Downloaded from https://www.everyspec.com MIL-SW20A 13 Jonwv 1965 Method 100 UNIT WEIGHT. MARSHA1,I, STAWI JTY, AN1) V[,OW OF” Bituminous itllX’1’tIIIF.S 1. SCOPE by l-inch stwl plutc, auplwrted by G Ii!- bY 12- by 2-inch word scrtion over thti 6- by 6-inch post if arraniremcnts tire made for placing the compaction mold directiy over the 6- by 6-inch post. The compaction pedestal must be placed on a concrete floor slab or base resting on the ground, or directly over an interior building column or similar location. Wooden floors or unsup- ported areas of concrete floors are unsuit- able supports for the compaction pedestal.
The provision of a pedestrd in accordance with these requirements is very important; otherwise the compaction obtained will not agree with field conditions. 1.1 This test methud is applicable fot’ evacuation uf uI1 hoLmix bituminous pave- ment mixes in which not more than 10 percent of the aggregate is greater than 1 inch in size. 2 APPARATUS 2.1 Specimen mold assembly. Mold cylin- ders 4 inches in diameter by 3 inches height, base plates, and extension collars, as shown in figure 100-1, and conforming to details shown in figure 100-2. Six mold cylinders, two base plates, and two exten- sion collars are recommended. Z5 Specimen mold holder.
A steel or cwjt-iron holder (figure 100-2) consisting of a semicircular base and a circular top to hold the specimen mokl in place during compaction of the specimen. The top section should be fianged to fit over the collar of the specimen mold und should be attached to the base by means of a fulcrum on one side and n tension spring on the other. Two holes shall be provided in the base for mounting the holder on the compaction]] pedestal. The specimen mold holder shall be mounted OMthe pedestal cap so that the center of the mold is over the center of the post, 22 Specimen extractor. A specimen ex- tractor or plunger (figure 100-2) for push- ing the compacted specimen from the mold -.
cylinder by tlie use of a jack and frame. 2.3 Comwction hammer. A compaction hammer (figures 100-1 and 100-3) having n flat, circular tamping face and a 10-lb. sliding weight with a frcw fall of 18 inches. Two compaction hammers are recommended. NOTE: Mechanical hammers may he used when properly correlated with the standard hand hammer by determining number of blows to use to produce same density as that produced by hand hammer. 2.6 Breaking head. A breaking head (figures 100-1 and 100-4 ) consisting of ~lpper and lower cylindrical segments or test heads which have an accurately ma- chined inside radius of curvature of 2 inches.
The lower segment shall be mounted on n bme having two perpendicular guide rods or posts extending upward. Guide sleeves in the upper se~ent shall be posi- 2.4 Compaction pedestal. A pedestal, on which to rest the mold during compaction of the test specimen, consisting of a timber post having a minimum cross section of 51Z: by 51~ inch (nominal 6 by 6 inches), capped by a l-inch-thick steel plate. The pedestal cap may consist of a 12- by 12. Method 100 3 . .