AN EXPERIMENTAL STUDY ON MECHANICAL PROPERTIES OF HIGH PERFORMANCE CONCRETE USING NANO SILICA, SILICA FUMES AND GGBFS

Abstract

The present study aims at developing the concrete mixture incorporating nano silica, silica fumes, and ground granulated blast furnace slag as partial replacement of cement. The aim is to study the mechanical properties of high performance concrete mixes using the local materials and to compare it with the control concrete mixes i.e. without any mineral admixture. Cement was replaced by nano silica with 2% and 3%, silica fumes with 5%, 7.5% and 10% and ground granulated blast furnace slag with 20% in the mixes respectively. The design mix was worked out as per ACI guidelines and various trials were performed to obtain the mix of desired grade (M70) at 28 days. In this study, the compressive strength, split tensile strength and flexural strength of HPC concrete mixtures for different percentage of replacement of cement with mineral admixtures are obtained at 7 and 28 days respectively. After analysis of test results it was seen that the performance of HPC mixes in terms of mechanical properties was better than their corresponding control mixes. Cube compressive strength of mixes showed 3% - 16% of increase in strength when compared with control mixes. Split tensile strength of mixes was found to be 6% - 8% of its cube compressive strength. Flexural strength of mixes was found to be 9% - 11.5% of its cube compressive strength. It is found that the maximum increase in compressive strength, split tensile strength and flexural strength is for concrete mix in which 2% nano silica, 7.5% silica fume and 20% ground granulated blast furnace slag is replaced with cement.