Cementing material from calcium carbide residue-rice husk ash

This paper proposes a new cementitious material from a mixture of calcium carbide residue and rice husk ash. Calcium carbide residue and rice husk ash consist mainly of Ca(OH)(2) and SiO2, respectively. The cementing property was identified as a pozzolanic reaction between the two materials without portland cement in the mixture. Properties such as setting times of pastes, flow, and compressive strength of mortars were investigated when calcium carbide residue and rice husk ash were used as cementitious material. The results show that the setting times of the new cementing pastes are longer than that of the portland cement paste. The ratio of calcium carbide residue to rice husk ash of 50:50 by weight obtains the highest compressive strength of mortar. The compressive strength of mortar could be as high as 15.6 MPa at curing age of 28 days and increased to 19.1 MPa at 180 days. According to the compressive strength of mortar, the mixture from calcium carbide residue-rice husk ash has a high potential to be used as a cementing material. However, more research and development especially on optimum mix design, setting times, early strength, and durability of concrete should be carried out.