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Soil T-224



January 2012



Correction for Coarse Particle in the Soil Compaction Test AASHTO T-224 (1996) (Modified) This method describes a procedure whereby the maximum soil density determined by AASHTO T-99, Method C, may be adjusted to compensate for differing percentages of coarse particles retained on the 4.75 mm (No. 4) sieve when performing the density of soil and soil-aggregate inplace. This correction for coarse particles involves no testing but instead utilizes the results of other tests, and mathematically combines the results. Modification: 1. Only AASHTO T-99, Method C, shall be utilized. 2. The TTCP will continue to utilize the AASHTO T-224 (1996) version with nomographs, not the 2004 version that utilizes Adjustment Equations. Key Elements: 1. Use the correction nomograph, Figure 2 for Method C (2.2.1), to determine the adjusted maximum dry density from the percentage of coarse particles retained on the 4.75 mm (No. 4) sieve. 2. Determine bulk specific gravity of coarse aggregate. Determine the bulk specific gravity of the coarse aggregate according to AASHTO T-85. This test shall be run on the same material used in the AASHTO T-99 moisture-density relation test. 3. Determine percentage of in-place coarse aggregate. Determine the percentage of coarse particles retained on the 4.75 mm (No. 4) sieve from a representative sample when performing the density of soil and soil-aggregate in-place (2.2.1.1). 4. Determine adjusted maximum dry density. Using nomograph Figure 2, follow instructions and plot data to determine adjusted maximum dry density (4.1, 4.2). 5. Record and report. Record the adjusted maximum dry density, original maximum dry density, bulk specific gravity (air dry) of coarse aggregate, and percentage of coarse particles retained on the 4.75 mm (No. 4) sieve for the in-place material. Report the percent compaction of in-place soil and soil aggregate. Report the percentage of coarse material retained above the 4.75 mm (No. 4) for each individual test.



New Mexico Technician Training and Certification Program



Soil T-224



New Mexico Technician Training and Certification Program



January 2012