42015-03-31 , 法政大学大学院デザイン工学研究科
The purpose of this study was to reveal volume behaviors and critical limit of concrete cracks of early age concrete. First, the experiments about autogeneous-shrinkage using Thermal Stress Testing Machine (TSTM) and compression creep were carried out to evaluate for volume changes. Then the prediction formulas of each volume changes were generated. And the experiment about tensile characteristics using direct tensile strength tests were carried out. Based on the results, volume changes were estimated individually, and the critical limit for cracking of concrete was investigated under condition of temperature history. As a result, creating the prediction formula of autogeneous-shrinkage which considers zone of stagnation was successful. Also, creating the prediction formula for compression creep which regards applied load as variable was successful. In experiment under condition of temperature history, by evaluating for each volume behaviors individually, superiority was confirmed to evaluate critical limit of concrete cracks by direct tensile strength tests.