Influence of Cement on Properties of Fly-Ash-Based Concrete

摘要

Fly ash-based geopolymer concrete (FAGC) has been widely recognized in engineering for its environmentally friendly feature. However, the application is limited due to the high-temperature curing condition. This paper attempts to find a measurement to make it possible to cure low-calcium FAGC at ambient temperature. In this study, low-calcium fly ash was substituted with cement by 0, 5, and 10% in weight. One batch of specimens were cured at 176°F (80℃), the other batch of specimens were cured at 68°F (20℃). The acting mechanism of cement was illustrated in terms of slump, compressive strength, and microstructure. The results demonstrated that the optimum use ratio of cement was 5%, which could significantly improve microstructure and the properties of low-calcium FAGC. Additionally, appropriate ordinary portland cement (OPC) content could make it feasible to cure the geopolymer concrete at ambient temperature.