Influence of Fines on Strength and Drainage Characteristics of Aggregate Bases

摘要

Type 21B is one of the most commonly used dense-graded aggregate mixes inVirginia. To improve the drainage characteristics of the 21B material, a decrease in the maximum allowable percentage of fines from 7% to 5% was proposed, while retaining the existing percentage ranges for coarse particles. Before implementing this modification, the Virginia Department of Transportation (VDOT) conducted a series of laboratory tests to assess the potential impact of the revised material specifications. Samples of 21B aggregates produced by 19 quarries in Virginia and in North Carolina were analyzed. The results showed no statistically significant relationship between the percentage of fines and the coefficient of permeability.