The Impact of Sugar on Setting -Time of Ordinary Portland Cement (OPC) Paste and Compressive Strength of Concrete

Abstract

Construction activities are accomplished through laid down procedures and parameters such as temperature and humidity. Concreting in hot weather above 100°F accelerates the early hydration of cement and produce concrete with high strength at early ages but later, the strength is reduced considerably. The rapid evaporation of water causes plastic shrinkage in concrete and subsequent cooling cause tensile stresses and cracking. The study seeks to investigate the impact of sugar on setting -time of ordinary Portland cement (OPC) paste and compressive strength of concrete. Sugar used for the experiment was sucrose crystals (C₁₂H₂₂O₁₁); it was dissolved in required amount of water. The sugar was used at concentrations of 0, 0.05, 0.06, 0.08, 0.10, 0.20, 0.40, 0.60, 0.80, and 1% by weight of cement. In addition, the compressive strength of the concrete was investigated at 3, 7 and 21 days. Sugar crystals (C₁₂H₂₂O₁₁) were weighed and dissolved in the required 0.6 volume of water before mixing. The materials were batched by weight and mixed manually. The increases in initial and final setting times were apparent to sugar content of 0.06%. Reduction in setting times begins from 0.08% sugar content and flash setting occurs from 0.2% to 1%. There was no correlation between the speed of setting of cement paste and strength gain from sugar level of 0.08 to 1%. Strength gain peaks at 0.05% sugar content at 3 days and at 0.06% sugar content at 7, and 28 days respectively. Sugar delays the setting time of cement by up to 1.33 hours at dosage level of 0.06% by weight of cement. No effect on workability, compaction by the use of sugar as admixture in concrete. Higher long-term compressive strength can be achieved in concrete by the use of sugar as admixture. The study recommends that sugar should be used as a retarder but when it is used in excessive amount it reverse its property. The quantity of the sugar and other related quantities must be adequately metered in the production process.

Keywords: Concrete, Compressive Strength, Ordinary Portland Cement, Sugar and Setting-Time