Alkali activated Cement binders fly ash /slag /metakaolin or combination thereof has been a topic of extensive research and numerous publications have been made world over on this with studies reported for various alkali activators.
At the authors labs some initial investigations indicated the possibility of high early clinker-less cement/cement binder, further experimentation carried out indicated that the early strengths of alkali activated slag based cement mortars was primarily a function of nature and concentration of the alkali activators used and fineness of the slag used, the effect of curing temperature on the early strengths was not observed to be substantial. Some investigations were also carried out with alkali activated slag +fly ash mix binders to assess the effect on early strengths but use of different fineness of low lime class F fly ash.
The paper discusses the results of these investigations in some details, which include effect of nature and type of alkaline activator, effect of fineness of slag and fly ash used on the early strengths of the clinker – less Cement Mortars.
The paper further discusses the mortar and concrete properties of selected Alkali activated slag/Fly ash cement, in terms of Water permeability, chloride permeability etc and compares the observed properties of concrete with similar grade concrete made with OPC/ PPC and PSC concrete in terms of strength development as well as microstructure development and different hydration products formed at 28 days.
Authors finally concludes that very high early strength cementitious binder could be developed having superior strengths as well as durability properties compared to existing cements in the Indian market. The paper was presented and published at 15th NCB Int Seminar