Soil is compact to prepare it to plump for roads and building foundations . This increase its density and strength . The American Society for Testing and Materials ( ASTM ) , has issue standards for how to test ground compaction and soil conditions after compaction . These test determine how much compaction is required to better the soil ’s shear strength and permeability .
Step 1
The original Proctor examination uses the " firm stroke " of a hammer called a rammer . agree to " Geotechnical Testing , Observation , and Documentation " by Tim Davis , " the standard Proctor utilizes a 5.5 lb . hammer with a 12 in pearl and three layers " of soil in a cylindrical mold . The received Proctor trial creates a force-out of 12,400 foot pound per three-dimensional metrical unit when it fall .
Modified Proctor Test
The modified Proctor run uses a heavier hammer , greater drop height , and more soil layers than the original Proctor test . According to " Slope Stability and Stabilization Methods " by Lee Abramson , " ASTM D1557 - 78 urge a 44.6 newton ( 10 pound ) rammer with a 457 millimetre ( 18 inch ) drop for compacting five layers of soil in a 102 or 154 mm molding . " The modified form of the Proctor test use a free - drib of the malleus so as to palliate the variable effects of the " firm stroke " in the original trial run . The hammer is dropped 25 time . The limited Proctor test make a forcefulness of about 56,000 feet - Lebanese pound per cubic foot . According to " Geotechnical Investigation Methods " by Roy Hunt , " materials containing significant amounts of crushed rock are compact in a 6 inch diameter modeling by 56 blow on each of the five layer . " ASTM D4718 defines how to decline the whole weightiness of soil that contains over - sized particles like gravel .
Step 2
Dry Weight Determination
After the Proctor mental testing or modify Proctor test is completed , the dirt book and water content are determine . The dry free weight of the grime is determined from those value . According to ASTM D1557 , " the point of soil crunch required to attain the desire technology properties is often specified as a pct of the change maximal ironic unit system of weights . " Modified maximum ironical unit weight can be determined by function in ASTM D698 . ASTM D4914 can watch the un - compacted dry unit free weight . ASTM D4914 is the trial run method acting of regain unit weight of filth using the sand switch method . ASTM D6913 defines how to determine the particle sizing distribution via a sieve to determine if correction via ASTM D4718 is necessary .
Related Standards
ASTM D2168 is the process for calibrating the mechanically skillful rammer grime compactor . ASTM D2216 is the procedure for determine the moisture content of the filth . ASTM D854 is the method for finding the specific gravity of soil via piss pyconmeter . ASTM D4253 is the process of finding unit weight of dirt by using a vibrator board .
References
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