Original paper(Vol.48 No.11 pp.1263)

Experimental study on shrinkage characteristics of high-strength concrete

Kojima Takayuki; Takagi Nobuaki; Matsumura Hideki; Horikawa Satoshi

Abstract:Autogenous shrinkage and drying shrinkage tests were carried out to make clear the shrinkage characteristics of high-strength concrete. Three levels of water-to-cementitious materials ratio (W/(C + SF)) of 20, 30 and 50%, and three levels of silica fume replacement ratio of 0, 7.5 and 15%, were chosen. The shrinkage test with specimens of 10x10x40 cm under the condition of 20 +- 1 degree C and 60 +- 5% RH started at the age of 7 days or 28 days after the measurement of autogenous shrinkage.
The autogenous shrinkage strain was also measured in another specimen until the age of about one year. The autogenous shrinkage strain increased both in its amount and its percentage in the total shrinkage strain with the decrease of W/(C + SF) ratio. Almost the same total shrinkage strain after about one year was observed in the specimens under the drying condition. The difference of the total shrinkage strain by the mix proportion of concrete, and the curing method and period was small.

Key Words:high-strength concrete, autogenous shrinkage, drying shrinkage, silica fume