运用电涡流方法测量混凝土早期收缩,研究了水胶比、引气剂和矿物掺合料等因素对混凝土早期收缩性能的影响.结果表明,水胶比为0.45的混凝土3d收缩率可达到78×10-6,复掺硅灰矿渣和引气剂时,混凝土3d收缩率达到113×10-6;随引气剂掺量增大,混凝土早期收缩增加,但在正常掺量范围内引气剂的影响较小;混凝土成型后400~1500min为水泥水化放热高峰,其早期收缩曲线出现膨胀或收缩减缓现象.
To understand early age shrinkage of concrete in order to get high performance concrete,an eddy current method was used to measure the early age shrinkage of concrete with different water-binder ratios and mineral admixtures such as fly ash,slag and silica fume and air-entraining admixture.The results show that the shrinkage of concrete with water-binder ratio of 0.45 reached 78×10-6 and that of concrete incorporating slag,silica fume and air-entraining admixture reached 113×10-6 in 3 days.Addition of air-e...