Pervious high-calcium fly ash geopolymer concrete

This study evaluates the properties of pervious concrete made of high-calcium fly ash geopolymer binder. Pervious geopolymer concretes (PGCs) were prepared from lignite fly ash (FA), sodium silicate (NS), sodium hydroxide (NH) solution, and coarse aggregate. The FA to coarse aggregate ratio of 1:8 by weight, constant NS/NH ratio of 0.50, alkaline liquid/FA (L/A) ratios of 0.35, 0.40, and 0.45, and NH concentrations of 10, 15, and 20 M were the PGC mix proportions. The curing temperature of 60 °C for 48 h was used to activate the geopolymerization. The results showed that the high-calcium fly ash geopolymer binder could be used to produce pervious concrete with satisfactory mechanical properties. The relationships of the density-void content, compressive strength-density, and compressive strength-void content of the PGCs were derived and found to be similar to those of conventional pervious concrete.