STUDY ON THE MODEL CONSTRUCTION FOR PREDICTING THE EXPANSION BEHAVIOR OF CONCRETE USING EXPANSIVE ADDITIVES

In this study, to construct an expansion prediction model for expansive additive (EA), we conducted experiments to obtain the basic properties of EA-mixed cement paste using ettringite quicklime complex (CSA type) EA. For cement pastes with EA replacement ratio of 2.6 to 12.9%, expansion strain measurements and some mechanical tests were performed to construct model functions. In addition, the state of EA after hydration was observed using a micro-CT scanner and a scanning electron microscope. From test results, we confirmed that the hydration mechanism of EA changes when the replacement ratio exceeded 6.4%.