THE INFLUENCE OF FINES CONTENT AND PLASTICITY ON THE STRENGTH AND PERMEABILITY OF AGGREGATE FOR BASE COURSE MATERIAL

The quantity and type of fines have a major influence on the performance of an unbound aggregate road-base. The Indonesian specification for aggregate base Class-A permits a fines content in the range of 0% to 8%; the quantity of fines is controlled by limiting the maximum values of Plasticity Index (PI) and Liquid Limit (LL) to 6% and 25%, respectively. This paper describes an investigation into the influence of fines content and type on the strength and permeability of aggregate base Class-A. Fines content investigated were 0, 4, 8, 12 and 16%; the fines had PI values of 0%, 9.47% and 24.09%. Results result indicates that PI is the most effective parameter for controlling the strength of the mix as it appears to be independent of fines type. Significant reduction in permeability occurs when 4% fines is added.