An Experimental Study on the Performance of Bituminous Concrete Mixtures with Silica Sand as Filler Replacement

Abstract

This study investigates the performance of silica sand as a partial replacement for cement filler in bituminous concrete mixtures. The physical properties of bituminous concrete mixture constituent materials were tested in accordance with American Society for Testing and Materials ASTM and British standard BS specifications and were found to be satisfactory. Marshall stability method of bituminous concrete mix design was adopted to determine the optimum binder content  at no silica sand replacement (control) within the bitumen content range prescribed by Nigerian General Specifications for Roads and Bridges and Asphalt Institute for bituminous courses in flexible pavements and an optimum binder content (OBC) of 6% was obtained. The Marshall stability-flow and void-density analysis of bituminous concrete mixtures prepared with 6% OBC at varying percentages replacement (5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, and 45%) of silica sand was conducted to obtain the mixture with the best performance in terms of strength and waste utilization. The results obtained from the experiment shows that the replacement of cement filler with silica sand up to 45% meets the standard specifications of Nigerian General Specifications for Road and Bridges, Hence, silica sand up to 45%  could be partially adapted as cement filler replacement in  bituminous concrete mixes.