Effect of coarse aggregate size on the compressive behaviour of geopolymer concrete

Abstract

The utilisation of ordinary Portland cement not only consumes significant amount of natural resources but also causes pollution to the environment due to Carbon emission. As a result, a replacement material for cement including the use of fly ash becomes a solution to this environmental concern. Accordingly, the compressive strength of cement-based concrete depends primarily on several factors such as the size of gravel. Therefore, it is worth studying to find out whether this factor likewise influences the compressive behaviour of geopolymer concrete. This study experimentally investigated the effect of the particle size of coarse aggregate on the compressive behaviour of fly ash geopolymer concrete. Compressive tests have been carried out on a 100 mm × 200 mm cylindrical specimen using a compression testing machine. The results showed that the fly ash geopolymer concrete specimens exhibited brittle failure mode characterised by splitting, shear, columnar and conical type of failure. It was found that the size of the coarse aggregate that offered a maximum compressive strength is in the range of 12.5–25 mm. Furthermore, the size of the coarse aggregate does not affect the trend results on ambient vs. oven-cured specimen, as well as the days of curing.

Keywords:

• Geopolymer concrete
• compressive strength
• coarse aggregates
• oven-cured specimen