Effect of Steam Curing on the Properties of High Early Strength Silica Fume Concrete

摘要

Recently, tremendous changes in project delivery methods in construction industry and still way looking towards acceleration of construction works. In this connection FastTrack construction method is current trend in construction industry. In this method, it is challenging task to delivery project at shortest time without compromising on quality and curing. Generally, conventional method of concrete curing need 28 days to be hardened and then can remove formwork however this method delays the project completion and does not holds good in precast construction. In this context, there is need for accelerating curing to attain early strength then can remove formwork early and to reduce the cycle time and increase the formwork repetitions. Henceforth, in this study attempts to attain 50 mm slump and achieve high early strength of 50 MPa at 7 days by adopting steam curing method for silica fume concrete. The concrete mixes were designed according to ACI - 211.4R - 08 and water to cement ratio was set 0.27. Three trail mixes were prepared in different cases one without silica fume, another with silica fume and finally, silica fume with addition of admixture to achieve targeted workability and strength. The results obtained in this study shows that compressive strength achieved 45.16 MPa after 72 hours curing and 51 MPa at 7 days of curing. Moreover, it was important to notice that an increase in the early strength gain due to effect of steam curing and steam curing method affects the ultimate strength of silica fume concrete. Besides, the delay period before steam curing is very essential for the early strength gain.