Effect of elevated temperature on rice husk ash based self-compacting alkali activated slag concrete mixes under different cooling regimes

Abstract

Abstract Here an attempt has been made to develop self-compacting alkali activated slag concrete mix using Rice Husk Ash as Binder. Investigation on the mechanical properties and residual strength when subjected to temperature of 200,400,600,800°C retention period1hour. The Rice husk ash Self Compacting Alkali Activated Slag Concrete mixes was made with GGBS, Rice husk ash and Lime as the binder, with its content varying from 550 to 650 kg/m3of fresh concrete. The W/B ratio of mixes varied in 0.7-0.88 range. The alkaline solutions had Na2O percentages in the range 5-7 with constant activator modulus maintained at 1. Final mix considered had lower water content, higher percentage of RHA and higher compressive strength. Trails showed Processed Rice Husk Ash30%, lime20% and GGBS50% for binder content 600kg/m3 and 6% Na2O dosage showed greater compressive strength and lower water binder ratio compared to other trail mixes. Results showed the slump flow, L–Box, U-box and V-Funnel as greater than 650mm, 0.85, 20mm and 10s resp. Fire damage of RSAASC was measured by subjecting to elevated temperature between 200-800°C for a retention period of 1hour. Cooled to room using furnace cooling, air cooling and sudden cooling. Results indicated reduced compressive strength with increased temperature.