- Thermal curing has significant effect on transport properties of low calcium FA-based GPC.
- Optimum thermal curing for FA-GPC is found to be oven curing at 75 °C for 18–24 h.
- Proper thermal curing reduces the porosity and sorptivitycoefficient of FA-GPC.
- Proper thermal curing increases the compressive strength and electrical resistivity of FA-GPC.
- Thermal curing reduces the surface and bulk resistivity of Portland cement concrete.
The aim of this study is to evaluate the transport properties of class F fly ash-based geopolymer concrete cured at various conditions. Twelve different heat curing regimes including three temperatures of 60, 75 and 90 °C and four curing durations of 8, 12, 18 and 24 h, as well as ambient curing, were imposed to the specimens. The material properties such as compressive strength, elastic modulus, ultrasonic pulse velocity, absorption, volume of permeable voids, pore size distribution and resistivity were evaluated against the reference Portland cement (OPC) concrete. Experiments showed that proper curing conditions such as curing at 75 °C for 18–24 h yield a geopolymer concrete with low volume of permeable voids and low sorptivity coefficient. The reduced volume of permeable voids and less continuous capillaries, attained by applying the proper curing regime, leads to an increased electrical resistivity and compressive strength of the low-calcium fly ash-based GPCs.