THE EFFECT OF SEASHELL WASTE ON SETTING AND STRENGTH PROPERTIES OF CLASS C FLY ASH GEOPOLYMER CONCRETE CURED AT AMBIENT TEMPERATURE

The main issue of fly ash-based geopolymer concrete is the need for heat curing treatment. The use of a material with a high calcium content is assumed to be able to resolve this problem. This paper reports the effect of seashell waste on setting time and strength properties of Class C fly ash geopolymer concrete cured at ambient temperature. Geopolymer concrete was prepared by using high calcium Class C fly ash activated by activator solution. A proportion of seashell waste was added with fly ash to accelerate the curing at ambient temperature instead of using heat curing. The setting time and strength properties were calculated by Vicat, slump, and compressive strength tests. The result shows that the highest compressive strength was achieved by geopolymer concrete with 10% seashell waste addition and exhibited a comparable strength to that normal concrete. The 10% seashell waste addition also increased the setting time, which affected the strength of geopolymer concrete. It can be suggested that the seashell waste inclusion with Class C fly ash improves the performance of geopolymer cured at ambient temperature.