Abstract:
This study represents a comparison of five SCP systems with and without SRMs made at the water demand of cement and those made at individual water demands of SCP systems having varying acacia Nilotica (AN) gum powder content, the latter approach has already been published and has been used here to illustrate the difference in response. The objective of the comparison was to see the response differences due to difference in mixing water content, and to come out with some optimized systems. SCP systems were studied in both fresh and hardened states for parameters including Vicat water demand, super-plasticizer demand, flow characteristics, Compressive strengths, and shrinkage study of SCP systems. AN gum powder was characterized first using NMR and FTIR techniques and it consisted of proteins and carbohydrates. Acacia Nilotica (AN) gum was obtained from a local tree locally known as ―keekar‖. It was found that setting times of SCP systems was quite delayed. Linear early shrinkage got reduced with the incorporation of increased AN powder content, and compressive strengths at the age of 3, 7, 14 and 28 days were reduced by 15% to 20% which can be offset by using suitable SRMs. Accelerator was used to reduce the elongated setting time. Initial and final setting time for 0.66% AN gum content, get reduced to 1 hour and 4 hours respectively. Addition of accelerator also showed 43% increase in the compression strength for 0.66% AN gum content in the SCP.
