Effect of Silica Fume and Nano Silica as Cement Replacement Material on Strength Properties of Pavement Quality Concrete (PQC)

Abstract

Civilization also produces waste products. Disposal issue of the waste products is a challenge. Some of these materials are not biodegradable and often leads to waste disposal crisis and environmental pollution. Government policies and public awareness is also contributing to the enhancement of utilization in road pavements. Silica fume and nano silica have been widely used in road pavements. On other hand, silica fume has no use since it is a produced only as a byproduct which causes health hazards. Therefore, it could be possible to consume fewer natural resources as well through its utilization in increasing demand for road construction. The present study aim at, developing pavement quality concrete mixtures incorporating silica fume and nano silica as partial replacement of cement. The purpose is to design the slab thickness of Pavement Quality Concrete (PQC) pavement using the achieved flexure strength of the concrete for different w/c ratios with replacement of cement by 5% silica fume and nano silica. It is found that the maximum increase in flexure strength and compressive strength is for 5% silica fume and 2% nano silica at w/c of 0.40. Due to this increase in the flexural strength it is possible to achieve a saving in cost of PQC construction. In this study it has been observed that the replacement of cement with 5% silica fume and 2% nano silica in PQC, the maximum increase in the flexural strength is observed for mixes containing silica fume and nano silica. This satisfy the IRC specifications of PQC and also saves the cement used in concrete leading to economical design of the concrete slab for the pavement.