Effect of Aggregate Type and Size on the Fresh Properties of Self-Consolidating Geopolymer Concrete

The effects of aggregate type and size on the fresh characteristics and strength gains of ambient-cured self-consolidating geopolymer concrete (SCGC) were investigated in the present study. SCGC was made from three different types of aggregates: crushed gravel, crushed marble, and a combination of both. In addition, several aggregate sizes (9 mm, 12 mm, and 16 mm) were also examined. The first group included 100% ground granulated blast furnace slag (GGBS), whereas the second group included 50% GGBS and 50% fly ash (FA). Slump flow, L-Box, and V-funnel tests were used to conduct fresh state tests, whereas compressive strength improvements were investigated at ages of 7 days, 14 days, 28 days, and 90 days. The results indicated that, regardless of aggregate type, aggregate size had a significant effect on fresh state characteristics. The optimal size of aggregate was 12 mm and crushed gravel showed optimum performance when compared to other types of aggregate and mixing. However, aggregate had a considerably lower effect on fresh characteristics than basic materials, and using fly ash significantly improved fresh properties. The improvement was about 5/, 10, and 60% respectively for both type/size of aggregate and the use of fly ash. Moreover, the base materials and aggregate types sufficiently affected the compressive strength of SCGC at different ages. The improvement was determined to be 8, 15, and 50% respectively for both the type/size of aggregate and the use of 100% GGBS. It was revealed that the compressive strength of SCGC in an ambient environment had a superior improvement at the age of 90 days in comparison to the age of 7, 14, and 28 days.