AASHTO T180-95 pdf free download

AASHTO T180-95 pdf free download.Moisture-Density Relations of Soils Using a 4.54-kg [10-lb] Rammer and a 457-mm [18-in.] Drop.
NOTE 3- -The mechanical rammer appa- ratus shall be calibrated with several soil types and the mass of the rammer adjusted, if neces- sary, to give the same moisture-density results as with the manually operated rammer. It. may be impractical to adjust the mechanical apparatus so the free fall is 457- mm (18 in.) each time the rammer is dropped, as with the manually operated rammer. To make the adjustment of free fall, the portion of loose soil to receive the initial blow should be slightly compressed with the rammer to establish the point of impact from which the 457 mm (18 in.) drop is determined, subse- quent blows on the layer of soil being com- pacted may all be applied by dropping the rammer from a height of 457 mm (18 in.) above the initial-setting elevation; or when, the mechanical apparatus is designed with a height adjustment for each blow, all subse- quent blows should have a rammer free fall of 457 mm (18 in.) measured from the eleva- tion of the soil as compacted by the previous blow. A more detailed calibration procedure for laboratory mechanical rammer soil com- pactors can be found in ASTM D 2168. .
NOTE 4 – -The capacity of the metric bal- ance or scale should be approximately 11.5 kg when used to determine the mass of the 152-mm (6-in.) mold and compacted, moist soil; however, when the 102-mm (4 in.) mold is used, a balance or scale of lesser capacity than 115 kg may be used, if the sensitivity and readability is 5 g. 2.5 Drying Oven- -A thermostati- cally cotroled drying oven capable of maintaining a temperature of 110土5°C (230土9°F) for drying moisture samples. 2.6 Straightedge- A hardened steel straightedge at least 250 mm (10 in.) in length. It shall have one beveled edge, and at least one longitudinal surface (used for final trimming) shall be plane within 0.1 percent of the length within the portion used for trimming the soil (Note 5). NOTE 5- -The beveled edge may be used for final trimming if the edge is true within a tolerance of 0.25 mm per 250 mm (0.1 percent) of length; however, with continued use, the cutting edge may become excessively wom and not suitable for trimming the soil to the level of the mold. The straightedge should not be so fexible that trimming the soil surface with the cutting edge will cause a concave soil surface.
4. PROCEDURE 4.1 Thoroughly mix the selected rep- resentative sample with sufficient water to dampen it to approximately four per- centage points below optimum mois- ture conteat. 4.2 Form a specimen by compacting the prepared soil in the 101.60-mm (4 in.) mold (with collar attached) in five approximately equal layers to give a total compacted depth of about 125 mm (5 in.). Compact each layer by 25 uniformly distributed blows from the rammer drop- ping free from a height of 457.2 mm (18 in.) above the elevation of the soil when a sleeve-type rammer is used, or from 457 mm (18 in.) above the approxi- mate elevation of the soil as compacted by the previous blow wben a stationary mounted type of rammer is used (Note 6). NOTE 6- -Each of the following has been found to be a satisfactory base on which to rest the mold during compaction of the soil: A block of concrete, with a mass of not less than 90 kg (200 lb), supported by a relatively stable foundation; a sound concrete floor, and for field application, such surfaces as found in concrete box culverts, bridges. and pavements.AASHTO T180-95  pdf download.