NO CEMENT CONCRETE: A GREEN SOLUTION TO SUSTAINABLE CONSTRUCTION

Abstract

Concrete without using cement as binder has been the topic of interest for the present day researchers as
cement production is proved to be not environment friendly due to release of lot of carbon dioxide into the
atmosphere. Nearly one ton of cement production releases one tonne of carbon dioxide into the atmosphere.
Researchers have made attempts to use industrial waste products like fly ash, silica fume, ground granulated blast
furnace slag (GGBFS) and rice husk ash as partial replacement to cement in the concrete production. However this
replacement levels are about 25% to 35% only. To further minimise the use of cement in construction industry,
geopolymer binders are developed. Geopolymer concrete is essentially concrete having coarse aggregate, fine
aggregate bonded with alkali activated Fly ash paste. Fly ash is activated by alkali silicate and alkali hydroxide
solution. For the fly alone to be activated by the alkali activator heat curing at 600C for about 24 hours is required. In
present investigation an attempt has been made to use class F fly ash along with GGBFS as source material to develop
alkali activated concrete which can be cured in the room temperature alone. The study includes the casting and
testing of alkali activated concrete using different proportions of source material to alkaline solution ratio, different
concentration of sodium hydroxide solution. The results indicated that the alkali activated concrete can be produced
using GGBFS and Fly ash as source materials and the curing of such concrete at room temperature alone produce
concrete of satisfactory compressive strength