Characterization of Gum Arabic As Viscosity Modifying Agent (VMA) for Producing Self-Compacting Concrete (SCC)

Abstract

This study aims at finding alternative indigenous Sudanese material for concrete admixtures that are necessary for casting concrete in hot weather of the Sudan. The objective of this study to classify Gum Arabic (GA) namely, Acacia Senegal (known locally as Hashab Gum) as viscosity modifying admixture (VMA) for lowering powder content in self compacting concrete (SCC). The methodology of the study is based on the European standards BS EN 934-2 & BS EN 480-15 that are used as a paradigm to classify GA as the VMA. Three trial SCC test mixes containing different quantity of cement, namely (400, 370 and 350) Kg/ as powder content. A dose of GA 0.2% by weight of cement is applied after being dissolved in water at a concentration of 30% by water weight. The water/cement ratio (W/C) is kept constant as 0.45 for all mixes. The results of this study showed that the 0.2% GA dosage is appropriate and satisfied all criteria set by BS EN 934-2: 2009 for VMA. Using 0.2% GA as VMA lower the powder of SCC from 400kg to 350kg/ while maintaining the SCC fresh properties.