Study Of Basic Mechanical Properties And Influential Factors Of Metakaolin-based Geopolymer

Geopolymer is a new kind of cementitious material. It classifies a kind of inorganic materials which have the polymer-like three dimensional microstructures and amorphous or semi-crystalline aluminosilicate composition. It is also a kind of alkali activated cementing material. This material is usually processed from the alkali activating of natural minerals or industrial wastes with low calcium content. Geopolymer has high early strength and good resistance of corrosion, freezing-thawing and high temperature. It also has a much lower CO2emission and energy consumption comparing with Portland cement in production. So geopolymer is an earth-friendly material with high performance.This paper is focus on the typical metakaolin-based geopolymer. The basic properties and mechanical performance was studied in this paper. The main work and achievements of this paper are listed below.Firstly, the setting time, bulk density and residual alkalinity of metakaolin-based geopolymer paste was studied. As a result, the correlations between these properties and the composition of geopolymer paste were clarified. At the same time, the practical relation images were achieved.Secondly, a detailed measurement of basic mechanical performances including the uniaxial compressive strength, Young’s modulus. Poisson’s ratio and etc. were conducted. Through the study of the influence of the composition, mathematical relations between mechanical parameters and compositional parameters were established.Thirdly, the compressive strength, flexural strength and splitting strength of metakaol in-based geopolymer mortar were tested. The relations between compositional parameters and strengthes were further studied. A mathematical function describing the strength development of geopolymer mortar was established. And at the same time, the influence of the hardening condition was also studied.Finally, the geopolymer-waste concrete composite was studied. The compressive strength of the GWC material could reach30MPa though the waste concrete content was above50%.