Study on the Development of Class C Flyash Based GPC by Ambient Curing

摘要

The fundamental phenomenon of the development of Geopolymer concrete to acheive the early strength is to cure by steam or hot oven curing. As there are practical difficulties in hot curing, few reserchers have tried to cure GPC by exposed or ambient curing methods. Further, most of the works reported on the GPC are based on the low calcium flyash but, only very few on the high calcium flyash. High calcium flyash is more cementitious and less pozzolonic compared to low calcium flyash. Therefore, development of GPC using high calcium flyash as source material is tried, with alkaline solution consisting of the combination of sodium hydroxide and sodium silicate solution having liquid ratio of 2.5. The influence of Molaity of sodium hydroxide in the alkaline solution on the strength properties of three different grades of GPC is studied. Control specimens are cast, cured by ambient curing and tested for compressive strength, splitting tensile strength and modulus of rupture at 28 days of curing. It is observed that the expected 28 day strength of ambient cured GPC can be obtained for specific molarity of NaOH.