Strength and Permeability of No-Fines Concrete Made with Supplementary Cementitious Materials

Abstract

No-fines concrete (NFC) has a large volume of voids and a porous nature which reduces the rainwater runoff, recharges the groundwater table, and reduces noise from vehicle tire movement. The elimination of sand and the high amount of voids in NFC leads to a decrease in the strength. Therefore it can be used only in limited practical applications. An attempt was made in this study to improve its strength without compromising its porosity and permeability properties by utilizing optimum levels of supplementary cementitious materials (SCM)—rice husk ash (RHA) and silica fume (SF)—as partial replacement of cement. Results indicated significant improvement in compressive strength by 16.40% with 10% replacement of cement by SF at 90 days, and 25.04% increase with 5% RHA at 90 days. The results were well supported by microstructural analysis of NFC mixes with SCM replacement, which showed a dense and compact micrograph. Permeability and porosity decreased very marginally with SF and RHA replacement at optimum levels without much affecting the drainage properties. The improved compressive and flexural strength and abrasion resistance of NFC with RHA and SF as SCMs indicated applicability in medium-traffic applications.