Investigating the influence of adding different sugar ratios on cement paste hydration and behavior

In the current research, hydration and setting behaviors of cement paste are investigated in the presence of sugar as a concomitant retarder and accelerator. OPC and Sugar, as a retarder were mixed at 0, 1, 1.5 and 2 % by weight of cement respectively with water to cement ratios of 0.35, 0.32, 0.30, 0.28 and likewise at 26 %. Setting time was measured with a Vicat and hydration heat was monitored by means of thermocouples. It was found that the optimal 1 % sugar content can delay the final setting time by approximately 350 min at w/c = 0.35, and this value is significantly higher than those documented in literature, indicating that sugar is an effective and inexpensive retarder demand. Meanwhile, the proper dosage at w/c = 0.32 advanced the initial setting time to 172 min, which also proved that sugar delayed early hydration. Results of the heat hydration analysis revealed for the solution 1.5 % sugar and w/c of 0.30 that a maximum temperature of 33.89 with difference higher than control up to 3.3 °C, which showed that there is interrelation between dosage and thermal kinetics. Also, the bleeding and surface cracking were decreased by sugar which contributed to the one with a better microstructural significance as well as smoother paste faces.