Strength-based design mix methodology of one-part geopolymer concrete using response surface methodology

The study proposed a strength-based design mix methodology for normal- and medium-strength one-part Geopolymer Concrete (GPC) using Response Surface Methodology (RSM). The various factors affecting the compressive strength of one-part GPC were considered in the form of input parameters which include the content of Ground Granulated Blast Furnace Slag (GGBS), fly ash, anhydrous sodium metasilicate, water, coarse aggregates and fine aggregates. The statistical performance of the model generated in RSM demonstrated a notable correlation between input and output parameters obtained from ANOVA analysis and the model statistical evaluation. The design mixes obtained from the RSM were further validated experimentally in the laboratory. The targeted compressive strength for the normal- and the medium-strength one-part GPC were 30 MPa and 50 MPa, respectively, in the model. The measured values of compressive strength in the laboratory were in the range of 31-37 MPa normal-strength concrete and were in the range of 50-55 MPa for medium-strength concrete. The percentage deviations in the predicted and measured values were in the range of 3-24% for normal-strength mixes and 0-10% for medium-strength mixes. The model developed in the study for strength-based design of one-part GPC is a significant contribution for concrete practitioners to finalize the mix proportions of concrete as per required applications.