Properties of metakaolin based geopolymer incorporating calcium carbonate

An alkaline solution, thermally activated kaolinite clay and a mineral additive (calcium carbonate) were mixed with the aim to elaborate a geopolymer material with physical and mechanical properties comparable to those of classical construction materials. The starting reagents were characterized by quantitative chemical analyses (XRF), mineralogical analyses (XRD), thermal gravimetric analyses (TGA), and grain size distribution measurements. The setting of the mixture (polymerization) was implemented by measuring the evolution of the viscosity as a function of time at different temperatures. The geopolymers were synthesized at a temperature of 40 degrees C. The investigation of the mechanical behavior reveals that these materials display acceptable characteristics: the flexural and compression strength are around 4.6 and 26 MPa respectively, for an added calcium carbonate over dry matter ration up to 12% by weight. The promising results exposed in this paper show that the geopolymer formulations can be adapted for applications in construction and civil engineering structures as an alternative to conventional materials. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.