Experimental study of accelerating early age concrete strength under elevated temperature, steaming, and chemical admixture addition of normal and high strength concrete

Conventionally, curing is performed by moisturizing concrete periodically when the fresh concrete is still undergoing chemical reaction processes. This study is focused on early age concrete strength treated with special curing of early heating treatment and steaming. The addition of chemical accelerator and normal curing are also examined. Tests were conducted on normal and high strength concrete specimens. Treatments of the test specimens with steaming and early heating were carried out for 3 and 8 hours, respectively, at a temperature of about 70 degrees C. Test results showed that concrete compressive strengths gained in 3-days compared to 28-days under normal curing, chemical accelerator, steam curing, and elevated temperature curing were 39%, 50%, 64% and 59%, respectively. While in 7-days were 66%, 75%, 80% and 83%, respectively. And in 14-days were 87%, 91%, 93% and 93%, respectively. For high-strength concrete, the compressive strengths gained in 3-days were 37%, 62%, 68% and 71%, respectively. The strengths in 7-days were 65%, 77%, 83% and 82%, respectively. And in 14-days were 85%, 89%, 90% and 93%, respectively. Test results indicated that the additions of chemical accelerator, steam and elevated temperature curing in order to obtain the high early age concrete strengths are highly recommended.