Effect of Grinding on Strength and Durability of GGBFS - based Concrete

This paper presents laboratory investigations on the use of ultra fine ground granulated blast furnace slag (UFGGBFS) as a mineral admixture in concrete and cement mortar cubes. Ground granulated blast furnace slag (GGBFS) is available in plenty as a waste product resulting from steel industries and posing disposal problems subsequently leading to environmental problems. GGBFS obtained in the present work was subjected to grinding for two hours using agate pestle mortar and the effect of grinding on size was monitored by testing particle size with the help of a particle size analyzer, where reduction in size was observed. The sample was later used as a partial substitute to cement. A high strength concrete mix with a characteristic compressive strength of 40 MPa was selected for the present study, and cement was replaced with UFGGBFS in three different percentages; namely 3, 5 and 7%. Compressive strength of mortar and strength and sorptivity characteristics of concrete made with UFGGBFS were studied. Test results showed that replacement of cement with 5% UFGGBFS yielded better resistance to compression and sorption in normal and aggressive environments compared to control specimens.