Microfine gound granulated blast furnace slag for high performance concrete

The addition of activated cementitious / pozzolanic materials in high performance concrete is gaining importance in Indian construction industry due to their beneficial effects in improving performance characteristics. In this work, granulated blast furnace slag is activated by mechanical grinding and air cyclone separator to have a defined microfine particle size distribution in the final product called as 'Microfine granulated Blast Furnace Slag'(MFGGBS). A high performance fly ash based concrete (M60) with MFGGBS/ silica fume/ Metakaoline is taken for their relative performance characteristics both in fresh and hardened states. The results indicate that MFGGBS addition in concrete improves cohesiveness, workability and workability retention in fresh state. The long term strength and permeability characteristics are also favourable. To have accrued benefits with MFGGBS, mix proportion is redesigned and trials are carried out to establish MFGGBS as a preferred additive for high performance fly ash based concretes.