Optimization of Ternary Activator for Enhancing Mechanical Properties of Carbonized Cementitious Material Based on Circulating Fluidized Bed Fly Ash

Abstract

In this study, circulating fluidized bed fly ash (CFBFA) non-sintered ceramsite was innovatively developed. The CFBFA was addressed by adding ternary activator (including cement, hydrated lime, and gypsum) to prepare ceramsite. In the curing process, the use of power plant flue gas for curing not only captured greenhouse gas CO2, but also enhanced the compressive strength of the ceramsite. The compressive strength of the composite gravels prepared by the CFBFA was modeled using a novel approach that employed the response surface methodology (RSM) and artificial neural network (ANN) coupled with genetic algorithm (GA). Box–Behnken design (BBD)-RSM method was used for the independent variables of cement content, hydrated lime content, and gypsum content. The resulting quadratic polynomial model had an R2 value of 0.9820 and RMSE of 0.21. The BP-ANN with a structure of 3-10-1 performed the best and showed better prediction of the response than the BBD-RSM model, with an R2 value of 0.9932 and RMSE of 0.19. The process parameters were optimized using RSM optimization tools and GA. Validation experiments showed that the GA-ANN prediction results were more accurate than the BBD-RSM results.