Refractory and Mechanical Properties of Dealuminated Kaoline-Based Geopolymer Concrete

Abstract

This study has been performed to evaluate the performance of the industrial by-product dealuminated kaolin (DK) as geopolymer paste in production a refractory concrete. The paper study the thermal and mechanical properties of concrete mixtures containing crushed refractory brick as combined aggregate and geopolymer paste produced from the blend of 10%, 20% and 30% of DK, ordinary Portland cement (OPC), solution of sodium hydroxide and sodium silicate as alkaline activator. These concrete mixtures were tested for workability, shrinkage at 400,800 and 1200 °C, thermal shock resistance at temperature of 950 °C, Cold crushing strength, tensile strength, and elastic modulus. The results of these mixtures compared with the results of concrete mixtures containing 100% OPC and 100% aluminous cement (AC) .The results show that the thermal and mechanical properties of geopolymer concrete produced by dealuminated kaolin (DK) are enhanced. Also, it is found that mixture contains 20% of DK appears to be the optimal geopolymer concrete mixture.