复合膨胀剂对高性能混凝土力学行为和收缩开裂行为的影响

Effect of compound expansive agent on the mechanical behavior and deformation behavior of high performance concrete

选取了两种钙镁复合膨胀剂，分别考察了其对C30和C50高性能混凝土力学行为和变肜行为的影响规律，结果表明：膨胀剂外掺时町提高混凝土抗压强度，28d抗压强度增幅为2％～5％；SBTJM-MC（Ⅱ）膨胀剂的湿度敏感性更小，对低水胶比混凝上的干燥收缩补偿效果更优，更适合在高性能混凝土中使用；掺加SBTJM-MC（Ⅱ）复合膨胀剂后混凝上开裂时间显著延长，且初裂宽度显著减小。

Two compound expansive agents were selected to discuss the mechanical behavior and detbrmation behavior of C30 and C50 high performance concrete.The results showed that the compound expansive agent with external mixing raised the compressive strength of high performance concrete,increase amplitude of 28 d compressive strength is 2%-5%;the humidity sensitivity ofSBT JM-MC（ Ⅱ ） is small-er, it can better compensate the drying shrinkage of concrete with low water binder ratio, and it is more suitable for high performance con-crete; concrete with SBT JM-MC（ Ⅱ ） cracked significantly later than reference concrete, and the crack width is significantly smaller too.