混凝土硬化初期的收缩变形试验研究

Experiment about the shrink of concrete in earlier setting

混凝土硬化初期出现的微裂纹容易扩展合并成为宏观裂纹,从而影响工程质量。为分析早期裂纹的成因,采用内埋式应变计对不同强度的混凝土试块进行收缩应变测量,使用半导体应变片改进商品应变计的测量精度。数据结果显示,早期裂纹的主要形成因素并非如人们通常判断的那样是表面失水导致,在终凝以后的一周时间内,混凝土以近似均匀的速度收缩,由此可推断,水泥水化过程中的体积收缩才是混凝土早期裂纹的主因。若根据试验数据有针对性的采取止裂措施,混凝土初期裂纹的防治将建立在更科学合理的基础上。

Microcosmic crackle of concrete which appear in earlier setting spreads into cracking always,and effects structure quality.For search-ing the cause of crackle,writer measure the shrink of concrete test cubes that possess different intensity with buried gauge,and improved the preci-sion of gauge with semiconductor gage.The data discovers that cause of initial crackle not is surface lose water that been regarded common.Con-crete shrinks even within one week after final setting.That concrete shrink is cause of crackle been inproved.If taking suitable measure,cracking could be avoided better.