American Society of Municipal Improvements, 1915 SPECIFICATIONS FOR Bituminous Concrete with One Pro duct of Stone Crushing Plant ADOPTED OCTOBER 14, 1915 These specifications will be modified from time to time to keep them fully up to date. Suggestions as to modifications or additions are solicited and should be sent to the Secretary, or to A. H. Blanchard, Columbia University, New- port City, Chairman of the Sub- Committee on Specifications for Broken Stone and Gravel Roads, and GEORGE W. TILLSON Boro Hall, Brooklyn, New York Chairman of General Committee on Standard Specifications COPYRIGHTED, 1916 -;.; ' Any municipality which is represented in the membership of the Society by one or more city officials, will be given free permission to use these specifications or any part of them upon application to the Secretary PUBLISHED BY THE SOCIETY CHARLES CARROLL BROWN, Secretary 702 WULSIN BUILDING INDIANAPOLIS, INDIANA SPECIFICATIONS FOR A BITUMINOUS CONCRETE PAVEMENT MINERAL AGGREGATE COMPOSED OF ONE PRODUCT OF A STONE CRUSHING PLANT. General Description. The bituminous concrete wearing course shall consist of a compact mixture of broken stone and asphalt cement or refined tar laid to conform to the required grades and cross sections, covered with a seal coat of asphalt cement and broken stone chips, and constructed as hereinafter specified. Broken Stone. Quality. All broken stone shall be clean, rough surfaced and sharp angled, of compact texture and uniform grain. Tests. The broken stone shall be subjected to abrasion and toughness tests conducted by the engineer in accordance with methods adopted by the American Society for Testing Materials, August 15, 1908. The broken stone used for the construction of the wearing course shall show a loss on abrasion of not more than 3.5 per cent or a French coefficient of wear of not less than 11.5, and its toughness shall not be less than 13.0. Broken Stone Chips. Broken stone chips shall consist of the product of a stone crushing plant obtained by passing the broken stone through a section of a rotary screen having circular openings three-eighths (%) or one-half ( l />} inch in diameter and over a screen having openings of one-eighth (%) or one-quarter (%) inch. Broken Stone for Mineral Aggregate. Broken stone for the mineral aggregate of the wearing course shall consist of one product of a stone crushing and screening plant. It shall conform to the following mechanical analysis, using laboratory screens having cir- cular openings: All of the broken stone shall pa^s a one and one- quarter (1^4) inch screen; not more than ten (10) per cent nor less than one (1) per cent shall be retained upon a one (1) inch screen; not more than ten (10) per cent nor less than three (3) per cent shall pass a one-quarter ( Vj ) mc h screen. 342939 Heating. Before entering the mixer, the broken stone for the mineral aggregate shall be heated until thoroly dry to between 66 C. (150 F.) and 121 C. (250 F.), as directed, in revolv- ing driers in which no flame shall be permitted to come in contact with the broken stone and in which the broken stone shall be con- tinuously agitated during the heating. Bituminous Cement. Asphalt Cement and Refined Tar. The asphalt cement or refined tar used in the construction of the wearing course of the bituminous concrete pavement shall conform with either one of the specifica- tions covering the chemical and physical properties of bituminous cement included under the item entitled "Asphalt Cements and Re- fined Tars for Wearing Course of Bituminous Concrete Pavement." If asphalt cement is used in the bituminous concrete wearing course, the same asphalt cement shall be used for the seal cost. If refined tar is used in the bituminous concrete wearing course, an asphalt cement shall be used in the seal coat and shall conform with either one of the specifications covering the physical and chemical proper- ties of asphalt cements included under the item entitled "Asphalt Cements for Seal Coat for Bituminous Concrete Pavement." Previous Service. The contractor will be required to show, to the satisfaction of the engineer, that the company manufacturing the asphalt cement or refined tar he proposes to use under a given speci- fication has, for a period of at least two years, manufactured asphalt cement or refined tar in a thoroly equipped plant, and that asphalt cement or refined tar manufactured of bituminous material obtained from a similar source to that which he proposes to use, shall have been in continuous and successful use for a period of at least two years in bituminous pavements constructed by the mixing method previous to the date of the letting in which his proposal was sub- mitted. Heating. The asphalt cement or refined tar shall be heated in kettles so designed as to admit of even heating of the entire mass, with an efficient and positive control of the heat at all times. Asphalt cement shall be heated as directed to a temperature between 135 C. (275 F.) and 177 C. (350 F.). All asphalt cement heated beyond 177 C. (350 F.), either before or during mixing with the broken stone, shall be rejected. Refined tar shall be heated 2 as directed to a temperature between 93 C. (200 F.) and 135 C. (275 F.). All tar heated beyond 135 C. (275 F.), either before or during mixing with broken stone, shall be rejected. No tar shall be heated in kettles containing any asphalt cement and in like manner no asphalt cement shall be heated in kettles containing any tar. Before changing from one type of material to the other, kettles shall be scrupulously cleaned in order to avoid mixtures of the two. Any such mixtures resulting from this cause shall be rejected. Thermometers Furnished by Contractor. The contractor shall provide a sufficient number of accurate, efficient, stationary ther- mometers for determining the temperatures of the asphalt cement or refined tar in kettles. Construction of Wearing Course Mixing. When thoroly heated to the temperature directed, the asphalt cement or refined tar and the broken stone for the bituminous concrete shall be mixed so that the resulting mixture shall contain between five (5) and eight (8) per cent by weight of bitumen, as directed, depending primarily upon the kind of bituminous cement and mineral aggregate which are used. A mixer shall be used, having revolving blades, and so designed and operated as to produce and discharge a thoroly coated and uniform mixture of non-segre- gated broken stone and bituminous cement. When discharged, mix- tures of asphalt cement and broken stone shall have a temperature not more than 149 C. (300 F.) and not less than 93 C. (200 F.) as directed. When discharged, mixtures of refined tar and broken stone shall have a temperature not more than 121 C. (250 F.) and not less than 66 C. (150 F.). Surface of Foundation. Before laying the bituminous concrete, the surface of the cement-concrete foundation shall be dry and thor- oly cleaned. If any defective areas exist in the cement-concrete foundation, they shall be repaired as directed at least ten (10) days in advance of laying the bituminous concrete. In cases where ce- ment-concrete edging is not used, compacted shoulders, forming a continuation of the surface of the foundation, shall be constructed. A two (2) inch plank shall be laid on each shoulder at the edge of the foundation. These planks shall remain in place until after the seal coat has been finished. Prevention of Dust. The shoulders of the road and adjacen f grounds shall be sufficient sprinkled during the placing of bitumin ous material wherever there would otherwise be danger of clouds ol dust blowing over the pavement. Laying Bituminous Concrete. The bituminous concrete, heated and prepared as specified, shall be delivered direct from the mixer to the point of deposition on the foundation in trucks or wagons, provided with canvas covers for retaining the heat. As delivered the bituminous concrete shall have a temperature of at least 66 C. (150 F.). Material having a lower temperature than this shall not be laid upon the foundation. The hot bituminous concrete shall be dumped upon platforms, constructed as directed, and shoveled with hot shovels into position on the foundation. The bituminous concrete shall be immediately uniformly spread over the foundation course by men experienced in such work and thoroly compacted by rolling. When compacted the wearing course shall have a thickness at no place of less than two (2) inches and shall be free from surface depressions and irregularities. The paving shall be done as continuously as practicable, to reduce to a minimum the number of joints between hot and cold materials. Such joints shall be constructed as directed. Rolling. The bituminous concrete wearing course, laid as speci- fied above, shall be rolled at once, while the mixture is warm and pliable, beginning at the edges and working toward the center. Means for preventing the bituminous material from adhering to the roller without injury to the bituminous concrete, shall be provided. Rolling shall continue without interruption until all roller marks disappear and the surface shows no further compressibility. Places which the roller cannot effectively reach shall be compacted with hot iron tampers. Roller. Rollers used on the bituminous concrete shall be w r ell balanced, self-propelled, tandem rollers, weighing between ten (10) and twelve (12) tons each. Each shall have a compression under the rear roller of between two hundred and fifty (250) and three hundred and fifty (350) pounds per linear inch of roll, and shall be provided with an ash pan, which shall prevent ashes from drop- ping onto the bituminous concrete or seal coat. Testing Surface. Before placing the seal coat, the surface of the bituminous concrete shall be tested wtih a four (4) foot straight edge laid longitudinally upon any portion of the surface, and any depression or other irregularity exceeding three-eighths (^) inch shall be satisfactorily eliminated. Seal Coat. As soon as possible after the compaction of the bituminous concrete, when the surface is clean and dry, a seal coat of the hot asphalt cement shall be evenly distributed over the bituminous concrete and uniformly spread by means of squeegees. The asphalt cement shall be applied at a temperature not less than 135 C. (275F.), nor more than 177 C. (350 F.), at a rate of one-half ( l / 2 ) to one (1) gallon per square yard, as directed. A thin, uniform layer of dry, clean broken stone chips shall be imme- diately uniformly spread in two applications over the asphalt cement by machines or skilled workmen. Each application of broken stone chips shall be rolled twice by a self-propelled, tandem roller. The spreading of the broken stone chips shall not lag more than twenty (20) feet behind the placing of the asphalt cement coating. Broken stone chips shall not be placed on the wearing course before the asphalt cement of the seal coat is applied. The surface of the bitu- minous concrete shall be kept scrupulously clean until the seal coat is applied, and the contractor shall not permit any hauling over the wearing course before the completion of the seal coat. Seasonal and Weather Limitations. No bituminous concrete shall be mixed or placed when the air temperature in the shade is below 10 C. (50 F.). Payment. Measurement and Payment. The quantity of bituminous con- crete wearing course to be paid for under this item shall be the num- ber of square yards, measured horizontally, satisfactorily completed in accordance with the specifications. The price stipulated in this item shall include the furnishing, crushing and screening of the broken stone, including the broken stone chips for the seal coat, and heating, mixing, placing and rolling of the broken stone and the asphalt cement or refined tar, and all work and expenses incidental to the completion of the bituminous concrete and the seal coat, except the furnishing of the bituminous cement, which will be in- cluded for payment under the item "Asphalt Cements and Refined Tars for Wearing Course of Bituminous Concrete Pavement" or the items " Asphalt Cements and Refined Tars for Wearing Course of Bituminous Concrete Pavement" and "Asphalt Cements for Seal Coat for Bituminous Concrete Pavement." Measurement under this item shall not include any pavement repaired or relaid, except as provided for in the following paragraph. Removing and Replacing Wearing Course. If the contractor removes, as directed, portions of the wearing course, and the work thus exposed for examination is found satisfactory, or if for any reason he shall be ordered to remove wearing course built in full accordance with his contract, he shall be paid for such excavation one-fourth the price per square yard stipulated in this item. If the wearing course after examination is found to be of acceptable quality, the original wearing course will be paid for as well as that used to refill the excavation. In connection with the removing and replacing of the wearing course in accordance w T ith this paragraph, no quantity shall be measured as less than one square yard. SPECIFICATIONS FOR ASPHALT CEMENTS AND REFINED TARS FOR WEARING COURSE OF BITUMINOUS CONCRETE PAVEMENT AND FOR ASPHALT CEMENTS FOR THE SEAL COAT IF AN ASPHALT CEMENT is USED IN THE BITUMINOUS WEARING COURSE. Asphalt Cement "A" Optional With Asphalt Cements "B," "C," "D," "E" and Refined Tars "F" and "G." ( 1 ) The asphalt cement shall be homogeneous, free from watei and shall not foam when heated to 177 C. (350 F.). (2) It shall show a flash point of not less than 205 C. (40O (3) Its specific gravity at a temperature of 25 C. (77 F.) shall be not less than 0.970 nor more than 1.000. (4) When tested with a standard No. 2 needle by means of a Dow penetrometer (or other penetrometer giving the same results as the Dow machine), it shall show penetrations within the follow- ing limits for the conditions stated, the penetrations being expressed in hundredths of a centimeter: 100 gram load, 5 seconds, at 25 C. (77 F.), from 75 to 90; 200 gram load, 1 minute, at 4 C. (39 F.), not less than 35; 50 gram load, 5 seconds, at 46 C. (115 F.), not more than 250. 6 (5) Its melting point as determined by the cube method shall be not less than 55 C. (131 F.). (6) When 50 grams of the material is maintained at a uniform temperature of 163 C. (325 F.) for 5 hours in an open cylin- drical tin dish, 5*/2 centimeters (about 2 1 /^ inches) in diameter, with vertical sides measuring approximately 3^ centimeters (about \ l / 2 inches) in depth, the loss in weight shall not exceed 1.0 per cent of the original weight of the sample. The penetration of the residue, when tested as described in clause (4) with a standard No. 2 needle under a load of 100 grams, for 5 seconds at 25 C. (77 F.) shall be not less than one-half the penetration of the original material tested under the same conditions. (7) Its bitumen as determined by its solubility in chemically pure carbon disulphide at room temperature shall not be less than 99.5 per cent. (8) It shall be soluble in chemically pure carbon tetrachloride at room temperature to the extent of not less than 99.5 per cent of its bitumen as determined by clause (7). (9) It shall be soluble in 86 to 88 Baume paraffin naphtha, at least 85 per cent distilling between 40 and 55 C. (104 and 131 F.) to the extent of not less than 70.0 per cent nor more than 80.0 per cent of its bitumen as determined by clause (7). (10) It shall yield not less than 8.0 per cent nor more than 12.0 per cent of fixed carbon. Asphalt Cement "B" Optional with Asphalt Cements "A," "C," U D," "E" and Refined Tars "F" and "G." ( 1 ) The asphalt cement shall be homogeneous, free from water and shall not foam when heated to 177 C. (350 F.). (2) It shall show a flash point of not less than 205 C. (400 F.). (3) Its specific gravity at a temperature of 25 C. (77 F.) shall be not less than 1.000 nor more than 1.030. (4) When tested with a standard No. 2 needle by means of a Dow penetrometer (or other penetrometer giving the same results as the Dow machine), it shall show penetrations within the follow- ing limits for the conditions stated, the penetrations being expressed in hundredths of a centimeter: 100 gram load, 5 seconds, at 25 C. (77 F.), from 90 to 100; 200 gram load, 1 minute at 4 C. (39 : F.), not less than 30. (5) Its melting point as determined by the cube method shall be not less than 50 C. (122 F.). (6) When 50 grams of the material is maintained at a uniform temperature of 163 C. (325 F.) for 5 hours in an open cylin- drical tin dish, ^ l / 2 centimeters (about 2 l /\. inches) in diameter, with vertical sides measuring approximately 3*/2 centimeters (about \ l / 2 inches) in depth, the loss in weight shall not exceed 1.0 per cent of the original weight of the sample. The penetration of the residue, when tested as described in clause (4) with a standard No. 2 needle under a load of 100 grams, for 5 seconds at 25 C. (77 F.) shall be not less than one-half the penetration of the original material tested under the same conditions. (7) Its bitumen as determined by its solubility in chemically pure carbon disulphide at room temperature shall not be less than 99.5 per cent. (8) It shall be soluble in chemically pure carbon tetrachloride at room temperature to the extent of not less than 99.5 per cent of its bitumen as determined by clause (7). . (9) It shall be soluble in 86 to 88 Baume paraffin naphtha, at least 85 per cent distilling between 40 and 55 C. (104 and 131 F.) to the extent of not less than 72.0 per cent nor more than 78.0 per cent of its bitumen as determined by clause (7). (10) It shall yield not less than 11.0 per cent nor more than 15.0 per cent of fixed carbon. Asphalt Cement "C" Optional With Asphalt Cements "A," "B," "D," "E" and Refined Tars "F" and "G." ( 1 ) The asphalt cement shall be homogeneous, free from water and shall not foam when heated to 177 C. (350 F.). (2) It shall show a flash point of not less than 205 C. (400 F.). 8 (3) Its specific gravity at a temperature of 25 C. (77 F.) shall be not less than 1.030 nor more than 1.040. (4) When tested with a standard No. 2 needle by means of a Dow penetrometer (or other penetrometer giving the same results as the Dow machine), it shall show penetrations within the follow- ing limits for the conditions stated, the penetrations being expressed in hundredths of a centimeter: 100 gram load, 5 seconds, at 25 C. (77 F.), from 70 to 90; 200 gram load, 1 minute, at 4 C. (39 F.), not less than 10. (5) Its melting point as determined by the cube method shall be not less than 45 C. (113 F.). (6) When 50 grams of the material is maintained at a uniform temperature of 163 C. (325 F.) for 5 hours in an open cylin- drical tin dish, 5 T /2 centimeters (about 2*4 inches) in diameter, with vertical sides measuring approximately 3^2 centimeters (about \ l /2 inches) in depth, the loss in weight shall not exceed 2.0 per cent of the original weight of the sample. The penetration of the residue, when tested as described in clause (4) with a standard No. 2 needle under a load of 100 grams, for 5 seconds at 25 C. (77 F.) shall be not less than one-half the penetration of the original material tested under the same conditions. (7) Its bitumen as determined by its solubility in chemically pure carbon disulphide at room temperature shall not be less than 99.5 per cent. (8) It shall be soluble in chemically pure carbon tetrachloride at room temperature to the extent of not less than 99.5 per cent of its bitumen as determined by clause (7). (9) It shall be soluble in 86 to 88 Baume paraffin naphtha, at least 85 per cent distilling between 40 and 55 C. (104 and 131 F.) to the extent of not less than 80.0 per cent nor more than 88.0 per cent of its bitumen as determined by clause (7). (10) It shall yield not less than 10.0 per cent nor more than 14.0 per cent of fixed carbon. Asphalt Cement "D" Optional With Asphalt Cements "A," "B," "C," "E" and Refined Tars "F" and "G." ( 1 ) The asphalt cement shall be homogeneous, free from water and shall not foam when heated to 177 C. (350 F.). 9 (2) It shall show a flash point of not less than 205 C. (400 F.). (3) Its specific gravity at a temperature of 25 C. (77 F.) shall be not less than 1.025 nor more than 1.050. (4) When tested with a standard No. 2 needle by means of a Dow penetrometer (or other penetrometer giving the same results as the Dow machine), it shall show penetrations within the follow- ing limits for the conditions stated, the penetrations being expressed in hundredths of a centimeter: 100 gram load, 5 seconds, at 25 C. (77 F.), from 85 to 95; 200 gram load, 1 minute, at 4 C. (39 F.), not less than 20. (5) Its melting point as determined by the cube method shall be not less than 50 C.( 122 F.). (6) When 50 grams of the material is maintained at a uniform temperature of 163 C. (325 F.) for 5 hours in an open cylin- drical tin dish, 5 T / 2 centimeters (about 2 1 /^ inches) in diameter, with vertical sides measuring approximately 3^ centimeters (about \y 2 inches) in depth, the loss in weight shall not exceed 2.0 per cent of the original weight of the sample. The penetration of the residue, when tested as described in clause (4) with a standard No. 2 needle under a load of 100 grams, for .5 seconds at 25 C. (77 F.) shall be not less than one-half the penetration of the original material tested under the same conditions. (7) Its bitumen as determined by its solubility in chemically pure carbon disulphide at room temperature shall not be less than 99.5 per cent. (8) It shall be soluble in chemically pure carbon tetrachloride at room temperature to the extent of not less than 99.5 per cent of its bitumen as determined by clause (7). (9) It shall be soluble in 86 to 88 Baume paraffin naphtha, at least 85 per cent distilling between 40 and 55 C. (104 and 131 F.), to the extent of not less than 67.0 per cent nor more than 77.0 per cent of its bitumen as determined by clause (7). (10) It shall yield not less than 12.0 per cent nor more than 18.0 per cent of fixed carbon. 10 Asphalt Cement "E" Optional With Asphalt Cements "A," "B," "C," "D" and Refined Tars "F" and "G." ( 1 ) The asphalt cement shall be homogeneous, free from water and shall not foam when heated to 177' C. (350 F.). (2) It shall show a flash point of not less than 165 C. (329 F-). (3) Its specific gravity at a temperature of 25 C. (77 F.) shall be not less than 1.040 nor more than 1.060. (4) When tested with a standard No. 2 needle by means of a Dow penetrometer (or other penetrometer giving the same results as the Dow machine), it shall show penetrations w 7 ithin the follow- ing limits for the conditions stated, the penetrations being expressed in hundredths of a centimeter: 100 gram load, 5 seconds, at 25 C. (77 F.), from 140 to 160; 200 gram load, 1 minute, at 4 C. (39 F.), not less than 40. (5) When tested by means of the New York Testing Labora- tory Float Apparatus, the float shall not sink in water maintained at 66 C. (150 F.) in less than 120 seconds nor more that 180 seconds. (6) When 50 grams of the material is maintained at a uniform temperature of 163 C. (325 F.) for 5 hours in an open cylin- drical tin dish, 5 l / 2 centimeters (about 2 1 /^ inches) in diameter, with vertical sides measuring approximately 3^ centimeters (about \ l / 2 inches) in depth, the loss in weight shall not exceed 3.0 per cent of the original weight of the sample. The penetration of the residue, when tested as described in clause (4) with a standard No. 2 needle under a load of 100 grams, for 5 seconds at 25 C. (77 F.) shall be not less than one-half the penetration of the original material tested under the same conditions. (7) Its bitumen as determined by its solubility in chemically pure carbon disulphide at room temperature shall be not less than 93.0 per cent nor more than 98.0 per cent. (8) It shall be soluble in chemically pure carbon tetrachloride at room temperature to the extent of not less than 98.5 per cent of its bitumen as determined by clause (7). 11 (9) It shall be soluble in 86 to 88 Baume paraffin naphtha, at least 85 per cent distilling between 40 and 55 C. (104 and 131 F.) to the extent of not less than 75.0 per cent nor more than 85.0 per cent of its bitumen as determined by clause (7). (10) It shall yield not less than 11.0 per cent nor more than 15.0 per cent of fixed carbon. (11) Upon ignition it shall yield not less than 1.0 per cent nor more than 3.0 per cent of ash. Refined Tar "F" Optional With Asphalt Cements "A," "B," "C," "D," "E" and Refined Tar "G." ( 1 ) The refined tar shall be homogeneous, free from water and shall not foam when heated to 150 C. (302 F.). (2) Its specific gravity at a temperature of 25 C. (77 F.) shall be not less than 1.160 nor more than 1.200. (3) When tested by means of the New York Testing Labora- tory Float Apparatus, the float shall not sink in water maintained at 50 C. (122 F.) in less than 140 seconds nor more than 170 seconds. (4) Its bitumen as determined by its solubility in chemically pure carbon disulphide at room temperature shall be not less than 95.0 per cent and it shall show not more than 0.2 per cent ash upon ignition of the material insoluble in carbon disulphide. (5) When distilled according to the tentative method recom- mended by Committee D-4 of the American Society for Testing Materials in 1911, it shall yield no distillate at a temperature lower than 170 C. (338 F.) ; not more than 7.0 per cent by weight shall distill below 270 C. (518 F.), and not more than 20.0 per cent by weight shall distill below 300 C. (572 F.). (6) The total distillate from the test made in accordance with clause (5) shall have a specific gravity at a temperature of 25 C. (77 F.) of not less than 1.000 nor more than 1.020. (7) The melting point, as determined in water by the cube method, of the pitch residue remaining after distillation to 300 C. (572 F.), in accordance with the test described in clause (5), shall be not more than 75 C. (167 F.). 12 Refined Tar "G" Optional With Asphalt Cements "A," "B," "C," "D," "E" and Refined Tar "F." ( 1 ) The refined tar shall be homogeneous, free from water and shall not foam when heated to 150 C. (302 F.). (2) Its specific gravity at a temperature of 25 C. (77 F.) shall be not less than 1.200 nor more than 1.300. (3) When tested by means of the New York Testing Labora- tory Float Apparatus, the float shall not sink in water maintained at 50 C. (122 F.) in less than 140 seconds nor more than 170 seconds. (4) Its bitumen as determined by its solubility in chemically pure carbon disulphide at room temperature shall be not less than 75.0 per cent nor more than 90.0 per cent, and it shall not show more than 0.2 per cent ash upon ignition of the material soluble in carbon disulphide. (5) When distilled according to the tentative method recom- mended by Committee D-4 of the American Society for Testing Materials in 1911, it shall yield no distillate at a temperature lower than 170 C. (338 F.) ; not more than 10.0 per cent by weight shall distill below 270 C. (518 F.), and not more than 20.0 per cent by weight shall distill below 300 C. (572 F.). (6) The total distillate from the test made in accordance with clause (5) shall have a specific gravity at a temperature of 25 C. (77 F.) of not less than 1.030. (7) The melting point, as determined in water by the cube method, of the pitch residue remaining after distillation to 300 C. (572 F.), in accordance with the test described in clause (5), shall be not more than 75 C. (167 F.). SPECIFICATIONS FOR ASPHALT CEMENTS FOR SEAL COAT FOR BITUMINOUS CONCRETE PAVEMENT WHEN REFINED TAR is USED IN THE BITUMINOUS CONCRETE WEARING COURSE. Asphalt Cement "H" Optional With Asphalt Cements "K" and "L." (1) The asphalt cement shall be homogeneous, free from water and shall not foam' when heated to 177 C. (350 F.). 13 (2) It shall show a flash point of not less than 205 C. (400 F.)- (3) Its specific gravity at a temperature of 25 C. (77 F.) shall be not less than 0.970 nor more than 1.000. (4) When tested with a standard No. 2 needle by means of a Dow penetrometer (or other penetrometer giving the same results as the Dow machine), it shall show penetrations within the follow- ing limits for the conditions stated, the penetrations being expressed in hundredths of a centimeter: 100 gram load, 5 seconds, at 25 C. (77 F.), from 60 to 75; 200 gram load, 1 minute, at 4 C. (39 F.), not less than 50; 50 gram load, 5 seconds, at 46 C. (115 F.), not more than 150. (5) Its melting point as determined by the cube method shall be not less than 80 C. (176 F.). .(6) When 50 grams of the material is maintained at a uniform temperature of 163 C. (325 F.) for 5 hours in an open cylin- drical tin dish, 5j/2 centimeters (about 2^4 inches) in diameter, with vertical sides measuring approximately 3j/2 centimeters (about l l /2 inches) in depth, the loss in weight shall not exceed 1.0 per cent of the original weight of the sample. The penetration of the residue, when tested as described in clause (4) with a standard No. 2 needle under a load of 100 grams, for 5 seconds at 25 C. (77 F.) shall be not less than one-half the penetration of the original material tested under the same conditions. . (7) Its bitumen as determined by its solubility in chemically pure :arbon disulphide at room temperature shall not be less than 99.5 per cent. (8) It shall be soluble in chemically pure carbon tetrachloride at room temperature to the extent of not less than 99.5 per cent of its bitumen as determined by clause (7). (9) It shall be soluble in 86 to 88 Baume paraffin naphtha, at least 85 per cent distilling between 40 and 55 C. (104 and 131 F.) to the extent of not less than 70.0 per cent nor more than 80.0 per cent of its bitumen as determined by clause (7). (10) It shall yield not less than 8.0 per cent nor more than 12.0 per cent of fixed carbon. 14 Asphalt Cement "K" Optional With Asphalt Cements "H" and "L." ( 1 ) The asphalt cement shall be homogeneous, free from water and shall not foam when heated to 177 C. (350 F.). (2) It shall show a flash point of not less than 205 C. (400 F.). (3) Its specific gravity at a temperature of 25 C. (77 F.) shall be not less than 1.030 nor more than 1.045. (4) When tested with a standard No. 2 needle by means of a Dow penetrometer (or other penetrometer giving the same results as the Dow machine), it shall show penetrations within the follow- ing limits for the conditions stated, the penetrations being expressed in hundredths of a centimeter: 100 gram load, 5 seconds, at 25 C. (77 F.), from 60 to 70; 200 gram load, 1 minute, at 4 C. (39 F.), not less than 18; 50 gram load, 5 seconds, at 46 C. (115 F.), not more than 270. (5) Its melting point as determined by the cube method shall be not less than 60 C. (140 F.). (6) When 50 grams of the material is maintained at a uniform temperature of 163 C. (325 F.) for 5 hours in an open cylin- drical tin dish, 5^ centimeters (about 2}/\ inches) in diameter, with vertical sides measuring approximately 3^ centimeters (about \ l /> inches) in depth, the loss in w r eight shall not exceed 1.0 per cent of the original w r eight of the sample. The penetration of the residue, when tested as described in clause (4) with a standard No. 2 needle under a load of 100 grams, for 5 seconds at 25 C. (77 F.) shall be not less than one-half the penetration of the original material tested under the same conditions. (7) Its bitumen as determined by its solubility in chemically pure carbon disulphide at room temperature shall not be less than 99.5 per cent. (8) It shall be soluble in chemically pure carbon tetrachloride at room temperature to the extent of not less th?n 99.5 per cent of its bitumen as determined by clause (7). (9) It shall be soluble in 86 to 88 Baume paraffin naphtha, at least 85 per cent distilling between 40 and 55 C. (104 and 15 131 F.) to the extent of not less than 70.0 per cent nor more than 80.0 per cent of the bitumen as determined by clause (7). (10) It shall yield not less than 12.0 per cent nor more than 16.0 per cent of fixed carbon. Asphalt Cement "L" Optional with Asphalt Cements "H" and "K." ( 1 ) The asphalt cement shall be homogeneous, free from water and shall not foam when heated to 177 C. (350 F.). (2) It shall show a flash point of not less than 205 C. (400 F.). (3) Its specific gravity at a temperature of 25 C. (77 F.) shall be not less than 1.025 nor more than 1.055. (4) When tested with a standard No. 2 needle by means of a Dow penetrometer (or other penetrometer giving the same results as the Dow machine), it shall show penetrations within the follow- ing limits for the conditions stated, the penetrations being expressed in hundredths of a centimeter: 100 gram load, 5 seconds, at 25 C. (77 F.), from 60 to 70; 200 gram load, 1 minute, at 4 C. (39 F.), not less than 16. (5) Its melting point as determined by the cube method shall be not less than 55 C. (131 F.). (6) When 50 grams of the material is maintained at a uniform temperature of 163 C. (325 F.) for 5 hours in an open cylin- drical tin dish, 5y^ centimeters (about 2}/\ inches) in diameter, with vertical sides measuring approximately 3^ centimeters (about \]/2 inches) in depth, the loss in weight shall not exceed 1.0 per cent of the original weight of the sample. The penetration of the residue, when tested as described in clause (4) with a standard No. 2 needle under a load of 100 grams, for 5 seconds at 25 C. (77 F.) shall be not less than one-half the penetration of the original material tested under the same conditions. (7) Its bitumen as determined by its solubility in chemically pure carbon disulphide at room temperature shall not be less than 99.5 per cent. 16 (8) It shall be soluble in chemically pure carbon tetrachloride at room temperature to the extent of not less than 99.5 per cent of its bitumen as determined by clause (7). (9) It shall be soluble in 86 to 88 Baume paraffin naphtha, at least 85 per cent distilling between 40 and 55 C. (104 and 131 F.), to the extent of not less than 67.0 per cent nor more than 77.0 per cent of its bitumen as determined by clause (7). (10) It shall yield not less than 13.0 per cent nor more than 18.0 per cent of fixed carbon. Delivery. The asphalt cement or refined tar shall be delivered in suitable containers, far enough in advance of its use in the work to permit the necessary tests to be made. Each container shall be plainly labeled with the trade name of the asphalt cement or refined tar, name of manufacturer, gross weight and net weight. Each shipment and each carload shall be kept separate. Bills of Lading. The contractor shall furnish the engineer on or before the arrival of each shipment at or near the site of the work, bills of lading, or correct copies thereof, which shall state the trade name of the asphalt cement or refined tar, and the name and address of the company manufacturing and supplying it. Samples. Samples will be taken by the engineer from each carload of asphalt cement or refined tar when delivered at the work, unless satisfactory arrangements can be made for sampling before shipment. Such samples shall be analyzed by the engineer to assure the delivery of an asphalt cement or refined tar of the specified quality and to determine, for purpose of payment, the quantity of bitumen. Work Included. Under this item the contractor shall furnish and deliver on the work at such points as directed an asphalt cement or an asphalt cement and a refined tar, which conform with the specifications heretofore mentioned. All asphalt cement or refined tar for any pavement of a given contract shall be furnished by one manufacturer and no change in type or grade of bituminous cement used in the bituminous concrete or the seal coat shall be allowed in any pavement of a given contract without written permission from the engineer. Measurement and Payment. The quantity of bitumen in the asphalt cement or refined tar, to be paid for under this item, 17 shall be the number of tons, determined in accordance with the para- graph headed "Samples," contained in the asphalt cement or refined tar placed in the pavement in accordance with the specifications and requirements, or used as directed for other purposes. The percentage of bitumen determined by an average of the analyses of the acceptable samples taken by the engineer during a given month, shall be used as the basis for payment for the asphalt cement or refined tar used during that month. Asphalt cement or refined tar that is wasted shall not be included in the measurement under this item. The price stipulated in this item shall include the cost of furnishing, hauling and delivering the asphalt cement or refined tar at points on the work where it is to be used, and all expenses incidental thereto. UNIVERSITY OF CALIFORNIA LIBRARY