高强混凝土的干缩及自收缩性能研究

设计6种不同配合比及3种养护条件实验研究了水灰比、矿物掺合料和养护条件对混凝土干缩及自收缩性能的影响。结果表明,混凝土的自收缩率随水灰比（w/c）降低而提高,当w/c由0.50降低到0.23时,90 d自收缩率由64×10-6提高到441×10-6,提高了近7倍,显示出高强混凝土具有显著的自收缩特点。掺入硅灰将增大高强混凝土的自收缩率,密封养护和暴露养护时高强混凝土收缩率无明显区别。从整体干缩性能看,高强混凝土和普通混凝土之间无明显差别。

Drying Shrinkage and Self-Desiccation of High Strength Concrete

An experiment was undertaken to study the drying shrinkage and self desiccation of concrete.The test results show that the self desiccation of concrete increases as water to cement ratio decreases.The 90 d self desiccation increases from 64×10-6 to 441×10-6 when the w/c decreases form 0.50 to 0.23 due to the consume of water caused by the cement hydration.Incorporation of silica fume increases the self shrinkage of high strength concrete.However the drying shrinkage of high strength conctete is similar to the normal strength concrete.