Improvisation of dense matrix of reactive powder concrete by zircon sand and sillimanite

Abstract

This paper presents a comparative study of compressive strength and ultrasonic-pulse velocity of Reactive Powder concrete (RPC) blended with micro and Nano filler materials. The material composition of RPC includes partial replacement of High Alumina Cement by alccofine and Quartz sand by zircon sand and sillimanite in order to obtain a dense concrete matrix of low level porosity. Micro-steel fibers were used to enhance the ductility of concrete composite. Polycarboxylate based super plasticizer was used to improve the workability. The experimental program comprises of compressive strength test and ultrasonic-pulse velocity test of standard water cured samples and heat treated samples at elevated temperatures of 200°C, 400°C, 600°C and 800°C. The influence of micro-filler materials in hydrated samples and microstructure of RPC specimens were examined by Scanning Electron Microscope (SEM) analysis. The results showed that the combined role of zircon sand and sillimanite as a filler material and high alumina cement as a refractory material made the RPC to exhibit ultra-high performance with increase in temperature and tends to decrease after 600°C.