Influence of paraffin wax as a self-curing compound in self-compacting concretes

Abstract

Internal curing can be adopted to ensure the availability of water for the hydration of cement, mitigating the adverse effect of water loss to surroundings. The use of self-curing compounds is increasing in the context of the widespread use of self-compacting concrete (SCC) owing to its superior performance in both fresh and hardened states. This paper addresses the effect of using paraffin wax as a self-curing compound in SCC mixes. The variable parameters of the study include curing type, concrete grade (mix proportions), molecular weight and dosage of paraffin wax. Water retention, sorptivity and compressive strength tests were conducted on hardened concretes. The weight loss after 90 d was found to be less in specimens with a self-curing agent than in specimens without. The compressive strengths of the self-cured specimens closely matched those of conventional water-cured specimens. The optimum dosages of light and heavy molecular weight liquid paraffin wax were determined to be 0·1% and 1·0% by weight of cement respectively. It is this concluded that the use of self-curing compounds in SCC facilitates better hydration and thus enhancements in strength and durability properties.