Using Gum Arabic as Viscosity Modifying Agent with Natural Pozzolana in Producing

Abstract

Development of SCC in Sudan is highly needed to overcome many problems in the construction sector. The elimination of vibration for compacting concrete during placing through the use of SCC leads to better homogeneity, enhancement of working environment and improvement in the productivity. This research presents experimental investigation on introducing the technology of self-compacting concrete (SCC) in the hot climate of Sudan using local materials. In this experimental work, SCC was made by the usual ingredients cement, fine aggregate, coarse aggregate and water plus Natural Pozzolana and Gum Arabic .Natural Pozzolana is used for replacement of cement and Gum Arabic as viscosity modifying agent VMA. Six mixes containing Natural Pozzolana as 10% replacement of cement with (0,1.5,2,3,7,10) percentages of Gum Arabic were used to investigate the possibility of obtaining acceptable fresh properties of SCC. The European Guidelines for Self Compacting Concrete were used to define and check SCC properties and tests. A control mix with zero Pozzolana and zero Gum Arabic was also used for comparison. According to these guidelines mixes (1,2,3) which contained 0.0%,1.5% and 2.0% of Gum Arabic respectively did not match SCC standard and properties. But mix (4) which contained 3% of Gum Arabic was found to be the most acceptable and suitable mix for SCC. Mixes (5,6) which contained 7% and10% of Gum Arabic respectively had acceptable slump flow but their cubes compressive strength results were very low . The research concludes that 3% Gum Arabic as VMA and 10% Pozzolana Replacement produces SCC.