supporting the roof and top floor, no reduction; 
 
 For columns supporting each succeeding floor, a reduction of 
 
 5% of the total live load may be made until 50% is reached, 
 
 which reduced load shall be used for the columns supporting all 
 
 remaining floors. 
 
 This reduction is not to apply to live load on columns of ware- 
 houses, and similar buildings which are likely to be fully loaded on 
 all floors at the same time. 
 
 15. The live loads on foundations shall be assumed to be the same 
 as for the footings of columns. The areas of the bases of the founda- 
 tions shall be proportioned for the dead load only. That foundation 
 which receives the largest ratio of live to dead load shall be selected 
 and proportioned for the combined dead and live loads. The dead 
 load on this foundation shall be divided by the area thus found, and 
 this reduced pressure per square foot shall be the permissible working 
 pressure to be used for the dead load of all foundations. 
 
 UNIT STRESSES AND PROPORTION OF PARTS. 
 Substructure. 
 
 16. Pressure on foundations not to exceed, in tons per square foot: 
 
 Soft clay 1 
 
 Ordinary clay and dry sand mixed with clay 2 
 
 Dry sand and dry clay 3 
 
 Hard clay and firm, coarse sand 4 
 
 Firm, coarse sand and gravel . . 6 
 
 Live Loads 
 on Columns. 
 
 Reduction of 
 Live Load 
 on Columns. 
 
 Loads on 
 Foundations. 
 
 Foundations. 
 
10 
 
 Masonry. 17. Working pressure in masonry not to exceed the following: 
 
 Tons per Lb. per 
 sq. ft. sq. in. 
 
 Common brick, Portland-cement mortar 12 168 
 
 Hard-burned brick, Portland-cement mortar.... 15 210 
 
 Rubble masonry, Portland-cement mortar 10 140 
 
 Coursed rubble, Portland-cement mortar 12 168 
 
 First-class masonry, sandstone 20 280 
 
 " " " limestone or bluestone 25 350 
 
 " " " granite 30 420 
 
 Concrete for walls: 
 
 Portland cement 1:2:5 20 280 
 
 " " 1:2:4 25 350 
 
 Pressure of 18. The pressure of beams, girders, wall-plates, column bases, etc., 
 
 on masonry shall not exceed the following, in pounds per square inch : 
 
 On brickwork with cement mortar 300 
 
 " rubble masonry with cement mortar. 250 
 
 " Portland-cement concrete 1:2:4 600 
 
 " first-class sandstone (dimension stone) 400 
 
 " " " limestone 500 
 
 " " granite 600 
 
 Bearing 19. The maximum load carried by any pile shall not exceed 40,000 
 
 Timber Piles. lb., or 600 lb. per sq. in. of its average cross-section. 
 
 Piles driven in firm soil to rock may be loaded to the above limits. 
 Piles driven through loose, wet soil to solid rock, or equivalent bearing, 
 shall be figured as columns with a maximum unit stress of 600 lb. 
 per sq. in., properly reduced. 
 
 Masonry Pillars and Walls Laid in Cement Mortar. 
 
 Pillars. 20. Pillars of brick or stone masonry, with concentric loading, 
 
 may be built of a height not exceeding 12 times their diameter or 
 their least lateral dimension ; providing the unit pressure comes within 
 the limits specified for the different classes of masonry. 
 
 21. The dimensions of pillars loaded eccentrically must be such 
 that the center of pressure comes within the middle third of the base 
 and every other horizontal section, and that the maximum unit pres- 
 sure does not exceed the safe working pressure. 
 
 Wails. 22. The thickness of a wall depends upon the quality of the material 
 
 used, the load it has to carry, and upon its unsupported height or 
 
11 
 
 length. The minimum thickness of a wall of brick or ashlar masonry 
 shall be T V of its least unsupported distance, either vertically or hori- 
 zontally; and that of walls of rubble masonry, of that distance. 
 
 23. The minimum thickness of brick enclosure walls shall be 12 
 in., and that of stone walls, 18 in. 
 
 24. The minimum thickness of curtain walls in the steel skeleton 
 type of buildings shall be 12 in. 
 
 25. The unsupported height of a wall shall be taken as the height 
 of one story, provided it is properly anchored to the floor construc- 
 tion of each story. The unsupported distance horizontally shall be 
 taken as the distance between lateral walls which are properly bonded 
 to it, or the distance between buttresses or steel columns. 
 
 26. In a wall carrying joists or beams, the load may be consid- 
 ered as distributed, if the distance between the beams is not more 
 than twice the thickness of the wall. If a wall has to support con- 
 centrated loads, such as are produced by heavy roof trusses or floor 
 girders, it must be reinforced by buttresses, which should be com- 
 puted as pillars. 
 
 27. In the case of buildings several stories in height, the mini- 
 mum thickness of the exterior walls supporting floors and roof may be 
 approximately determined by the following empirical formula, which 
 gives results agreeing with the provisions of most of the existing 
 building laws. 
 
 28. The thickness of wall in inches t = -r + 
 
 4 
 
 TT 
 
 TT 
 
 
 6 
 
 where L = unsupported length in feet, which should not be assumed 
 less than 24 ft., and H^ fT 2 , JT 3 , etc., the heights of the stories in feet, 
 commencing at the top. 
 
 29. The above rules apply to walls of brick and ashlar masonry 
 for dwellings, hotels and office buildings. 
 
 30. The cellar wall shall generally.be 4 in. thicker than the wall 
 immediately above it, to a depth of 12 ft. below the grade line; and for 
 every additional 10 ft., or part thereof, shall be increased 4 in. Cellar 
 and foundation walls of masonry shall be 4 in. thicker than brick walls. 
 
 31. If any horizontal section through any bearing wall shows more 
 than 30% area of flues or openings, such wall shall be increased in 
 thickness 1 in. for every 4%, or fraction thereof, by which the total 
 areas of flues and openings exceed 30 per cent. 
 
 Exterior 
 Walls. 
 
 Curtain 
 Walls. 
 
 Bearing 
 Walls. 
 
 Cellar and 
 
 Foundation 
 
 Walls. 
 
12 
 
 Non-bearing 
 Walls. 
 
 Permissible 
 Stresses. 
 
 Tension. 
 
 Compression. 
 
 Bending. 
 
 Shear. 
 
 Bearing. 
 
 Axial 
 Compression. 
 
 Provision for 
 
 Eccentric 
 
 Loading. 
 
 Expansion 
 Rollers. 
 
 Combined 
 Stresses. 
 
 32. The thickness of non-bearing walls may be 4 in. less than that 
 of bearing walls, provided that no non-bearing wall is less than 12 in. 
 thick. 
 
 STEEL SUPERSTRUCTURE. 
 
 Unit Stresses. 
 
 33. All parts of the structure shall be proportioned so that the 
 sum of the dead and live loads, together with the impact, if any, 
 shall not cause the stresses to exceed the following amounts in pounds 
 per sq. in. : 
 
 34. Tension, net section, rolled steel 16 000 
 
 35. Direct compression, rolled steel and steel castings 16 000 
 
 36. Bending, on extreme fibers of rolled shapes, built sec- 
 
 tions, girders and steel castings, net section 16 000 
 
 On extreme fibers of pins 24 000 
 
 37. Shear, on rivets and pins 12 000 
 
 On bolts and field rivets 10 000 
 
 On plate-girder web (gross section) . .10 000 
 
 38. Bearing pressure, on pins and rivets 24 000 
 
 On bolts and field rivets 20 000 
 
 39. Axial compression on gross section of columns. . .16 000 70 -- 
 
 with a maximum of 14 000 
 
 Where I = effective length* of member in inches; 
 
 r = corresponding radius of gyration of the section, in 
 inches. 
 
 40. For bracing and the combined stresses due to wind and other 
 loading, the permissible working stresses may be increased 25%, or 
 to 20,000 Ib. for direct compression or tension. 
 
 41. In proportioning columns, provision must be made for ec- 
 centric loading. 
 
 42. The pressure per linear inch on expansion rollers shall not 
 exceed 600 d, where d diameter of rollers, in inches. 
 
 43. Members subject to the action of both axial and bending 
 stresses shall be proportioned so that the greatest fiber stress will not 
 exceed the allowed limits in that member. 
 
 * The effective length " I ", if L is the length of the member between centres of con- 
 nections, shall be t&ken as follows : 
 
 I = L, if both ends are hinged or butting ; 
 
 I = 14 L, if both ends are fixed ; 
 
 I = % L, if one end is fixed, the other hinged ; 
 
 I = 2 L, if one end is fixed, the other free to move. 
 
13 
 
 44. Members subject to alternate stresses of tension and com- 
 pression shall be proportioned for the stress giving the largest sec- 
 tion, but their connections shall be proportioned for the sum of the 
 stresses. 
 
 45. Net sections must be used in calculating tension members, 
 and, in deducting the rivet holes, they must be taken J in. larger 
 than the nominal size of the rivets. 
 
 46. Pin-connected riveted tension members shall have a net sec- 
 tion through the pin holes 25% in excess of the net section of the 
 body of the member. The net section back of the pin hole shall be 
 at least 0.75 of the net section through the pin hole. 
 
 47. The effective length of main compression members shall not 
 exceed 125 times their least radius of gyration, and those for wind 
 and lateral bracing, 150 times, their least radius of gyration. 
 
 48. The length of riveted tension members in horizontal or in- 
 clined positions shall not exceed 200 times their radius of gyration 
 about the horizontal axis. The horizontal projection of the unsup- 
 ported portion of the member is to be considered as the effective length. 
 
 49. Plate girders shall be proportioned on the assumption that 
 one-eighth of the gross area of the web is available as flange area. 
 The thickness of the web plate shall not be less than T D of the unsup- 
 ported distance between flange angles. 
 
 50. The compression flange shall have at least the same sectional 
 area as the tension flange; nor shall the strain per square inch on the 
 
 gross area exceed 16 000 200 p if cover consists of flat plates, or 
 
 16 000 150 -.. if cover consists of a channel section, where I = un- 
 o 
 
 supported distance, and b = width of flange in inches. 
 
 51. The web shall have stiffeners at the ends and inner edges of 
 bearing plates, and at all points of concentrated loads, and also at 
 intermediate points, when the thickness of the web is less than 
 one-sixtieth of the unsupported distance between flange angles, gen- 
 erally not farther apart than the depth of the full web plate, with a 
 maximum limit of 5 ft. 
 
 52. IE -beams, and channels used as beams or girders, shall be pro- 
 portioned by their moments of inertia. 
 
 53. The depth of rolled beams in floors shall be not less than one- 
 twentieth of the span, and, if used as roof purlins, not less than one- 
 thirtieth of the span. 
 
 Alternate 
 Stresses. 
 
 Net 
 Sections. 
 
 Limiting 
 Length of 
 Members. 
 
 Plate 
 Girders. 
 
 Compression 
 Flanges of 
 Plate 
 Girders. 
 
 Web 
 
 Stiffeners. 
 
 Rolled 
 Beams. 
 
 Limiting 
 Depth of 
 Beams and 
 Girders. 
 
14 
 
 Permissible 
 Stresses. 
 
 Timber. 
 
 Timber 
 Columns. 
 
 54. In case of floors subject to shocks and vibrations, the depth 
 of beams and girders shall be limited to one-fifteenth of the span. If 
 shallower beams are used, the sectional area shall be increased until 
 the maximum deflection is not greater than thai? of a beam having a 
 depth of one-fifteenth of the span, but the depth of such beams and 
 girders shall in no case be less than one-twentieth of the span. 
 
 Cast Iron. 
 
 55. Compression 12 000 Ib. per sq. in. 
 
 Tension 2 500 " " " " 
 
 Shear 1 500 " " " " 
 
 Timber. 
 
 56. The timber parts of the structure shall be proportioned in 
 accordance with the following stresses, given in pounds per square 
 inch: 
 
 Kind of timber. 
 
 Transverse 
 loadipg. 
 
 End 
 bearing. 
 
 Columns 
 under 10 
 diameters. 
 
 Bearing 
 across 
 fiber. 
 
 Shear 
 along fiber. 
 
 White Oak 
 
 1 200 
 
 1 200 
 
 1 000 
 
 500 
 
 200 
 
 Long-Leaf Yellow Pine 
 
 1 500 
 
 1 500 
 
 1 000 
 
 350 
 
 100 
 
 White Pine and Spruce 
 Hemlock 
 
 1 000 
 800 
 
 1 000 
 
 800 
 
 600 
 500 
 
 200 
 200 
 
 100 
 100 
 
 
 
 
 
 
 
 57. Columns may be used with a length not exceeding 45 times 
 the least dimension. The unit stress for lengths of 'more than 10 
 times the least dimension shall be reduced by the following formula : 
 
 Planking. 
 
 Minimum 
 Thickness of 
 Material. 
 
 Adjustable 
 Members. 
 
 Symmetrical 
 Sections. 
 
 100 d 
 
 Where G equals unit stresses, as given above for short columns ; 
 I " length of column, in inches; 
 d " least side of column, in inches. 
 
 58. For the thickness of floor and roof planking, see Table 6. 
 
 DETAILS OF STEEL CONSTRUCTION. 
 
 59. No steel of less than i in. thickness shall be used, except for 
 lining or filling vacant spaces. 
 
 60. Adjustable members in any part of structures shall preferably 
 be avoided. 
 
 61. Sections shall preferably be made symmetrical. 
 
15 
 
 Beam 
 Girder. 
 
 Wall Ends 
 of Beams and 
 Girders. 
 
 Wall-Plates 
 and Column 
 
 62. The strength of connections shall be sufficient to develop the Connections, 
 full strength of the member. 
 
 63. No connection, except lattice bars, shall have less than two 
 rivets. 
 
 64. Floor beams shall generally be rolled-steel beams. Floor Beams. 
 
 65. For fire-proof floors, they shall generally be tied with tie-rods 
 at intervals not exceeding eight times the depth of the beams. This 
 spacing may be increased for floors which are not of the arch type 
 of construction. Holes for tie-rods, where the construction of the 
 floor permits, shall be spaced about 3 in. above the bottom of the beam. 
 
 66. When more than one rolled beam is used to form a girder, 
 they shall be connected by bolts and separators at intervals of not 
 more than 5 ft. All beams having a depth of 12 in. and more shall 
 have at least two bolts to each separator. 
 
 67. Wall ends of a sufficient number of joists and girders shall be 
 anchored securely to impart rigidity to the structure. 
 
 68. Wall-plates and column bases shall be constructed so that the 
 load will be well distributed over the entire bearing. If they do not 
 get the full bearing on the masonry, the deficiency shall be made 
 good with Portland-cement mortar. 
 
 69. The floor girders may be rolled beams or plate girders; they 
 shall preferably be riveted or bolted to columns by means of connection 
 angles. Shelf angles or other supports may be provided for convenience 
 during erection. 
 
 70. The flange plates of all girders shall be limited in width, so as 
 not to extend beyond the outer line of rivets connecting them to the 
 angles more than 6 in., or more than eight times the thickness of the 
 thinnest plate. 
 
 71. Web stiffeners shall be in pairs, and shall have a close bearing 
 against the flange angles. Those over the end bearing, or forming the 
 connection between girder and column, shall be on fillers. Intermediate 
 stiffeners may be on fillers or crimped over the flange angles. The 
 rivet pitch in stiffeners shall not be more than 5 in. 
 
 72. Web plates of girders must be spliced at all points by a plate web Splices, 
 on each side of the web, capable of transmitting the full stress through 
 
 splice rivets. 
 
 73. Columns shall be designed so as to provide for effective con- Columns, 
 nections of floor beams, girders or brackets. 
 
 They shall preferably be continuous over several stories. 
 
 Floor 
 Girders. 
 
 Flange 
 Plates. 
 
 Web 
 
 Stiffeners. 
 
16 
 
 Column 
 Splices. 
 
 Trusses. 
 
 Intersecting 
 Members. 
 
 Roof Trusses. 
 
 Eye-Bars. 
 
 Spacing of 
 Rivets. 
 
 Edge 
 Distance. 
 
 Maximum 
 Diameter. 
 
 74. The splices shall be strong enough to resist the bending stress 
 and make the columns practically continuous for their whole length. 
 
 75. Trusses shall preferably be riveted structures. Heavy trusses, 
 of long span, where the riveted field connections would become un- 
 wieldy, or for other good reasons, may be designed as pin-connected 
 structures. 
 
 76. Main members of trusses shall be designed so that the neutral 
 axes of intersecting members shall meet in a common point. 
 
 77. Roof trusses shall be braced in pairs in the plane oi the chords. 
 Purlins shall be made of rolled shapes, plate girders or lattice 
 
 girders. 
 
 78. The eye-bars in pin-connected trusses composing a member 
 shall be as nearly parallel to the axis of the truss as possible. 
 
 79. The minimum distance between centers of rivet holes shall be 
 three diameters of the rivet; but the distance shall preferably be 
 not less than 3 in. for |-in. rivets, 2 in. for f-in. rivets, and If in. 
 for -in. rivets. The maximum pitch in the line of the stress for 
 members composed of plates and shapes shall be 6 in. for |-in. rivets, 
 5 in. for f-in. rivets, 4 in. for |-in. rivets and 4 in. for ^-in. rivets. 
 
 80. For angles with two gauge lines, with rivets staggered, the 
 maximum in each line shall be twice as great as given in Paragraph 
 79; and, where two or more plates are used in contact, rivets not more 
 than 12 in. apart in either direction shall be used to hold the plates 
 together. 
 
 81. The pitch of the rivet, in the direction of the stress, shall not 
 exceed 6 in., nor 16 times the thinnest outside plate connected, and 
 not more than 50 times that thickness at right angles to the stress. 
 
 82. The minimum distance from the center of any rivet hole to a 
 sheared edge shall be 1 in. for -in. rivets, 1 in. for f-in. rivets, 
 1| in. for |-in. rivets, and 1 in. for -in. rivets; and to a rolled edge, 
 1, 1|, 1 and | in., respectively. 
 
 83. The maximum distance from any edge shall be eight times 
 the thickness of the plate. 
 
 84. The diameter of the rivets in any angle carrying calculated 
 stresses shall not exceed one-quarter of the width of the leg in which 
 they are driven. In minor parts, rivets may be in. greater in 
 diameter. 
 
IT 
 
 Tie- 
 Plates. 
 
 85. The pitch of rivets at the ends of built compression members Pitch at 
 
 Ends. 
 
 shall not exceed four diameters of the rivets for a length equal to one 
 and one-half times the maximum width of the member. 
 
 86. The open sides of compression members shall be provided with 
 lattice, having tie-plates at each end and at intermediate points where 
 the lattice is interrupted. The tie-plates shall be as near the ends 
 as practicable. In main members, carrying calculated stresses, the 
 end tie-plates shall have a length not less than the distance between 
 the lines of rivets connecting them to the flanges, and intermediate 
 ones not less than half this distance. 
 
 Their thickness shall be not less than one-fiftieth of the same 
 distance. 
 
 87. The latticing of compression members shall be proportioned Lattice, 
 to resist the shearing .stresses corresponding to the allowance for flex- 
 ure provided in the column formula in Paragraph 39 by the term 70 
 
 The minimum thickness of lattice bars shall be one-fortieth for single 
 lattice and one-sixtieth for double lattice, of the distance between end 
 rivets; their minimum width shall be as follows: 
 
 For 15-in. channels, or built sections with 3 
 and 4-in. angles 
 
 For 12, 10 and 9-in. channels, or built sections 
 with 3-in. angles 
 
 j- 2 in. (I-in. rivets) ; 
 
 i 2 in. (f -in rivets) ; 
 
 For 8 and 7-in. channels, or built sections ) n . ,...'.. . \ 
 
 >- 2 in. (| -in. rivets) ; 
 with 2^-in. angles ' 
 
 For 6 and 5-in. channels, or built sections with) . ,, . . \ 
 
 j If in. G-m. rivets). 
 2-in. angles ) 
 
 88. Lattice bars with two rivets shall generally be used in flanges 
 more than 5 in. wide. 
 
 89. The inclination of lattice bars with the axis of the member, Angle of 
 shall generally be not less than 45, and when the distance between 
 
 the rivet lines in the flange is more than 15 in., if a single rivet bar 
 is used, the lattice shall be double and riveted at the intersection. 
 
 90. The pitch of lattice connections, along the flange, divided by Spacing of 
 the least radius of gyration of the member between connections, shall 
 
 be less than the corresponding ratio of the member as a whole. 
 
18 
 
 Faced 91. Abutting joints in compression members when faced for bearing 
 
 shall be spliced sufficiently to hold the connecting members accurately 
 in place. 
 
 92. All other joints in riveted work, whether in tension or com- 
 pression, shall be fully spliced. 
 
 Pin Plates. 93. Pin holes shall be reinforced by plates where necessary ; and at 
 
 least one plate shall be as wide as the flange will allow; where angles 
 are used, this plate shall be on the same side as the angles. The plates 
 shall contain sufficient rivets to distribute their portion of the pin 
 pressure to the full cross-section of the member. 
 
 Pins. 94. Pins shall be long enough to insure a full bearing of all parts 
 
 connected upon the turned-down body of the pin. 
 
 95. Members packed on pins shall be held against lateral movement. 
 
 Bolts. 96. Where members are connected by bolts, the body of these bolts 
 
 shall be long enough to extend through the metal. A washer at least 
 T 3 F in. thick shall be used under the nut. 
 
 Fillers. 97. Fillers between parts carrying stress shall have a sufficient 
 
 number of independent rivets to transmit the stress to the member to 
 which the filler is attached. 
 
 Temperature. 98. Provision shall be made for expansion and contraction, cor- 
 responding to a variation of temperature of 150 Fahr. where necessary. 
 
 Rollers. 99. Expansion rollers shall be not less than 4 in. in diameter. 
 
 stone Bolts. 100. Stone bolts shall extend not less than 4 in. into granite pedes- 
 
 tals and 8 in. into other material. 
 
 Anchorage. 101. Columns which are strained in tension at their base shall be 
 
 anchored to the foundations. 
 
 102. Anchor bolts shall be long enough to engage a mass of 
 masonry, the weight of which shall be one and one-half times the ten- 
 sion in the anchor. 
 
 Bracing. 103. Lateral, longitudinal and transverse bracing in all structure? 
 
 shall preferably be composed of rigid members. 
 
 MATERIAL AND WORKMANSHIP. 
 MATERIAL. 
 
 steel. 104. All parts of the metallic structure shall be of rolled steel, 
 
 except column bases, bearing plates or minor details, which may be of 
 cast iron or cast steel. 
 
19 
 
 105. Steel may be made by the open-hearth or by the Bessemer Process of 
 
 Manufacture. 
 
 process. 
 
 106. The chemical and physical properties shall conform to the Requirements, 
 following limits : 
 
 Chemical and physical properties. 
 
 Structural 
 steel. 
 
 Rivet steel. 
 
 Steel 
 castings. 
 
 Phosphorus, maximum 
 
 0.040/0 
 
 0.050/ 
 
 0.04% 
 0.04% 
 
 0.05% 
 0.059/0 
 
 Sulphur, maximum 
 
 
 Ultimate tensile strength; pounds per 
 square 'inch 
 
 Desired 
 
 60 000 
 1 500 000* 
 
 Desired 
 
 50 000 
 1 500 000 
 
 Not less than 
 65 000 
 
 Elongation: minimum percentage in 8J 
 in i 
 
 Ultimate tensile 
 strength. 
 M 
 
 Silky. 
 180 flat.t 
 
 Ultimate tensile 
 strength. 
 
 ( 
 Elongation: minimum percentage in 2 in. 
 Character of fracture 
 
 18 
 Silky or fine 
 granular. 
 90 
 
 Silky. -j 
 180 flat. 
 
 Cold bends without fracture 
 
 
 * See Paragraph 117. t See Paragraphs 118, 119 and 120. See Paragraph 121. 
 
 107. In order that the ultimate strength of full-sized annealed 
 eye-bars may meet the requirements of Paragraph 170, the ultimate 
 strength in test specimens may be determined by the manufacturers ; 
 all other tests than those for ultimate strength shall conform to the 
 above requirements. 
 
 108. The yield point, as indicated by- the drop of beam, shall be 
 recorded in the test reports. 
 
 109. Tensile tests of steel showing an ultimate strength within 
 5,000 Ib. of that desired will be considered satisfactory. 
 
 110. Chemical determinations of the percentages of carbon, phos- 
 phorus, sulphur and manganese shall be made by the manufacturer 
 from a test ingot taken at the time of the pouring of each melt of 
 steel, and a correct copy of such analysis shall be furnished to the 
 engineer or his inspector. 
 
 111. Specimens for tensile and bending tests for plates, shapes and 
 bars shall be made by cutting coupons from the finished product, which 
 shall have both faces rolled and both edges milled to the form shown 
 by Fig. 1; or with both edges parallel; or they may be turned to a 
 diameter of f in. for a length of at least 9 in., with enlarged ends. 
 
 112. Rivet rods shall be tested as rolled. 
 
 113. Specimens shall be cut from the finished rolled or forged bar, 
 in such manner that the center of the specimen shall be 1 in. from 
 the surface of the bar. The specimen for the tensile test shall be 
 
 Allowable 
 Variations. 
 
 Chemical 
 Analyses. 
 
 Form of 
 Specimens 
 for Plates, 
 Shapes and 
 Bars. 
 
 Rivets. 
 
 Pins and 
 Rollers. 
 
turned to the form shown by Fig. 2. The specimen for the bending 
 test shall be.l in. by % in. in section. 
 
 Steel 
 Castings. 
 
 Specimens of 
 Rolled Steel. 
 
 Number of 
 Tests. 
 
 Modifications 
 in Elonga- 
 tion. 
 
 Bending 
 Tests. 
 
 Thick 
 Material. 
 
 Bending 
 Angles. 
 
 / 
 
 About 3" ? JParallei Section 
 
 ;,$> j " Not less than 9" j 
 
 1 
 
 v j IK" ! 
 
 
 
 j, , ? . .!: 
 
 
 
 ^^i^i^Etc. 
 
 fc 
 
 
 FIG. l. 
 
 
 FIG. 2. 
 
 114. The number of tests will depend on the character and im- 
 portance of the castings. Specimens shall be cut cold from coupons 
 moulded and cast on some portion of one or more castings from each 
 melt, or from the sink-heads, if the heads are of sufficient size. The 
 coupon or sink-head, so used, shall be annealed with the casting before 
 it is cut off. Test specimens shall be of the form prescribed for pins 
 and rollers. 
 
 115. Rolled steel shall be tested in the condition in which it comes 
 from the rolls. 
 
 116. At least one tensile and one bending test shall be made from 
 each melt of steel as rolled. In case steel differing in. and more in 
 thickness is rolled from one melt, a test shall be made from the 
 thickest and thinnest material rolled. 
 
 117. For material more than f in. in thickness, 'a deduction of 1% 
 will be allowed from the specified elongation for each J in. in thickness 
 above | in. 
 
 118. Bending tests may be made by pressure or by blows. Plates, 
 shapes and bars less than 1 in. thick shall bend as called for in Para- 
 graph 106. 
 
 119. Full-sized material for eye-bars and other steel 1 in. or more 
 in thickness, tested or rolled, shall bend cold 180 around a pin, the 
 diameter of which is equal to twice the thickness of the bar, without 
 fracture on the outside of the bend. 
 
 120. Angles f in. and less in thickness shall open flat, and angles \ 
 in. and less in thickness shall bend shut, cold, under blows of a ham- 
 
21 
 
 Nicked 
 Bends. 
 
 Defective 
 Material. 
 
 mer, without sign of fracture. This test will be made only when re- 
 quired by the inspector. 
 
 121. Kivet steel, when nicked and bent around a bar of the same 
 diameter as the rivet rod, shall give a gradual break and a fine, silky, 
 uniform fracture. 
 
 122. Finished material shall be free from injurious seams, flaws, Finish, 
 oracks, defective edges, or other defects, and shall have a smooth, 
 uniform, workmanlike finish. Plates 36 in. and less in width shall 
 
 have rolled edges. 
 
 123. Every finished piece of steel shall have the melt number and stamping 
 the name of the manufacturer stamped or rolled upon it. Steel for 
 
 pins and rollers shall be stamped on the end. Rivet and lattice steel 
 and other small parts may be bundled with the above marks on an at- 
 tached tag. 
 
 124. Material which, subsequent to the foregoing tests at the mills, 
 and its acceptance there, develops weak spots, brittleness, cracks or 
 other imperfections, or is found to have injurious defects, will be re- 
 jected at the shop, and shall be replaced by the manufacturer at his own 
 cost. 
 
 125. A variation in cross-section or weight in the finished members 
 of more than 2% from that specified "will be sufficient cause for re- 
 jection. 
 
 126. Iron castings shall be made of tough, gray iron, free from in- cast iron, 
 jurious cold-shuts or blow-holes, true to pattern and of workmanlike 
 
 finish. Test pieces 1| in. round shall be capable of sustaining on a clear 
 span of 12 in. a central load of at least 2 900 lb., and deflect at least 
 TO- in. before rupture. 
 
 WORKMANSHIP. 
 
 127. All parts forming a structure shall be built in accordance with General, 
 approved drawings. The workmanship and finish shall be equal to the 
 
 best practice in modern bridge works. 
 
 128. Material shall be thoroughly straightened in the shop, by 
 methods which will not injure it, before being laid off or worked in any 
 way. 
 
 129. Shearing shall be done neatly and accurately, and all portions Finish, 
 of the work exposed to view shall be neatly finished. 
 
 130. The size of rivets called for on the plans shall be understood to Rivets, 
 mean the actual size of the cold rivet before heating. 
 
 Allowable 
 Variation 
 in Weight. 
 
 Straightening 
 Material. 
 
Rivet 
 Holes. 
 
 Punching. 
 
 Assembling. 
 
 Lattice Bars. 
 
 Web 
 Stiffeners. 
 
 Splice Plates 
 and Fillers. 
 
 Connection 
 Angles. 
 
 Riveting. 
 
 Heating of 
 Rivets. 
 
 Rivets. 
 
 Field Bolts. 
 
 Members to 
 be Straight. 
 
 131. The diameter of the punch for material not more than f in. 
 thick shall be not more than T V in., nor that of the die more than | 
 in. larger than the diameter of the rivet. Material more than f in. thick, 
 excepting in minor details, shall be sub-punched and reamed or drilled 
 from the solid. 
 
 132. Punching shall be done accurately. Slight inaccuracy in the 
 matching of holes may be corrected with reamers. Drifting to enlarge 
 unfair holes will not be allowed. Poor matching of holes will be 
 cause for rejection, at the option of the inspector. 
 
 133. Riveted members shall have all parts well pinned up and 
 firmly drawn together with bolts before riveting is commenced. Con- 
 tact surfaces shall be painted. (See Paragraph 157.) 
 
 134. Lattice bars shall have neatly rounded ends, unless otherwise 
 called for. 
 
 135. Stiffeners shall fit neatly between the flanges of girders. Where 
 tight fits are called for, the ends of the Stiffeners shall be faced and 
 shall be brought to a true contact bearing with the flange angles. 
 
 136. Web splice plates and fillers under Stiffeners shall be cut to 
 fit within i in. of flange angles. 
 
 137. Connection angles for floor girders shall be flush with each 
 other and correct as to position and length of girder. 
 
 138. Rivets shall be driven by pressure tools wherever possible. 
 Pneumatic hammers shall be used in preference to hand driving. 
 
 139. Rivets shall be heated to a light cherry-red heat in a gas or 
 oil furnace. The furnace must be so constructed that it can be adjusted 
 to the proper temperature. 
 
 140. Rivets shall look neat and finished, with heads of approved 
 shape, full, and of equal size. They shall be central on the shank and 
 shall grip the assembled pieces firmly. Recupping and caulking will 
 not be allowed. Loose, burned, or otherwise defective rivets shall be cut 
 out and replaced. In cutting out rivets, great care shall be taken 
 not to injure the adjoining metal. If necessary, they shall be drilled 
 out. 
 
 141. Wherever bolts are used in place of rivets which transmit 
 shear, such bolts must have a driving fit. A washer not less than in. 
 thick shall be used under the nut. 
 
 142. The several pieces forming one built member shall be straight 
 and shall fit closely together, and finished members shall be free from 
 twists, bends or open joints. 
 
23 
 
 143. Abutting joints shall be cut or dressed true and straight and 
 fitted closely together, especially where open to view. In compression 
 joints depending on contact bearing, the surfaces shall be truly faced, 
 so as to have even bearings after they are riveted up complete and 
 when perfectly aligned. 
 
 144. Eye-bars .shall be straight and true to size, and shall be free 
 from twists, folds in the neck or head, or any other defect. Heads shall 
 be made by upsetting, rolling or forging. Welding will not be allowed. 
 The form of the heads will be determined by the dies in use at the 
 works where the eye-bars are made, if satisfactory to the engineer, 
 but the manufacturer shall guarantee the bars to break in the body 
 when tested to rupture. The thickness of the head and neck shall not 
 vary more than ^ in. from that specified. 
 
 145. Before boring, each eye-bar shall be perfectly annealed and 
 carefully straightened. Pin holes shall be in the center line of bars and 
 in the center of heads. Bars of the same length shall be bored so 
 accurately that, when placed together, pins -^ in. smaller in diameter 
 than the pin holes can be passed through the holes at both ends of 
 the bars at the same time. 
 
 146. Pin holes shall be bored true to gauges, smooth and straight; at 
 right angles to the axis of the member, and parallel to each other, un- 
 less otherwise called for. Wherever possible, the boring shall be done 
 after the member is riveted up. 
 
 147. The distance from center to center of pin holes shall be cor- 
 rect within -fa in., and the diameter of the hole not more than ^o in. 
 larger than that of the pin, for pins up to 5 in. diameter, and ^ in. 
 for larger pins. 
 
 148. Pins and rollers shall be turned accurately to gauges, and shall 
 be straight, smooth and entirely free from flaws. 
 
 149. At least one pilot and driving nut shall be furnished for each 
 size of pin for each structure. 
 
 150. Screw threads shall make tight fits in the nuts, and shall be 
 United States standard, except for diameters greater than If in., when 
 they shall be made with six threads per inch. 
 
 151. Steel, except in minor details, which has been partially heated 
 shall be properly annealed. 
 
 152. All steel castings shall be annealed. 
 
 153. Welds in steel will not be allowed. 
 
 Finish of 
 Joints. 
 
 Eye- Bars. 
 
 Boring 
 Eye-Bars. 
 
 Pin Holes. 
 
 Variation in 
 Pin Holes. 
 
 Pins and 
 Rollers. 
 
 Pilot Nuts. 
 
 Screw 
 Threads. 
 
 Annealing. 
 
 Steel 
 Castings. 
 
 Welds. 
 
24 
 
 Bed-Plates. 
 
 Shipping 
 Details. 
 
 Shop 
 Painting. 
 
 Field 
 Painting. 
 
 Facilities for 
 Inspection. 
 
 Access to 
 Shop. 
 
 Mill Orders. 
 
 154. Expansion bed-plates shall be planed true and smooth. Cast 
 wall-plates shall be planed at top and bottom. The cut of the planing 
 tool shall correspond with the direction of expansion. 
 
 155. Pins, nuts, bolts, rivets and other small details shall be boxed 
 or crated. 
 
 PAINTING. 
 
 156. Steelwork, before leaving the shop, shall be thoroughly cleaned 
 and given one good coating of pure linseed oil, or such paint as may 
 be called for, well worked into all joints and open spaces. 
 
 157. In riveted work, the surfaces coming in contact shall be 
 painted before being riveted together. 
 
 158. Pieces and parts which are not accessible for painting after 
 erection shall have two coats of paint before leaving the shop. 
 
 159. Steelwork to be entirely embedded in concrete shall not be 
 painted. 
 
 160. Painting shall be done only when the surface of the metal 
 is perfectly dry. It shall not be done in wet or freezing weather, unless 
 protected under cover. 
 
 161. Machine-finished surfaces shall be coated with, white lead 
 and tallow before shipment, or before being put out into the open air. 
 
 162. After the structure is erected, the metal-work shall be painted 
 thoroughly and evenly with an additional coat of paint, mixed with 
 pure linseed oil, of such quality and color as may be selected. Suc- 
 ceeding coats of paint shall vary somewhat in color, in order that 
 there may be no confusion as to the surfaces which have been 
 painted. 
 
 INSPECTION AND TESTING. 
 
 163. The manufacturer shall furnish all facilities for inspecting and 
 testing the weight, quality of material and workmanship. He shall 
 furnish a suitable testing machine for testing the specimens, as well as 
 prepare the pieces for the machine, free of cost. 
 
 164. When an inspector is furnished by the purchaser, he shall have 
 full access at all times to all parts of the works where material under 
 his inspection is manufactured. 
 
 165. The purchaser shall be furnished with complete copies of 
 mill orders, and no material shall be rolled and no work done before 
 he has been notified as to where the orders have been placed, so that 
 he may arrange for the inspection. 
 
25 
 
 . T 
 Invoices. 
 
 166. The purchaser shall also be furnished with complete shop ghop Plans, 
 plans, and must l^e notified well in advance of the start of the work in 
 
 the shop, in ordei that he may have an inspector on hand to inspect 
 the material and workmanship. 
 
 167. Complete copies of shipping invoices shall be furnished to 
 the purchaser with each shipment. 
 
 168. If the inspector, through an oversight or otherwise, has ac- Accepting 
 cepted material or work which is defective or contrary to the specifica- or Work, 
 tions, this material, no matter in what stage of completion, may be 
 rejected by the purchaser. 
 
 FULL-SIZED TESTS. 
 
 169. Full-sized tests on eye-bars and similar members, to prove 
 the workmanship, shall be made at the manufacturer's expense, and 
 shall be paid for by the purchaser at contract price, if the tests are 
 satisfactory. If the tests are not satisfactory, the members 
 represented by them will be rejected. 
 
 170. In eye-bar tests, the minimum ultimate strength shall be 
 55 000 Ib. per sq. in. The elongation in 10 ft., including fracture, shall 
 be not less than 15%. Bars shall break in the body and the fracture 
 shall be silky or fine granular, and the elastic limit as indicated by the 
 drop of the mercury shall be recorded. Should a bar break in the head 
 and develop the specified elongation, ultimate strength and character 
 of fracture, it shall not be cause for rejection, provided not more 
 than one-third of the total number of bars break in the head. 
 
27 
 
 CONCRETE AND REINFORCED CONCRETE. 
 Concrete, plain and reinforced, may now be considered one of the 
 recognized materials of construction. It has proved to be satisfactory 
 material, when properly used, for those purposes for which its quali- 
 ties make it particularly suitable. 
 
 PROPER USE. 
 
 Concrete is a material of very low tensile strength and capable 
 of sustaining but very small tensile deformations without rupture; 
 its value as a structural material depends chiefly upon its durability, 
 its fire-resisting qualities, its strength in compression and its rela- 
 tively low cost. Its strength generally increases with age. 
 
 Plain, or massive, concrete is well adapted for the construction 
 of massive structural parts, which have to resist compression only, 
 and as a substitute for stone or brick masonry in foundations, walls, 
 piers, arches, culverts, docks, dams, reservoirs, sewers, tunnel lin- 
 ings, etc. 
 
 For such purposes concrete has stood the test of time, and may be 
 used without reinforcement in blocks, or as a monolith. It has these 
 advantages over stone masonry, that material for the aggregate can be 
 found in almost any locality, and the concrete can easily be put in 
 place, under proper supervision, without skilled workmen. Concrete 
 in monolithic form is better adapted to receive reinforcement than 
 stone masonry. 
 
 In substructures and foundations, the bases can be more conveniently 
 and effectively enlarged by reinforcing. For certain kinds of ma- 
 sonry construction for which concrete is now extensively substituted, 
 such as dams, retaining walls, etc., engineers have been able, by the 
 use of proper reinforcement, to depart from the usual forms of con- 
 struction and adopt new ones. 
 
 Owing to its fire-resisting qualities, reinforced concrete is a suit- 
 able material for fire-proof construction for floor and roof slabs, curtain 
 
 walls, partitions, etc. 
 
 IMPROPER USE. 
 
 Failures of reinforced concrete structures are usually due to any 
 one or a combination of the following causes: Defective design, poor 
 material and faulty execution. 
 
 The defects in a design may be many and various. The computa- 
 tions and assumptions on which they are based may be faulty and 
 
28 
 
 contrary to the established principles of statics; the unit stresses used 
 may be excessive, or the details of the design defective. 
 
 As the properties of concrete and reinforced concrete are not yet 
 as well understood and clearly denned as those of steel, owing to the 
 lack of conclusive tests and experience, and as there is no generally 
 accepted theory in existence at the present time for computing the 
 interior forces in reinforced concrete structures, the data which are 
 now available should be used with caution, so that if there be an error, 
 it will be on the side of safety. 
 
 The design of a structure built of reinforced concrete should, there- ' 
 fore, receive at least the same careful consideration as one of steel, 
 and only engineers with sufficient experience and good judgment should 
 be intrusted with such work. . 
 
 The computations should include all the minor details, which are 
 sometimes of the utmost importance. The design should show clearly 
 the size and position of the reinforcement, and should provide for 
 proper connections between the component parts so that they cannot 
 be displaced. The best results are obtained when the reinforcement 
 of any member is a unit, so that the reinforcement can be put in 
 position without depending on the laborers to put each bar in its 
 proper place. As the connections between the members are generally 
 the weakest points, the design' should provide for proper attach- 
 ments between the reinforcements of connecting members and should 
 be accompanied by computations to prove their strength. 
 
 The use of unwarranted high unit stresses, approaching the danger 
 line, is one of the common defects in the design of reinforced con- 
 crete structures. 
 
 Articulated concrete structures designed in imitation of steel 
 trusses may be mentioned as illustrating the improper use of rein- 
 forced concrete. Long concrete columns, reinforced with longitudinal 
 round or square bars intended to take compression, but which cannot 
 resist buckling, may also be mentioned in this connection. 
 
 Poor material is sometimes used for the concrete, as well as for 
 the reinforcement. Poor concrete is not always used intentionally, 
 but is often allowed to go into the structure owing to the lack of ex- 
 perience of the contractor and his superintendents, or to the absence 
 of proper supervision. 
 
 A poor quality of steel for reinforcement is sometimes called for 
 in the specifications for the purpose of reducing the cost. For steel 
 
29 
 
 structures, a high grade of material is used, while the steel used for 
 reinforcing concrete is sometimes made of old rails or other unsuita- 
 ble, brittle material, which is not fit to be used in any permanent 
 structure. 
 
 Faulty execution and careless workmanship may generally be at- 
 tributed to unintelligent, insufficient supervision. 
 
 The remarks referring to the improper uses of reinforced con- 
 crete apply more particularly to building construction, where rational 
 design, good material, good workmanship and adequate supervision 
 are the exception rather than the rule. 
 
 While other structures upon the safety of which human lives de- 
 pend are generally designed by engineers employed by the owner, and 
 the contracts let on the engineer's design and specifications, in accord- 
 ance with legitimate practice, reinforced concrete structures are as a 
 rule designed by contractors or engineers commercially interested, and 
 the contract let for a lump sum, without the advice of a competent 
 engineer, and regardless of the merits of the design. 
 
 The construction of buildings in large cities is regulated by mu- 
 nicipal authorities. For reinforced concrete work, however, the lim- 
 ited supervision which municipal inspectors are able to give is not 
 sufficient. Other means for more adequate supervision and inspection 
 should, therefore, be provided. 
 
 RESPONSIBILITY AND SUPERVISION. 
 
 If any failure occurs in an important engineering structure, the 
 engineer is generally held responsible for the same. In recent fail- 
 ures of reinforced concrete buildings, coroners' juries either put the 
 responsibility on unknown causes, or on some ignorant, innocent sub- 
 ordinate, who had to act as scapegoat for his employer. 
 
 Disasters have proved that the execution of the work should not 
 be separated from the designing of the structure. Intelligent, ra- 
 tional supervision and execution of the work can be expected only when 
 both functions are combined. The engineer who prepares the design 
 and specifications should also have the supervision of the execution 
 of the work, and may then he held responsible for its entire construc- 
 tion, unless it can be proven that the contractor has done work con- 
 trary to design, specifications and orders of the engineer, which the 
 engineer and his inspectors were unable to prevent. In this case the 
 contractor should be held responsible. 
 
30 
 
 For the purpose of fixing the responsibility and providing for 
 adequate supervision during construction, the Special Committee on 
 Concrete and Reinforced Concrete of the American Society of Civil 
 Engineers recommends the following rules: 
 
 a. Before work is commenced, complete plans shall be pre- 
 pared, accompanied by specifications, static computations and de- 
 scriptions showing the general arrangement and all details. The 
 static computations shall give the loads assumed separately, such 
 as dead and live loads, wind and impact, if any, and the result- 
 ing stresses. 
 
 Z>. The specifications shall state the qualities of the materials 
 to be used for making the concrete, and the manner in which 
 they are to be proportioned. 
 
 c. The strength which the concrete is expected to attain after a 
 definite period shall be stated in the specifications. 
 
 d. The drawings and specifications shall be signed by the en- 
 gineer and the contractor. 
 
 e. The approval of plans and specifications by other authorities 
 shall not relieve the engineer nor the contractor of responsibility. 
 
31 
 
 SPECIFICATIONS FOR PLAIN AND REINFORCED 
 CONCRETE CONSTRUCTION. 
 
 The following tentative specifications apply to all structures, or 
 parts thereof, built of plain or reinforced concrete: 
 
 DESIGN. 
 
 1. In the design of massive concrete or plain concrete, no account Massive 
 should be taken of the tensile strength of the material, and sections 
 should usually be so proportioned as to avoid tensile stresses. This 
 
 will generally be accomplished, in the case of rectangular shapes, if 
 the line of pressure is kept within the middle third of the section, 
 but in very large structures, such as high masonry dams, a more exact 
 analysis may be required. Structures of massive concrete are able 
 to resist unbalanced lateral forces by reason of their weight, hence the 
 element of weight rather than strength often determines the design. 
 A relatively cheap and weak concrete will therefore often be suitable 
 for massive concrete structures. Owing to its low extensibility, the 
 contraction due to hardening and to temperature changes requires spe- 
 cial consideration, and, except in the case of very massive walls, such 
 as dams, it is desirable to provide joints at intervals to localize the 
 effect of such contraction. The spacing of such joints will depend 
 upon the form and dimensions of the structure and its degree of 
 exposure. 
 
 2. Massive concrete may be used for piers and short columns in 
 which the ratio of length to least width is relatively small. Under 
 ordinary conditions this ratio should not exceed six, but, where the 
 central application of the load is assured, a somewhat higher value 
 may safely be used. 
 
 3. Massive concrete is also a suitable material for arches of moderate 
 span where the conditions as to foundations are favorable. 
 
 4. By the use of metal reinforcement to resist the principal tensile Reinforced 
 stresses, concrete becomes available for general use in a great variety 
 
 of structures and structural forms. This combination of concrete and 
 steel may be used to advantage in the beam, where both compression 
 and tension exist; and the column, where the main stresses are com- 
 pressive, but where cross-bending may exist. The theory of design 
 will therefore relate mainly to the analysis of beams and columns. 
 
GENERAL ASSUMPTIONS FOR STATIC COMPUTATIONS. 
 External Forces. 
 
 5. Buildings of reinforced concrete are to be designed for the same 
 vertical loads and wind pressure as specified on pages 7-9, the weight 
 of reinforced concrete to be assumed at 150 Ib. per cu. ft. 
 
 6. For the computations of the end reactions, moments and shear, 
 the established rules of statics and of elasticity shall be followed. 
 
 7. In order to obtain the maximum values, the most unfavorable 
 positions and distributions of the live load must be considered. 
 
 8. Possible effects of impact may be considered by adding the usual 
 percentage to the live load. 
 
 9. The span length for computations is to be taken as follows : 
 
 a. For beams, the distance between centers of supports; but 
 shall not be taken to exceed the clear span plus the depth of the 
 beam. 
 
 fc. For freely supported floor slabs, the clear span plus the 
 thickness of the slab in the center. 
 
 c. For continuous slabs, the distance center to center of beams. 
 
 10. For continuous beams and slabs, the bending moment at center 
 and at support shall be taken as f of the moment of a freely sup- 
 ported beam of the same span. 
 
 11. For square floor slabs reinforced in both directions and sup- 
 ported on all sides, the bending moment may be taken as of that 
 of a freely supported beam of the same length. 
 
 12. In computing the strength of columns, the possibility of ec- 
 centric loading must be considered. 
 
 13. In the design of T-beams acting as continuous beams, due con- 
 sideration should be given to the compressive stresses at the supports. 
 For beams of T-sections, the width of the floor slab to be considered 
 as part of the beam shall not be more than 8 times the thickness of 
 the slab, or J of the span length of the beam. 
 
 INTERNAL STRESSES. 
 
 14. The internal stresses in reinforced concrete structures shall be 
 determined the same as in the case of homogenous material on the 
 following assumptions : 
 
33 
 
 Moduli of 
 Elasticity. 
 
 15. (a) The stress in any fiber is directly proportionate to the dis- 
 tance of that fiber from the neutral axis. 
 
 16. (fc) The modulus of elasticity of the concrete remains con- 
 stant within the limits of the working stresses fixed in these specifica- 
 tions. In compression, the two materials are, therefore, strained in 
 proportion to their moduli of elasticity. 
 
 17. (c) The bond between the concrete and steel is sufficient to 
 make the two materials act together as a homogeneous solid. 
 
 18. The ratio of the modulus of elasticity of steel to the modulus 
 of elasticity of stone concrete may be taken at 15, and of cinder con- 
 crete at 30. 
 
 19. The tensile strength of the concrete shall be neglected. 
 
 20. When the shearing stresses developed in any part of the constuc- 
 tion exceed the safe working strength of concrete as specified, a suffi- 
 cient amount of reinforcement shall be introduced in such manner 
 that the deficiency in the resistance to shearing is overcome. 
 
 21. When the safe limit of bond between the concrete and the steel 
 is exceeded, some provision must be made for transmitting the strength 
 of the steel to the concrete. 
 
 22. For columns reinforced with shapes that can resist buckling, 
 the computations may be made in the same manner as for homoge- 
 neous material, if, in the areas and moments of resistence, the sec- 
 tion of steel reinforcement is added to that of the concrete with 15 
 times its value. 
 
 23. In columns with concentric loading, buckling need not be con- 
 sidered if the ratio of the effective length to the effective diameter 
 does not exceed 12. The effective diameter to correspond to the 
 assumed theoretical area. 
 
 24. If tensile stresses produced by eccentric loads or bending mo- 
 ments occur in a column, the steel reinforcement on the tension side 
 must be able to resist the same. 
 
 WORKING STRESSES. 
 
 25. The following working stresses are recommended for static 
 loads : 
 
 26. For the steel reinforcement, the unit stresses shall not exceed steel, 
 those specified for other structural steel work. (Paragraph 33, page 12.) 
 
 27. The following working stresses for concrete are based on the Concrete. 
 
 
 Reinforced 
 Columns. 
 
34 
 
 Stone 
 Concrete. 
 
 compressive strength of the concrete, developed after 28 days, when 
 tested in cylinders 8 in. in diameter and 16 in. long: 
 
 ^Bearing 30% of the compressive strength. 
 
 Compression in extreme fiber 25% 
 
 Axial compression in columns. .. . .20% 
 
 Shear 3% 
 
 Bond, rolled bars 3% 
 
 a a 
 
 a 
 
 a 
 
 a a 
 
 28. For stone concrete composed of one part Portland cement and 6 
 parts aggregate, capable of developing an average compressive strength 
 of 2 000 Ib. per sq. in., at 28 days, the working stresses shall not exceed 
 the following: 
 
 Bearing 600 Ib. per sq. in. 
 
 Compression in extreme fiber, r 500 " " 
 
 Axial compression in columns 400 " " " 
 
 Shear 60 " " " 
 
 Bond, rolled bars 60 " " " 
 
 " drawn wire 40" " " 
 
 29. For cinder concrete capable of developing an average com- 
 pressive strength of 750 Ib. per sq. in., at 28 days, the working stresses 
 shall not exceed the following: 
 
 Bearing 225 Ib. per sq. in. 
 
 Compression in extreme fiber 185 " " 
 
 Shear 25 " " " 
 
 Bond 30 " " 
 
 WORKING STRESSES ON REINFORCED COLUMNS. 
 
 30. For axial compression on concrete in columns reinforced against 
 buckling, the same working stresses as those recommended for bear- 
 ing may be used. If in columns reinforced against buckling the re- 
 inforcement is tied together, so that the concrete may be considered 
 as restrained similarly to concrete enclosed in a steel tube, the working 
 strain on the concrete may be increased to 35% of its compressive 
 strength, or approximately 700 Ib. per sq. in. for 2 000 Ib. concrete. 
 
 * Compression applied to a surface of concrete larger than the leaded area, such as 
 the pressure on bed-plates. 
 
35 
 
 DETAILS OF CONSTRUCTION. 
 
 31. The specifications for the design of structural steel work shall 
 also apply to the steel reinforcement of concrete construction. 
 
 32. Plain concrete columns may be used, if the ratio of length to 
 the least side or diameter does not exceed 12, without any reduction 
 in the working stress specified for axial compression. 
 
 33. The reinforcement of columns shall consist of shapes which can 
 resist compression. These shapes shall be rigidly connected by lat- 
 tice bars or tie-plates at proper intervals, so as to form a skeleton 
 column. Only such columns shall be considered as reinforced. 
 
 34. The reinforcement should be provided with proper connections 
 between the bars to hold them in the right place and at the correct 
 distance from the nearest face of the concrete, so as to prevent dis- 
 lodgment during the depositing and compacting of the concrete. 
 
 35. If the reinforcement consists of round or square bars, their 
 lateral spacing should not be less than 1 diameters, center to center; 
 nor should the distance from the side of the beam to the center of the 
 nearest bar be less than 2 diameters. 
 
 36. When the beam or slab is continuous over its support, rein- 
 forcement should be provided at points of negative moment. 
 
 37. In connections between members, such as between columns and 
 girders, and girders and beams, the reinforcements of the connecting 
 members shall be firmly attached to each other. 
 
 38. The concrete outside of the reinforcement is not to be con- 
 sidered as carrying any load. 
 
 39. Plain concrete walls, if made of concrete which will develop an 
 average compressive strength of at least 1 500 Ib. per sq. in. after 28 
 clays, may be of the same thickness as brick walls laid in cement 
 mortar. If properly reinforced in both directions, the thickness may 
 be reduced to two-thirds of that of brick walls. Spandrel and curtain 
 walls of steel skeleton construction shall have a minimum thickness 
 of 8 in. if reinforced with not less than f Ib. of steel per sq. ft. of 
 wall. Partitions, if constructed of reinforced concrete, shall have 
 a minimum thickness of 3 in., and shall be reinforced with not less 
 than ^-in. rods on 12-in. centers, running both vertically and horizon- 
 tally. The filling of panels of the skeleton frames of sheds or mill 
 buildings shall not be less than 4 in. 
 
 Steel Work. 
 
 Plain 
 
 Concrete 
 
 Columns. 
 
 Column 
 Reinforce- 
 ment. 
 
 Beam 
 Reinforce- 
 ment. 
 
 Continuous 
 Beams and 
 Slabs. 
 
 Connections 
 
 Between 
 
 Members. 
 
 Walls. 
 
36 
 
 Fireproofing. 40. In plain coiac*ete columns, the concrete to a depth of 1 in. 
 may be considered as protective covering, and should not be included 
 in the effective section. Under ordinary conditions, the concrete 
 covering over the metal reinforcement in office buildings, hotels and 
 similar structures should be at least 2 in. for girders and columns, li 
 in. for beams, and 1 in. for floor slabs. In stores, warehouses or other 
 buildings where combustible materials are likely to be stored, the thick- 
 ness of the protection should be increased to 3 or 4 in. 
 
 Stone 
 Concrete. 
 
 Cinder 
 Concrete. 
 
 Portland 
 Cement. 
 
 Pine 
 Aggregate. 
 
 MATERIALS AND WORKMANSHIP. 
 
 41. Stone or gravel concrete shall be used in the construction of 
 girders and columns, or any other parts which carry loads or constitute 
 integral parts of the structure. 
 
 42. Cinder concrete may be used for fireproofing, for floor slabs 
 and for parts which do not carry any loads, such as curtain walls, 
 spandrel walls, parapet walls, partitions and filling of panels of steel 
 skeletons of sheds or mill building. 
 
 43. Only Portland cement conforming to the standard specifica- 
 tions of the American Society for Testing Materials shall be used in 
 reinforced concrete work. 
 
 AGGREGATES. 
 
 44. Extreme care should be exercised in selecting the aggregates 
 for mortar and concrete, and careful tests made of the materials for 
 the purpose of determining their qualities and the grading necessary to 
 secure maximum density* or a minimum percentage of voids. 
 
 45. Fine aggregate consists of sand, crushed stone, or gravel screen- 
 ings, passing when dry a screen having -in. diameter holes. It should 
 be preferably of-silicious material, clean, coarse, free from vegetable 
 loam or other deleterious matter. 
 
 46. A gradation of the grain from fine to coarse is generally ad- 
 vantageous. 
 
 47. Mortars composed of one part Portland cement and three parts 
 fine aggregate by weight when made into brique-ttes should show a 
 tensile strength of at least 70% of the strength of 1 : 3 mortar of the 
 same consistency made with the same cement and standard Ottawa 
 sand. 
 
 * A convenient coefficient of density is the ratio of the sum of the volumes of materials 
 contained in a unit volume to the total unit volume. 
 
37 
 
 Coarse 
 Aggregate. 
 
 48. Coarse aggregate consists of 4ect onaterial, such as crushed 
 stone or gravel, which is retained on a screen having ^-in. diameter 
 holes. The particles should be clean, hard, durable, and free from all 
 deleterious material. Aggregates containing soft, flat or elongated par- 
 ticles should be excluded from important structures. A gradation of 
 sizes of the particles is generally advantageous. 
 
 49. The maximum size of the coarse aggregate shall be such that it 
 will not separate from the mortar in laying and will not prevent the 
 concrete from fully surrounding the reinforcement and filling all parts 
 of the forms. Where concrete is used in mass, the size of the coarse 
 aggregate may be such as to pass a 3-in. ring. For reinforced mem- 
 bers a size to pass a 1-in. ring, or a smaller size, may be used. 
 
 50. Where cinder concrete is permissible, the cinders used as the 
 coarse aggregate should be composed of hard, clean, vitreous clinker, 
 free from sulphides, unburned coal, or ashes. 
 
 51. The water used in mixing concrete should be free from oil, 
 acid, strong alkalis, or vegetable matter. 
 
 STEEL. 
 
 52. The steel used for reinforcement shall be of the same quality 
 as specified for structural steelwork in buildings. 
 
 53. Steel wire used for reinforcement should be drawn from rods 
 of basic open-hearth steel of the same quality as that specified for rivet 
 steel. 
 
 54. All steel to be embedded in concrete shall conform to the shape 
 and sections shown on drawings, and shall be delivered unpainted. It 
 shall be thoroughly cleansed from scale, grease, oil and rust, and given 
 a coating of Portland cement grouting before being covered with con- 
 crete. The cleaning of the metal shall be done with suitable scrapers, 
 
 steel brushes or such other tools as may most efficiently clean the 
 \ 
 
 surface. 
 
 CONCRETE. 
 
 55. The materials to be used in concrete shall be carefully selected, 
 of uniform quality, and proportioned with a view to securing as nearly 
 as possible a maximum density. 
 
 56. The unit of measure shall be the barrel, which should be taken unit of 
 as containing 3.8 cu. ft. Four bags containing 94 Ib. of cement each 
 
 shall be considered the equivalent of one barrel. Fine and coarse ag- 
 gregate should be measured separately as loosely thrown into the 
 measuring receptacle. 
 
 Cinders. 
 
 Quality of 
 Water. 
 
 Quality of 
 Steel. 
 
 Wire. 
 
 Measure. 
 
38 
 
 Relation of 
 Fine and 
 Coarse 
 Aggregates. 
 Relation of 
 Cement and 
 Aggregates. 
 
 Mixing. 
 
 Measuring 
 Ingredients. 
 
 Machine 
 Mixing. 
 
 Hand Mixing. 
 
 Consistency. 
 
 Retempering. 
 
 Placing of 
 Concrete. 
 
 57. The fine and coarse aggregates shall be used in such relative 
 proportions as will insure maximum density. 
 
 58. For reinforced concrete construction, a density proportion based 
 on 1 : 6 should generally be used, i. e. } one part of cement to a total 
 of six parts of fine and coarse aggregates measured separately. 
 
 59. In columns, richer mixtures are often required, while for 
 massive masonry or rubble concrete a leaner mixture, of 1:9 or even 
 1 : 12, may be used. 
 
 60. The ingredients of concrete should be thoroughly mixed to the 
 desired consistency, and the mixing should continue until the cement 
 is uniformly distributed and the mass is uniform in color and homo- 
 geneous, since the maximum density and, therefore, the greatest 
 strength of a given mixture depends largely on thorough and complete 
 mixing. 
 
 61. Methods of measurement of the proportions of the various in- 
 gredients, including the water, should be used, which will secure sep- 
 arate uniform measurements at all times. 
 
 62. When the conditions will permit, a machine mixer of a type 
 which insures the uniform proportioning of the materials throughout 
 the mass should be used, since a more thorough and uniform consist- 
 ency can be thus obtained. 
 
 63. When it is necessary to mix by hand, the mixing should be on 
 a water-tight platform, and especial precautions should be taken to 
 turn the materials until they are homogeneous in appearance and color. 
 
 64. The materials shall be mixed wet enough to produce a concrete 
 of such a consistency as will flow into the forms and about the metal 
 reinforcement, and, at the same, time, can be conveyed from the mixer 
 to the forms without separation of the coarse aggregate from the 
 mortar. 
 
 65. Retempering mortar or concrete, i. e., remixing with water 
 after it has partially set, shall not be permitted. 
 
 66. Concrete, after the addition of water to the mix, should be 
 handled rapidly, and in as small masses as is practicable, from the 
 place of mixing to the place of final deposit, and under no circum- 
 stances shall concrete be used that has partially set before final placing. 
 A slow-setting Cement should be used when a long time is likely to 
 occur between mixing and final placing. 
 
 67. The concrete should be deposited in such a manner as will 
 permit the most thorough compacting, such as can be obtained by 
 
39 
 
 working with a straight shovel or slicing tool kept moving up and 
 down until all the ingredients have settled in their proper place by 
 gravity and the surplus water has been forced to the surface. 
 
 68. In depositing the concrete under water, special care should be 
 exercised to prevent the cement from being floated away, and to pre- 
 vent the formation of laitance, which hardens very slowly and forms 
 a poor surface on which to deposit fresh concrete. Laitance is formed 
 in both still and running water, and should be removed before placing 
 fresh concrete. 
 
 69. Before placing the concrete, care should be taken to see that the 
 forms are substantial and thoroughly wetted and the space to be occu- 
 pied by the concrete is free from debris. When the placing of the con- 
 crete is suspended, all necessary grooves for joining future work 
 should be made before the concrete has had time to set. 
 
 70. When work is resumed, concrete previously placed should be 
 roughened, thoroughly cleansed of foreign material and laitance, 
 drenched and slushed with a mortar consisting of one part Portland 
 cement and not more than two parts fine aggregate. 
 
 71. The faces of concrete exposed to premature drying should be 
 kept wet for a period of at least seven days. 
 
 72. Concrete for reinforced structures should not be mixed or de- 
 posited at a freezing temperature, unless special precautions are taken 
 to avoid the use of materials containing frost or covered with ice 
 crystals, and to provide means to prevent the concrete from freezing 
 after being placed in position and until it has thoroughly hardened. 
 
 73. Where the concrete is to be deposited in massive work, its value Rubble 
 
 Concrete, 
 may be improved and its cost materially reduced through the use of 
 
 clean stones thoroughly embedded in the concrete as near together as 
 is possible and still entirely surrounded by concrete. 
 
 74. The forms must have sufficient resistance to bending, as well as 
 to shocks and vibrations due to tamping, and they shall be arranged 
 to be safely removable while their supports are left in place. The 
 forms should be as nearly watertight as possible, to prevent the 
 escaping of the cement. 
 
 75. In removing the forms and supports, all jar and vibration 
 shall be avoided. No forms shall be removed except in the presence 
 of the inspector. After the forms are removed, no patching or plaster- 
 ing shall be done until all surfaces have been inspected and permis- 
 sion given by the engineer. 
 
 Freezing 
 Weather. 
 
 Forms and 
 Supports. 
 
 Removal 
 of Forms. 
 
40 
 
 76. The period which must elapse between the completion of the 
 tamping and the removal of the forms is a matter of judgment and 
 depends upon the weather, the distance between supports, and the 
 weight of the parts of' the structure. The side forms of beams and 
 columns, and the forms of floor slabs up to spans of 5 ft. may be re- 
 moved after the concrete has hardened sufficiently, that is, in a few 
 days, while the supports of beams should not be removed in less than 
 14 days. For longer spans and larger sections, 4 to 6 weeks may be 
 necessary. 
 
 77. In buildings of several stories, the supports of the lower 
 floors shall not be removed until the hardening of the concrete is so 
 far advanced that it can safely carry the load. 
 
 Protection 78. Immediately after the completion of the tamping, the struc- 
 
 structure. tural parts shall be protected against the effect of freezing and pre- 
 mature drying, as well as against vibrations and loads, until the con- 
 crete is sufficiently hardened. 
 
 INSPECTION AND TESTS. 
 
 Facilities for 79. All facilities for inspection of material and workmanship shall 
 Inspection. 
 
 be furnished by the contractor to the engineer and his inspectors, who 
 
 shall have free access to any part of the structure during construction, 
 or to any part of the works in which any part of the material is made. 
 80. Inspection during construction shall cover the following: 
 
 a. The materials. 
 
 b. The correct construction and erection of the forms and 
 supports. 
 
 c. The sizes, shapes and arrangement of the reinforcement. 
 
 d. The proportioning, mixing and placing of the concrete. 
 
 e. The strength of the concrete by tests of standard test pieces 
 made on the work. 
 
 f. Whether the concrete is sufficiently hardened before the 
 forms and supports are removed. 
 
 g. Prevention of injury to any part of the structure by and 
 after the removal of the forms. 
 
 h. Comparison of dimensions of all parts of the finished struc- 
 ture with the plans. 
 
 Tests of 81. Samples of concrete shall be taken from the wheelbarrows as it 
 
 Concrete. 
 
 is being transported to the forms and tested in 8-in. cylinders, 16 in. 
 long, to ascertain the crushing strength, as directed by the engineer. 
 
41 
 
 82. All steel shall be tested before it is shipped from the mills, and 
 all manufactured steel work inspected in the shops where the work is 
 being done before shipment, as specified for structural steel work. 
 
 83. Load tests on portions of the finished structure shall be made 
 where there is reasonable suspicion that the work has not been 
 properly performed, or that, through influences of some kind, the 
 strength has been impaired. A test load of twice the live load shall 
 cause no permanent deformations. Load tests shall not be made until 
 after 60 days of hardening. 
 
 Tests of 
 Steel. 
 
 Load Tests. 
 
42 
 
 FORMULAS FOE APPROXIMATE COMPUTATIONS 
 
 RECOMMENDED BY THE GERMAN 
 
 CONCRETE ASSOCIATION. 
 
 SIMPLE BENDING. 
 1. Rectangular Beams. 
 (a) Reinforced for tension only (see Fig. 1). 
 
 If A 8 = total area of the reinforcement, in sq. in. 
 b . width of the beam in inches. 
 
 E. I 15 for stone concrete, 
 h = effective depth, n= ~ = j 30 for cinder concrete. 
 
 M = moment of the exterior forces, in inch-pounds. 
 V = total vertical shear, in pounds. 
 Distance of neutral axis from top of beam 
 
 x= - 
 
 Max. unit stress on concrete tf = 
 
 2 M 
 
 Unit stress on steel 6 = 
 
 bx(ji- 
 M 
 
 ^-1) 
 
 Unit shear 
 
43 
 
 Unit bond stress on the reinforcing bars 
 
 Sum of perimeters of all bars 
 
 A computation of the shear and bond for freely supported beams 
 is not generally necessary. 
 
 (b) With double reinforcement for tension and compression (see 
 Fig. 2). 
 
 The distance of neutral axis from top of beam 
 
 and the maximum unit compression on the concrete 
 
 6 MX 
 
 bx*(3hx)-\-6As n(x h')(h h') 
 Unit stress in tension in the lower reinforcement 
 
 Unit stress in compression on the upper reinforcement 
 
 2. Beams of T Section. 
 
 The effective width 6 of the slab is to be assumed as b ~^~ ^ Z, where I 
 denotes the effective length of the beam; b should, however, not be 
 larger than the distance between stems. 
 
 For T beams, two cases have to be considered: 
 
 (a) When the neutral axis lies in the slab, or x~^~ d (see Fig. 3). 
 
 The formulas for rectangular beams reinforced for tension also 
 apply to beams of T section when the shear in the stem and the bond 
 in the reinforcement over the supports have to be computed. 
 
44 
 
 (&) Where the neutral axis lies in the stem, or x > cl (see Fig. 4). 
 
 If we neglect the small compression in the stem of the beam, we 
 
 get: 
 
 2nhA s + bd 2 
 
 M 
 
 and 6 = - 
 
 n (ft x) 
 
 COMPEESSION. 
 
 Columns in which buckling need not be considered. 
 (a) Axial pressure. 
 
 If A c denotes the area of the concrete, the total safe load on the 
 column 
 
 P = <5 C (A c -f- n J. s ), where n = 15, 
 and 
 
 P P 
 
 (fc) Eccentric pressure (bending combined with axial pressure). 
 
 The computations can be made in the same manner as for sections 
 of homogeneous material if, in the areas and moments of resistance, 
 the section of the reinforcement is added to that of the concrete with 
 n = 15 times its value. If tensile strains occur, the steel reinforcement 
 on the tension side must be able to resist the same. 
 
45 
 
 APPENDIX. 
 
 TABLE 1. WEIGHTS OF BUILDING MATERIALS, ETC., IN POUNDS 
 PER CUBIC FOOT. 
 
 Material. Weight, 
 
 Brick, pressed and paving 150 
 
 " common building 120 
 
 " soft building 100 
 
 Granite 170 
 
 Marble 170 
 
 Limestone 160 
 
 Sandstone 150 
 
 Cinders 40 
 
 Slag 160-180 
 
 Granulated furnace-slag 53 
 
 Gravel . 120 
 
 Slate 175 
 
 Sand, clay and earth (dry) 100 
 
 " " " (moist) 120 
 
 Coal ashes 45 
 
 Paving asphaltum ' 100 
 
 Plaster of Paris , 140 
 
 Glass 160 
 
 Water 62 
 
 Snow, freshly fallen 10 
 
 ' wet 50 
 
 Spruce 25 
 
 Material. Weight. 
 
 Hemlock 25 
 
 White pine 25 
 
 Douglas fir 80 
 
 Yellow pine 40 
 
 White oak 50 
 
 Mortar 100 
 
 Stone concrete 150 
 
 Cinder " '. 110 
 
 Common brick work 100-120 
 
 Rubble masonry, sandstone 180 
 
 limestone 140 
 
 granite 150 
 
 Ashlar ' sandstone 140 
 
 limestone 150 
 
 granite 165 
 
 Masonry debris 90 
 
 Cast iron 450 
 
 Wrought iron 480 
 
 Steel 490 
 
 Lead 711 
 
 Copper, rolled 490 
 
 Plaster, ceiling. 10 to 15 Ib. per sq. ft. 
 
 TABLE 2. WEIGHTS OF MERCHANDISE, ETC., STORED LOOSE IN HEAPS 
 OR TANKS, IN POUNDS PER CUBIC FOOT. 
 
 Alcohol 52 
 
 Apples 47 
 
 Barley 40 
 
 Beans 55 
 
 Beets . , 40 
 
 Books 40 
 
 Canned Goods 45 
 
 Cement, natural 50-70 
 
 Portland ...90-100 
 
 Chalk 156 
 
 Charcoal 15-30 
 
 Cheese 30 
 
 Coal, soft 50 
 
 " hard.... 55 
 
 Coke 30-50 
 
 Cork 15 
 
 Corn 88 
 
 Cotton Goods 40 
 
 Fat 58 
 
 Flour 50 
 
 Gunpowder 60 
 
 Gypsum 60-70 
 
 Hay, loose. . . 5 
 
 " baled 20 
 
 Ice 55 
 
 Lard 59 
 
 Leather Goods... 20 
 
 Lime 60-80 
 
 Naphtha 50 
 
 Oats 30 
 
 Oils 55 
 
 Paper 35-60 
 
 Peat, dry, unpressed 20-30 
 
 Petroleum 55 
 
 Pitch 75 
 
 Potatoes 45 
 
 Pumice Stone 56 
 
 Rags 20-45 
 
 Rosin 68 
 
 Rubber Goods ...60-100 
 
 Salt, solid 134 
 
 " coarse 65 
 
 " fine table 80 
 
 Straw 10-20 
 
 Sugar 50 
 
 Sulphur 125 
 
 Tallow 59 
 
 Tar 75 
 
 Tin, cast 462 
 
 " in boxes 278 
 
 Wheat 50 
 
 Wines 62 
 
 Woolen Goods . . 25 
 
 If stored in bags, barrels, cases or boxes, multiply above given weights by 0.8, but 
 take outside rectangular dimensions. 
 
40 
 
 TABLE 3. PERMISSIBLE COMPRESSIVE STRESSES FOR STEEL, 
 
 P = Stress allowed in Ib. per sq. in. 
 I = Length in inches. 
 r = Least radius of gyration, in inches. 
 
 P = 16 000 70 I 
 
 I 
 
 r 
 
 P 
 
 I 
 r 
 
 P 
 
 I 
 r 
 
 P 
 
 I 
 r 
 
 P 
 
 28 
 
 14 000 
 
 60 
 
 11 800 
 
 92 
 
 9 560 
 
 124 
 
 7 820 
 
 80 
 
 13 900 
 
 62 
 
 11 660 
 
 94 
 
 9 420 
 
 126 
 
 7 180 
 
 32 
 
 13 760 
 
 64 
 
 11 520 
 
 96 
 
 9 280 
 
 128 
 
 7 040 
 
 34 
 
 13 620 
 
 66 
 
 11 380 
 
 98 
 
 9 140 
 
 180 
 
 6 9)0 
 
 36 
 
 13 480 
 
 68 
 
 11 240 
 
 100 
 
 9 000 
 
 132 
 
 6 760 
 
 38 
 
 13 340 
 
 70 
 
 11 100 
 
 102 
 
 8860 
 
 134 
 
 6 620 
 
 40 
 
 13 200 
 
 72 
 
 10960 
 
 104 
 
 8 720 
 
 136 
 
 6 480 
 
 42 
 
 13 060 
 
 74 
 
 10 820 
 
 106 
 
 8 580 
 
 138 
 
 6 340 
 
 44 
 
 12 920 
 
 76 
 
 10680 
 
 108 
 
 8 440 
 
 140 
 
 6 200 
 
 46 
 
 12780 
 
 78 
 
 10 540 
 
 110 
 
 8 300 
 
 142 
 
 6 060 
 
 48 
 
 12 640 
 
 80 
 
 10400 
 
 112 
 
 8 160 
 
 144 
 
 5 920 
 
 50 
 
 12500 
 
 82 
 
 10 260 
 
 114 
 
 8 020 
 
 146 
 
 5 780 
 
 52 
 
 12 860 
 
 84 
 
 10 120 
 
 116 
 
 7 880 
 
 148 
 
 5 640 
 
 54 
 
 12220 
 
 86 
 
 9 980 
 
 118 
 
 7 740 
 
 150 
 
 5 500 
 
 56 
 
 12 080 
 
 88 
 
 9840 
 
 120 
 
 7 600 
 
 
 
 58 
 
 11 940 
 
 90 
 
 9 700 
 
 122 
 
 7 460 
 
 
 
47 
 
 R 
 
 a aiss 
 
 O TH CO 
 
 o co t- 
 
 10 J> 05 
 
 .2 3* 
 
 ^ r.s 
 
 
 
 o d d o d TH 
 
 ^, 
 
48 
 
 TABLE 5. MAXIMUM BENDING MOMENTS ON PINS. 
 Extreme Fiber Stress of 24000 Lb. per Sq. In. 
 
 Dia. of pin, 
 in inches. 
 
 Area of pin, 
 in sq. in. 
 
 Moments, in 
 inch-pounds. 
 
 Dia. of pin, 
 in inches. 
 
 Area of pin, 
 in sq. in. 
 
 Moments, in 
 inch-pounds. 
 
 2 
 
 8.142 
 
 18 850 
 
 6 
 
 33.183 
 
 647 070 
 
 
 3.547 
 
 22 610 
 
 6| 
 
 34.472 
 
 685 120 
 
 2 
 
 3.976 
 
 26 840 
 
 63 
 
 35.785 
 
 724 640 
 
 2jj 
 
 4.430 
 
 31 560 
 
 6g 
 
 37.122 
 
 765650 
 
 2i 
 
 4.909 
 
 86 820 
 
 7 
 
 38.485 
 
 808 170 
 
 2| 
 
 5.412 
 
 42 620 
 
 7 
 
 39.871 
 
 852 250 
 
 2? 
 
 5.940 
 
 49 000 
 
 ?s 
 
 41.282 
 
 897 890 
 
 2| 
 
 6.492 
 
 55 990 
 
 7| 
 
 42.718 
 
 945 140 
 
 3 
 
 7.069 
 
 63 620 
 
 7i 
 
 44.179 
 
 994 020 
 
 BJ 
 
 
 7.670 
 
 71 910 
 
 71 
 
 45.664 
 
 1 044 550 
 
 3 
 
 
 8.296 
 
 80 880 
 
 7! 
 
 47.173 
 
 1 096 770 
 
 3 
 
 
 8.946 
 
 90 580 
 
 7 7 
 
 48.707 
 
 1 150 700 
 
 3 
 
 
 9.621 
 
 101 020 
 
 8 
 
 50.265 
 
 1 206 370 
 
 8 
 
 
 10.321 
 
 112 240 
 
 8 
 
 51.849 
 
 1 263 810 
 
 3 
 
 
 11.045 
 
 124 250 
 
 8 
 
 
 53.456 
 
 1 3*3 040 
 
 3 
 
 
 11.793 
 
 137 100 
 
 i 
 
 
 55.088 
 
 1 384 090 
 
 4 
 
 
 12.566 
 
 150 800 
 
 I 
 
 
 56.745 
 
 1 447 000 
 
 i 
 
 
 13.364 
 
 165 380 
 
 8: 
 
 
 58.426 
 
 1 511 780 
 
 4 
 
 
 14.186 
 
 180 870 
 
 8 
 
 
 60.132 
 
 1 578 470 
 
 4, 
 
 
 15.033 
 
 197 310 
 
 8; 
 
 
 61.862 
 
 1 647 080 
 
 4i 
 
 
 15.904 
 
 214 710 
 
 9 
 
 63.617 
 
 1 717 660 
 
 4 
 
 
 16.800 
 
 233 100 
 
 9 
 
 65.397 
 
 1 790 230 
 
 1 
 
 
 17.721 
 
 252 520 
 
 ! 
 
 
 67.201 
 
 1 864 820 
 
 4 
 
 
 18.665 
 
 272 980 
 
 9i 
 
 
 69.029 
 
 1 941 360 
 
 5 
 
 19.635 
 
 294 520 
 
 9 
 
 
 70.882 
 
 2 020 140 
 
 
 20.629 
 
 317 170 , 
 
 9; 
 
 
 72.760 
 
 2 100 940 
 
 51 
 
 21.648 
 
 340 950 
 
 8 
 
 
 74.662 
 
 2 183 860 
 
 5| 
 
 22.691 
 
 365 890 
 
 9 
 
 ' 
 
 76.590 
 
 2 268 940 
 
 H 
 
 23.758 
 
 392 010 
 
 10 
 
 78.54 
 
 2 356 190 
 
 si 
 
 24.850 
 
 419 350 
 
 10 
 
 82.52 
 
 2 537 360 
 
 s| 
 
 25.967 
 
 447 930 
 
 io| 
 
 86.59 
 
 2 727 590 
 
 si 
 
 27.109 
 
 47? 790 
 
 10! 
 
 90.76 
 
 2 927 090 
 
 6 
 
 28.274 
 
 508 940 
 
 11 
 
 95.03 
 
 3 136 090 
 
 1 
 
 29.465 
 30.680 
 
 541 410 
 575 240 
 
 11* 
 "I 
 
 99.40 
 103.87 
 
 3 354 810 
 3 583 480 
 
 6f 
 
 31.919 
 
 610 450 
 
 12 
 
 113.10 
 
 4 071 500 
 
 TABLE 6. THICKNESS OF SPRUCE AND WHITE PINE PLANK 
 FOR FLOORS. 
 
 THICKNESS OF PLANK IN INCHES FOR VARIOUS LOADS PER SQ. FT. 
 
 Span in feet. 
 
 lb. 
 
 30 
 
 lb. 
 
 40 
 
 lb. 
 
 50 
 
 lb. 
 
 75 
 
 lb. 
 
 100 
 
 lb 
 
 19.5 
 
 lb. 
 
 150 
 
 lb. 
 
 175 
 
 lb. 
 
 200 
 
 lb. 
 225 
 
 lb. 
 
 250 
 
 lb. 
 275 
 
 lb. 
 
 300 
 
 lb. 
 325 
 
 lb. 
 
 350 
 
 lb. 
 
 375 
 
 lb. 
 
 400 
 
 4 
 5 
 
 0.9 
 
 1 9 
 
 1.1 
 1 4 
 
 1.2 
 1 5 
 
 1.5 
 
 1 8 
 
 1.7 
 9, 1 
 
 1.9 
 
 9 4 
 
 2.1 
 9, 6 
 
 2.2 
 
 9, 8 
 
 1.4 
 3 
 
 2.5 
 3 9 
 
 2.7 
 3 4 
 
 2.8 
 3 5 
 
 2.9 
 
 3 7 
 
 3.1 
 
 3 8 
 
 3.2 
 4 1) 
 
 3.3 
 <\ 1 
 
 3.4 
 4 8 
 
 6 
 
 7 
 
 1.4 
 1 7 
 
 1.6 
 1 9 
 
 1.8 
 9 1 
 
 2.2 
 9, 6 
 
 2.6 
 3 
 
 2.9 
 3 3 
 
 3.1 
 
 3 7 
 
 3.4 
 3 9 
 
 3.6 
 4 9 
 
 3.8 
 4 5 
 
 4.0 
 4 7 
 
 4.2 
 4 9 
 
 4.4 
 5 9, 
 
 4.6 
 5 4 
 
 4.8 
 * fi 
 
 4.9 
 
 5 8 
 
 5.1 
 
 5.9 
 
 8 
 9 
 
 1.9 
 9, 1 
 
 2.2 
 
 9, 5 
 
 2 4 
 
 9 7 
 
 3.0 
 3 4 
 
 3.4 
 3 9 
 
 3.8 
 4 3 
 
 4.2 
 
 4 7 
 
 4.5 
 5 1 
 
 4.8 
 5 4 
 
 5.1 
 
 5 8 
 
 5.4 
 6 1 
 
 5.7 
 
 5.9 
 
 6.1 
 
 
 .... 
 
 
 10 
 
 9 4 
 
 9 7 
 
 3 1 
 
 3 7 
 
 4 3 
 
 4 8 
 
 "i 9, 
 
 *) ) 
 
 6 
 
 
 
 
 
 
 
 
 
 11 
 
 9, 6 
 
 3 
 
 3 4 
 
 4 1 
 
 4 7 
 
 5 3 
 
 5 8 
 
 
 
 
 
 
 
 
 
 
 
 12 
 
 9 9 
 
 3 8 
 
 3 7 
 
 4 5 
 
 5 9 
 
 
 
 
 
 
 
 
 
 
 
 
 
 13 
 
 3 1 
 
 3.6 
 
 4 
 
 4 9 
 
 5 6 
 
 
 
 
 
 
 
 
 
 
 ... 
 
 
 
 14 
 
 3 4 
 
 3 9 
 
 4 3 
 
 5 3 
 
 6 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 For Yellow Pine use nine-tenths of the above thickness. 
 
40 
 
 TA>LEI 7 
 
 STANDARD DIMENSIONS TOR COLUMNS 
 
 in 
 
 \ 5k 
 
 Sfe 
 
 A 
 
 a 
 
 (p 
 
 6k" 
 
 
 a 
 
 16 
 
 15'CHANNELGOLUMNS 
 
 WITH 
 
 4 I 4 
 
 14" 
 
 e"CHANNEL COLUMNS 
 
 WITH 14 <$IG Cov. Pi_e>. 
 
 Q 
 
 ^ 
 
 i 
 
 12" 
 
 IO"CHANNEL COLUMNS 
 
 WlTHl2"<&l4CcV.Fls. 
 
 c 
 
 12" 
 
 r 
 
 12 
 
 oo 
 
 10" 
 
 s 
 
 p 
 b 
 
 _ 
 10 
 
 9"CHANNELGOLUMNe> 
 
 WITH ioX 12 Cov. PLS. 
 
 la BE USED ONLYWHEM 
 UNAVOIDABLE 
 
 'CHANNEL COLUMNS 
 
 WITH id ,5 Cov.F\.e>. 
 
 PLATE 3 ANGLE 
 COLUMNS 
 
50 
 
 TABLE 8 
 
 STANDARD FRAMING OF BEAMS 
 
 2,4" 
 
 
 
 IS" 
 
 WEIGHT 41 LBS. 
 
 2. LS 4*4x^x1-3" 
 WEIGHT 34L-B3. 
 
 15 
 
 WEIGHT 29 LB&. 
 
 WEIGHT 2aLsa WEIGHT 15 LBS 
 
 e" 
 
 WEIGHT 
 
 21*6*4*^x0-2" 
 
 WEIGHT <s LBS 
 
 AMERICAN BRIDGE . Co. STANDARD CAST IRON SEPARATORS 
 
 .c.. 
 
 ft)R6TDIOl9 
 
 SIZE 
 
 IHCHES 
 
 20 
 
 WEIGHT 
 
 PERFt. 
 
 Fbuwos 
 
 80 
 
 65 
 
 55 
 
 42 
 
 25 
 
 21 
 
 18 
 
 15 
 
 !2'/4 
 
 6 
 
 OufTbOi/r 
 -FLAMOES 
 
 INCHES 
 
 15 
 
 II 
 
 10 
 
 AND BOOS 
 
 ICTAL 
 
 52.3 
 
 24.2 
 
 15.0 
 
 11.9 
 
 8.4 
 
 6.3 
 
 5.2 
 
 5.2 
 
 5.2 
 
 NCREA5E|n 
 
 WEIGHT OF 
 
 SCPARATOP 
 
 BEAM 
 
 DISTANCE 
 
 C.ToC. 
 OFBEAM5 
 
 3.6 
 
 2.9 
 
 2.5 
 
 .6 
 
 1.3 
 
 6 
 
 .9 
 
 .7 
 
 10 
 
 II 
 
 WEIGHT 
 OFRPE: 
 AND BOLT 
 
 i. a 
 
 1.4 
 
 1.9 
 
 2.2, 
 
 2.5 
 
 2.7 
 
 3.2 
 
 3.5 
 
 CAST WA5HER5 
 
 13 
 
 4.0 
 
 BOLT 
 
 D. 
 
 WEIGHT 
 
 4.2. 
 
 .41 
 
 4.0 
 
 IS 
 
 5.3 
 
 .o 
 
 WEIGHTS GIVEN ARE FOR 
 
 !'* PIPE. AND ^BoiT 
 
51 
 
 STANDARD DETAILS 
 
 GOVERNMENT ANCHOR 
 
 WEIGHT 5 s ** 1 
 
 ANGLE ANCHOR 
 
 -y 
 
 ANGLES 
 SHIPPED LOOSE 
 
 2 
 
 I BOLT W+ 
 
 WEIGHT WITH DOLT/* 
 
 BUILT IN ANCHOR BOLTS 
 
 SWEDGE: Bocre 
 
 WHEN DOLTS ARE^ER^RATED LESS THAN 
 
 WlDTHOFWtfhER USE DASHER WmiTWO HOLES 
 
 DAM 
 INCHES 
 
 LENGTH 
 Pn^lwa 
 
 WEIGHT 
 
 NCLUPING 
 
 NUT- Lea 
 
 
 
 c 
 
 2 
 
 % 
 
 l'-o" 
 
 3 
 
 1 
 
 l-o" 
 
 4- 
 
 [5 
 
 I 1 - 3" 
 
 7 
 
 PURLIN CONNECTIONS 
 
 ANGLE RJRLI MS 
 
 LEQH 
 
 2x2. 
 
 3x2^2 
 
 GLIPAGLC 
 
 4x5 
 4x3 
 
 ^ 'e'^io" CHANNELS 
 ] 15 HAVE FLANGE ALSO 
 ArrACHEDlb RAFTERS 
 
 I I 
 
52 
 
 TABLE 10. PLATE GIRDERS. 
 Tension 16 000 Lb. per Sq. In. Net. Area. 
 
 Each flange 2 angles. 
 
 Web plate. 
 
 Weight per ft. 
 
 Maximum 
 moments, thou- 
 sands of ft. Ibs. 
 
 3 X 2 X A 
 
 24 X i 
 
 38 4 
 
 90 
 
 31 V 24- X i . 
 
 24 X i 
 
 40 
 
 99 
 
 31 X 2A X 5 
 
 SOX I 
 30 X 
 
 45.1 
 49 9 
 
 132 
 
 154 
 
 4 x 3 X A . 
 
 ' 30 X 
 
 54 3 
 
 177 
 
 5 X 3 1 X -t 
 
 36 X ] 
 36 X 
 
 59.4 
 65 4 
 
 222 
 265 
 
 5 X 3 X f 
 
 42 X i 
 36 X ^ 
 
 70.5 
 79 8 
 
 320 
 318 
 
 6 X 4 X 
 
 42 X A 
 
 48 X A 
 36 X A 
 
 86.2 
 92.6 
 
 87 4 
 
 385 
 457 
 367 
 
 6 X 4 X X 
 
 42 X A 
 48. X A 
 36 X T 5 
 
 93.8 
 100.2 
 95 4 
 
 443 
 524 
 415 
 
 \J S\ 1 S\ Y^r . 
 
 6 X 4 X i 
 
 42 X A 
 48 X A 
 36 X A 
 
 101.8 
 108.2 
 103.0 
 
 500 
 589 
 462 
 
 6 X 4 X | 
 
 42 X A 
 48 X A 
 
 60 X A 
 36 X 3 
 
 109.4 
 115.8 
 
 128.6 
 125 9 
 
 555 
 652 
 
 856 
 565 
 
 6 X X 
 
 42 X } 
 
 48 X f 
 60 X f 
 36 X f 
 
 133.6 
 141.2 
 156.6 
 124 3 
 
 679 
 797 
 1 046 
 544 
 
 6X6X| 
 
 48 X | 
 60 X f 
 36 X * 
 
 139.6 
 155.0 
 142 7 
 
 774 
 1 023 
 652 
 
 6 X 6 X a 
 
 48 X f 
 60 X | 
 36 X f 
 
 158.0 
 173.4 
 176 
 
 923 
 1 211 
 
 781 
 
 
 48 X f 
 60 X | 
 
 72 X | 
 
 176.0 
 191.4 
 206.6 
 
 1 066 
 1 393 
 1 739 
 
53 
 
 TABLE 11. WEIGHTS OF KOOF TRUSSES AND PURLINS FOR 
 
 UNIFORM LOADINGS. 
 Weight of Trusses. 
 
 PL 
 
 W 
 
 300 + 6 L + 
 
 P D 
 
 in which 
 
 W = weight of truss per square foot of building; 
 
 L = span of truss in feet; 
 
 D = distance center to center of trusses in feet; 
 
 P = load per square foot on truss. 
 Weight of Purlins. 
 
 D 1 
 
 45 4 ' 
 
 in which 
 
 W l = weight of purlins per square foot of building; 
 D = distance center to center of trusses in feet; 
 P 1 = load per square foot on purlins. 
 
 TABLE 12. TYPICAL HAND CRANES. 
 
 Capacity 
 in tons. 
 
 Span. 
 
 Wheel base. 
 
 Maximum 
 wheel 
 load in 
 pounds. 
 
 Side 
 clear- 
 ance. 
 
 Vertical 
 clearance. 
 
 WEIGHT OP RAIL POR: 
 
 Plate Girders. 
 
 Beams. 
 
 2 
 
 30 
 50 
 
 4 ft. in. 
 5 " kl 
 
 3100 
 4000 
 
 7 in. 
 
 7 k - 
 
 4 ft. in. 
 
 4 ' kk 
 
 30 Ibs. per yd. 
 
 30 u 
 
 30 
 30 
 
 4 
 
 30 
 50 
 
 4 " " 
 5 " " 
 
 5400 
 6500 
 
 8 " 
 8 " 
 
 4 " 6 ' 
 
 4 " " 
 
 30 
 30 
 
 80 
 30 
 
 6 
 
 30 
 50 
 
 6 kl " 
 
 7 " " 
 
 8000 
 9200 
 
 9 * 
 9 " 
 
 5 ft. " 
 
 5 kk " 
 
 35 
 
 35 " 
 
 80 
 
 80 
 
 8 
 
 30 
 50 
 
 6 " 
 
 7 " " 
 
 10500 
 11800 
 
 10 " 
 10 " 
 
 5 " " 
 5 " " 
 
 40 ' 
 40 
 
 35 
 35 
 
 10 
 
 30 
 
 50 
 
 7 " " 
 8 " " 
 
 13000 
 14400 
 
 10 " 
 10 " 
 
 5 kk " 
 
 5 " 6 " 
 
 40 
 40 
 
 40 
 40 
 
 16 
 
 30 
 50 
 
 7 k " 
 8 k " 
 
 20700 
 22300 
 
 10 " 
 10 " 
 
 5 " 6 " 
 5 k " 6 " 
 
 45 " 
 45 
 
 45 
 45 
 
 20 
 
 30 
 50 
 
 7 ' " 
 8 ' " 
 
 26000 
 28000 
 
 10 " 
 10 ik 
 
 5 kk 6 " 
 5 kl 6 tk 
 
 50 " 
 50 
 
 50 
 50 
 
 25 
 
 30 
 50 
 
 7 ' " 
 8 ' kk 
 
 82300 
 35000 
 
 12 " 
 12 kt 
 
 6 k ' ' 
 6 " ' 
 
 55 " 
 55 
 
 50 
 
 50 
 
54 
 
 TABLE 13. TYPICAL ELECTRIC TRAVELING CRANES. 
 
 Capacity, 
 in tons. 
 
 i 
 
 Wheel base. 
 
 (j o 
 
 Maximum 
 wheel load, 
 in pounds. 
 
 Side 
 clearance. 
 
 Vertical 
 clearance. 
 
 WEIGHT OF RAIL FOR : 
 
 Plate girders. 
 
 Beams. 
 
 5 
 10 
 16 
 
 23 
 25 
 
 30 
 40 
 50 
 60 
 
 60 
 75 
 100 
 150 
 
 40 
 60 
 
 40 
 60 
 
 40 
 60 
 
 40 
 60 
 
 40 
 60 
 
 40 
 60 
 
 40 
 60 
 
 40 
 60 
 
 40 
 60 
 
 80 
 
 40 
 60 
 
 80 
 40 
 60 
 
 80 
 40 
 60 
 
 80 
 40 
 60 
 
 80 
 
 8 ft. 6 in. 
 
 9 " " 
 
 9 " " 
 9 tk 6 " 
 
 9 " 6 " 
 10 " " 
 
 10 " " 
 10 " 6 " 
 
 10 " " 
 
 10 " 6 " 
 
 10 " 6 " 
 11 " " 
 
 11 " " 
 
 12 " " 
 
 11 " " 
 
 12 " " 
 
 13 " " 
 14 " " 
 15 " " 
 
 12 000 
 18 000 
 
 19 000 
 21 000 
 
 25 000 
 29 000 
 
 33 000 
 36 000 
 
 40 000 
 44 000 
 
 48 000 
 52 000 
 
 64 000 
 70000 
 
 72 000 
 80 000 
 
 88 000 
 94 000 
 108 000 
 
 44 000 
 
 47 000 
 
 51 500 
 55 000 
 60 000 
 
 64 000 
 83 000 
 86 000 
 
 89 000- 
 130 000 
 134 000 
 
 139 000 
 
 10 in. 
 
 10 " 
 
 10 " 
 
 10 " 
 
 10 ' 
 10 " 
 
 12 " 
 12 " 
 
 12 " 
 12 " 
 
 12 ' 
 12 " 
 
 12 " 
 12 " 
 
 14 " 
 14 " 
 
 16 " 
 16 " 
 
 16 ' 
 
 16 t; 
 16 " 
 
 16 " 
 
 16 " 
 16 " 
 
 16 " 
 19 " 
 
 19 " 
 
 19 " 
 
 20 ' 
 20 ' 
 
 20 " 
 
 6 ft. in. 
 
 6 " " 
 
 6 " " 
 
 6 " k ' 
 
 7 " tk 
 7 " " 
 
 7 " " 
 7 " " 
 
 8 u " 
 
 8 " " 
 
 8 " " 
 8 " " 
 
 9 " " 
 
 9 " " 
 
 9 " " 
 9 " -" 
 
 9 " t; 
 9 " " 
 9 u " 
 
 10 " 6 ' k 
 10 u 6 " 
 
 10 " 6 " 
 12, " " 
 12 " " 
 
 12 " ' 
 13 " 6 lk 
 13 " 6 " 
 
 13 ' 6 " 
 
 16 " " 
 16 " " 
 
 16 " lk 
 
 40 Ib. per yd. 
 
 40 " 
 
 45 
 45 
 
 50 
 50 
 
 55 
 55 
 
 60 
 60 
 
 70 " 
 70 " . 
 
 80 " 
 80 
 
 100 
 109 
 
 100 
 100 
 100 
 
 100 " 
 100 
 
 100 
 100 
 100 
 
 100 " 
 100 
 100 " 
 
 100 
 150 " 
 150 
 
 150 
 
 40 
 40 
 
 40 
 40 
 
 50 
 50 
 
 50 
 50 
 
 50 
 50 
 
 60 
 60 
 
 60 
 60 
 
 60 
 60 
 
 
 
 
 M&A 
 
 
 
 
 miim 
 
 
 soeoac' 
 
 
 -14L$ lL 
 
 
 
 tieteo 
 
 
 
 
 SUUUL 
 
 
 M- 
 
 
 
 
 
 
 Loads, clearances, etc., given above are for end carriages of electric cranes. 
 
55 
 
 ABSTRACTS FROM THE FOLLOWING BUILDING LAWS: 
 City Year. 
 
 New York 1906 
 
 Chicago 1905 
 
 Philadelphia 1907 
 
 Baltimore 1908 
 
 St. Louis 1907 
 
 Boston 1907 
 
 Buffalo 1905 
 
 San Francisco 1907 
 
 Milwaukee 1901 
 
 District of Columbia 1902 
 
 Minneapolis 1907 
 
 Providence 1905 
 
 Kochester 1904 
 
 New Haven 1905 
 
 In the following tables: 
 
 I = Unsupported length, in inches ; 
 Z x = Effective " " 
 
 r = Corresponding radius of gyration, in inches; 
 d = Least lateral dimension, in inches; 
 W = Total load, in lb., uniformly distributed. 
 
56 
 
 TABLE 
 MINIMUM LIVE LOADS FOR 
 
 
 
 
 
 
 ] 
 
 POUNDS PER 
 
 Structure. 
 
 New York, 
 1906. 
 
 Chicago, 
 1905. 
 
 Philadelphia 
 
 1907. 
 
 Baltimore, 
 1908. 
 
 .3 
 
 | 
 
 
 
 fr 
 
 Dwellings, apartment houses, I 
 hotels etc f 
 
 .) 
 
 Dwellings, 
 apartment 
 houses, 40 ; 
 
 } 70 
 
 60 
 
 60 j 
 
 50 
 For room 
 > 500 
 
 Office buildings first floor 
 
 1 
 I 
 
 150 
 
 hotels, 
 etc., 50. 
 
 50 
 
 J 
 
 ioo 
 
 150 
 
 I 
 150 
 
 sq. ft., 100. 
 100 
 
 Office buildings, above first floor 
 
 Public assembly rooms, churches, I 
 theatres etc I 
 
 75 
 90 
 
 50 
 100 
 
 100 
 120 \ 
 
 75 
 
 75 with, 
 125 with- 
 out fixed 
 
 70 
 
 lioo 
 
 100 
 200 
 
 Schools or places of instruction 
 
 75 
 
 75 
 
 ( 
 
 seats. 
 75 
 
 J 
 100 -{ 
 
 Assembly 
 rooms, 125; 
 
 Machine shops, armories, drill- 1 
 
 
 
 
 
 ( 
 
 other 
 rooms, 60. 
 
 rooms, etc C 
 
 Light manufacturing and retail j 
 stores and storehouses ] 
 
 120, not 
 includ 
 
 1- 100 
 
 120 
 
 125 
 
 150 
 
 125 
 
 Heavy storehouses, warehouses and J 
 
 chinery. 
 
 150, not 
 includ- 
 
 I 100 
 
 150 { 
 
 Factory, 
 175 ; 
 storage, 
 
 f-150 
 
 . 
 250 
 
 Stables or carriage houses 
 
 chinery. 
 
 *'l 
 
 J 
 
 Area < 500 
 sq. ft., 40; 
 
 ( 
 \ 
 
 100 
 
 j 
 
 
 Stairways 
 
 [ 
 
 larger 
 floors, 100. 
 
 
 
 
 70 
 
 Sidewalks 
 
 300 
 
 
 
 200 
 
 
 
 Roofs, per square foot of super- j 
 
 For 
 
 slopes 
 
 j 
 
 30 
 
 
 
 
 Roofs, per square foot of horizontal j 
 
 < 20, 50. 
 
 For 
 
 slopes 
 
 1 
 
 I 2 5 
 
 I 
 
 For 
 slopes 
 
 > 90 20 
 
 1 For 
 1 flat 
 
 (For flat 
 
 Wind, per square foot of elevation.. . 
 
 > 20, 30. 
 
 *\ 
 
 j 
 
 When \ 
 h't is j 
 
 1 
 
 35, re- 
 duced. 
 See Build- 
 
 <20, 40. 
 
 u 
 
 J 40. 
 30 
 
 
 
 { 
 
 = li 1 
 width, 30. [ 
 
 ing Laws, 
 pp. 32-33. 
 
 1 
 
 
 

 67 
 
 14 A. 
 
 FLOORS, ROOFS, AND WALLS. 
 
 SQUARE FOOT. 
 
 
 - 
 
 8 
 
 
 .22 
 
 6 
 
 
 .. 
 
 of 
 
 fr 
 
 iji 
 
 
 
 & . 
 
 II 
 
 
 
 II" 
 
 Minneapol 
 
 1907. 
 
 3g 
 
 
 
 1 
 
 S I 
 
 t 
 
 c3io 
 
 Kg 
 fc 1 ^ 
 
 0) 
 
 fc 
 
 Id 
 
 is 
 
 Dwellings, 
 40 ; apart 
 houses, ho- 
 tels, etc., 70 
 
 ] First floo 
 \ 150 ; othe 
 floors, 75. 
 
 L 40 
 
 Halls, dining 
 rooms, offices 
 etc., 75; other 
 rooms, 50. 
 
 j- 
 
 f70ex 
 
 } 
 
 7 
 
 ( 40 * 
 
 <8 000 t 
 I 500 t 
 
 
 
 
 Halls and ] 
 
 
 
 
 
 
 70 
 
 150 
 
 60 
 
 Lobbies. 110; 
 other floor 
 
 If. 
 
 150 
 
 70 
 
 IOC 
 
 ( 80 * 
 {5 000 t 
 
 
 
 
 space, 75. j 
 
 
 
 
 
 (tooo j 
 
 70 
 
 75 
 
 60 
 
 do. 
 
 7 
 
 150 
 
 70 
 
 IOC 
 
 ( 50 * 
 
 <5 000 t 
 
 
 
 
 
 
 
 
 
 |l 000 t 
 
 100 
 
 125 
 
 80 
 
 110 
 
 125 
 
 125^ 
 
 Theaters, ) 
 
 80 
 
 120 
 
 ( 100 * 
 {5 000 t 
 
 
 
 
 
 
 | 
 
 others, 70 \ 
 
 
 (l 000 % 
 
 )100 
 
 75 
 
 50 
 
 75 
 
 100 
 
 100 
 
 70 
 
 7 
 
 ( 60 * 
 J5 000 t 
 
 
 
 
 
 
 
 
 
 |l 000 $ 
 
 
 
 250 
 
 
 
 250 
 
 
 
 
 120 
 
 120 ; not in- 
 cluding ma- 
 chinery. 
 
 > 100 
 
 1 
 
 110 
 
 100 
 
 150 
 
 100 
 
 150 
 
 ( 80 * 
 
 -(8 000 t 
 |l 000 J 
 
 150 
 
 250 ; not in 
 eluding ma- 
 
 1 
 
 200 
 
 
 j 
 
 150; in- 1 
 
 
 ( 120up * 
 
 
 chinery. 
 
 
 
 
 50j 
 
 crease for > 
 machinery- ) 
 
 
 < special t 
 (special t 
 
 j Public, 120; i 
 
 n* 
 
 
 
 
 ( 
 
 Pnhlio 100 
 
 
 ( 80 * 
 
 1 Private, 40. j 
 
 75 
 
 
 200 
 
 85 
 
 70] 
 
 c UOJ1C, 1UU , 
 
 Private, 50. 
 
 
 -{8 000 j- 
 (l 000 J 
 
 
 r 
 
 100 ; lower 
 
 
 
 
 
 
 
 
 i 
 .; 
 
 supports to 
 carry two- 
 
 
 
 
 
 
 
 
 i 
 
 t birds of 
 
 
 
 
 
 
 
 
 i 
 
 total wt, 
 
 
 
 
 
 
 
 
 300 
 
 
 
 SOO 
 
 
 
 
 ( 800 * 
 J jo 000 t 
 
 
 
 
 
 
 
 
 
 I 1 000 % 
 
 I 
 
 "or slopes I 
 
 30 
 
 25 
 
 
 50 
 
 
 40 
 
 Flat roofs. 
 
 i 
 
 < 20, 50. ( 
 
 
 
 
 
 
 
 40 * 
 
 
 
 
 
 
 
 
 
 2 000 t 
 
 
 
 
 
 
 
 
 
 500 J 
 
 f ^O \ 
 
 "or slopes 1 
 
 
 
 30 
 
 
 40 
 
 
 slopes, 
 
 
 < 20, 30. f 
 
 
 
 
 
 
 
 special. 
 
 
 r 
 
 JO at twelfth 
 
 
 
 
 
 
 
 , When h't is 
 
 
 jory. 
 
 
 
 
 
 
 
 = H width, 
 
 90 4 
 
 > less at 
 
 30 
 
 
 
 30 
 
 
 30 
 
 30 2 
 
 \ 
 
 ich lower 
 
 
 
 
 
 
 
 
 ( 
 
 tory. 
 
 
 
 
 
 
 
 * Uniform load in pounds per square foot of floor area. 
 
 t Concentrated load in pounds, which shall be applied to any point of the floor. 
 
 J Uniform load, in pounds per linear foot, for girders. 
 
O PH 
 
 O O 
 
 rv. EH 
 
 - CO 
 
 58 
 
 
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 H H 
 
 9 o 
 
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59 
 
 neid 
 1910. 
 
 more, 
 08. 
 
 delphia, 
 907. 
 
 *". 
 
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 fa 
 
 = i^! . 
 
 
 
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 !!!!=!!! 
 
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 ed 
 
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 JTOS AUB aoj ranuiixBiu 
 
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 S? * * 
 
 CC 05 
 
 
 
 
 S06I 
 
 sr 
 
 
 
 
 
 
 
 
 
 . . 
 
 Jc 
 
 ; 3[JOi M9JJ 
 
 - 
 
 
 V M 
 
 Tf 
 
 
 
 Bearing material. 
 
 
 
 : : : : 
 
 d : 
 
 ^ 
 
 :'* : :s 
 
 Dressed foundation stones, in ce 
 
 j 
 
 9 
 
 
 
 ! Ill 
 
 li 
 
 Gravel and sand (well cement 
 Firm, coarse sand and gravel 
 Concrete in foundations 
 
 Soft clay 
 
 rr-v olav 
 
 t 
 
 '1 
 
 i 
 
 1 Ml |li 
 2 11s i!S 
 
 Ml| III! 
 
 isi^!^i&; 
 
 JfiWOOiJ QK^C 
 
61 
 
 3 
 
 sa s 
 
 H O 
 
 '0161 
 
 S061 
 
 '1061 
 
 \i06t 
 
 'OOSIOITBJ jj UBS 
 
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