Workability and mechanical properties for GGBFS–MK geopolymer synthesis: influencing factor analysis and a mix design method.

In this study, the fluidity, setting time, and compressive strength for 40%/60% ground granulated blast furnace slag (GGBFS)/metakaolin (MK) based geopolymer synthesis were experimentally investigated. By conducting 120 groups of tests, the effects of three design parameters of the alkaline activator, including the alkaline activator concentration, modulus, and liquid–solid ratio, were systematically analyzed. The test results show that the compressive strength of the GGBFS–MK geopolymer synthesis reaches a maximum value for a modulus of 1.2 or 1.4. Furthermore, according to the experimental results obtained, a series of contour plots for the relationship between the influencing parameters and the workability and mechanical properties for GGBFS–MK geopolymer synthesis are summarized. Then, a mix design method is proposed. Appropriate combinations of the concentration and modulus that can be used to generate a target compressive strength and fluidity are identified from the contour plots for different liquid–solid ratios. This method can be used to determine the mix proportion design for GGBFS–MK geopolymer synthesis that shows a specified compressive strength and working performance. [ABSTRACT FROM AUTHOR]