Arriving the optimum retarder dosage level of sugar on the setting time, compressive strength, and microstructure property of Portland pozzolana cement

Abstract

Cement and concrete are the most crucial and dominating engineering materials in the construction sector. Cement serves as an excellent binder for concrete and when it is treated under unusual conditions either to satisfy accelerating or retarding requirements by the construction industries, admixtures role comes into the effect. The construction industry has been searching for retarding admixtures and the optimal dosage level, particularly for ready mix concrete applications. Generally the retarding admixtures such as organic retarders (lignosulphonates, hydroxycarboxylic acids and their salts, phosphonates, sugars) or inorganic retarders (phosphonates, borates) were generally used to reduce the speed of the reaction between cement and water by altering the growth of the hydration products and/or limiting the rate of water penetration to the cement particles. The research was still in its infancy stage in terms of determining not just the appropriate dosage amount, but also the ideal retarder materials for the aforementioned uses. In considering this industrial need, an attempt was made on utilizing the usage of sugar in the concrete to study the retarding effect without affecting the strength properties of cement. The sugars usage levels were at 5, 10, 15, and 20% of the usage of cement to investigate consistency, setting time, compressive strength and micro structure properties at the curing age of 7, 14 and 28 days on the mortar specimens. The conclusions of the study reported that setting time was extended with increase of the dosage levels of sugar. However in considering the strength property, less than 5% of sugar dosage level can be better for the application as retarding agent in the industry applications.