Analysis of the effect of curing and mixing periods on mechanical properties of the geopolymer composite

Abstract Geopolymer concrete (GPC) can be substituted for Portland cement concrete because it is cement-free, environmentally friendly, cost-effective, durable, and highly performing. It is an excellent solution for sustainable growth in the building sector. The curing and mixing periods are essential for making homogeneous, compact, or highly dense concrete. The primary aim of this research was to analyze the effect of mixing and curing periods on the physical, chemical, and mechanical characteristics of GPC. The experimental analysis investigated its physical properties, chemical properties, and mechanical properties. After the experimental investigation, it was concluded that the workability and setting time decreased with the increase in mixing time. Regarding chemical properties, the density of GPC specimens reduced as the curing time increased, and it increased as the mixing time increased, although drying shrinkage decreased under both scenarios. For mechanical properties, the compressive strength, splitting tensile strength, flexural strength, and elastic modulus initially increased with the increase in mixing and curing time up to 24 h but decreased significantly afterward. In the analysis of the non-destructive test, the rebound strength and ultrasonic pulse velocity exhibited the same pattern as the destructive mechanical characteristics, with the 24- h curing period achieving the highest point among all other curing times. This research found that the optimum oven curing period for GPC was 24 h for gaining mechanical and chemical properties because the mixing and curing periods play an essential role in gaining strength.