A Basic Study on Autogenous Shrinkage and physical property of the Ultra-High-Strength Concrete

초고강도 콘크리트의 자기수축 및 물리적 특성에 관한 기초적 연구

In ultra-high-strength concrete, autogenous shrinkage is larger than dry shrinkage due to the consume of a large amount of cement and cementitous material, and this is a factor deteriorating the quality of structures. Thus, we need a new technology for minimizing the shrinkage strain for ultra-high-strength concrete. So, this paper have prepared super-high-strength concrete with specified mixing design strength of over 150MPa and have evaluated a method of reducing autogenous shrinkage by utilizing expander and shrinkage-reducing agent. According to the results of this study, with regard to the change in length by autogenous shrinkage, an expansion effect was observed until the age of seven days. The expansion effect was higher when the contents of the expander material were higher. In addition, ultra-high-strength concrete showed a shrinkage rate that slowed down with time, and the effect of the addition of expander material on compressive strength was insignificant. That is shown that required more database to be accumulated through experimental research for the shrinkage strain of members.