The findings reported in the above studies indicate the likely
effects of OPC inclusion on some mechanical properties of the fly
ash based geopolymers. Generally high curing temperature and
the methods of activation played important roles on the properties
of geopolymers. These observations were mainly based on
geopolymer paste samples and the results cannot be directly
used for concrete since the inclusion of coarse aggregates has
significant effect on the fresh and hardened properties of concrete.
It is also necessary to improve the early age properties of
fly ash based geopolymer concrete cured without applying elevated
heat. This will help reduce the energy and cost associated
with the heat curing of geopolymer concrete. This study aimed to
produce low calcium fly ash based geopolymer concrete suitable
for curing without applying elevated heat. Controlled low dosage
of ordinary Portland cement (OPC) was added with low-calcium
fly ash to study the fresh mixture properties and early age
compressive strength of geopolymer paste, mortar and concrete
samples.