Studies of rice husk ash nanoparticles on the mechanical and microstructural properties of the concrete

The usage of waste materials which are having cementitious properties such as fly ash, silica fume, slag cement, rice hush ash and cow dung ash etc., has been increased in the construction industries due to its pozzolanic activities. These materials are used as a partial replacement with cement which would reduce the carbon dioxide emission from the cement industry and environmental pollution. In this study, agricultural waste such as Rice Husk Ash (RHA) was used as a partial replacement of Ordinary Portland Cement (OPC) which was obtained by combustion of rice husk at controlled temperature. The size of the RHA was analyzed and observed as nanoparticles which were confirmed as similar to 50-70 nm. Two different types of M30 grade concrete such as, concrete with partially replaced by Fly ash (FA) and concrete with partially replaced by RHA were prepared. The 20% and 3% replacement of cement by flyash and RHA was maintained respectively. The compressive, split tensile and flexural strength was measured to know the mechanical properties of the two types of concrete after the curing period of 7 days, 28 days and 56 days. The microstructural properties such as X-ray diffraction (XRD) and field scanning electron microscopy (FESEM) showed the presence of amorphous silica and scanning electron microscope showed the fineness of the RHA which increases the strength of the concrete. (C) 2015 Elsevier Ltd. All rights reserved.