高强轻集料混凝土干缩变形性能研究

Research on Property of Drying-shrinkage Deformation of High-Strength Lightweight Aggregate Concrete

研究了低吸水率高强页岩陶粒配制的高强轻集料混凝土(HSLC)的干缩变形性能及其影响因素。研究结果表明:通过降低轻集料含量和减小最大粒径的方式来提高轻集料混凝土强度对混凝土的干缩变形有明显不利影响;预湿处理对采用低吸水率陶粒HSLC的干缩变形仍有一定的抑制作用;水灰比对HSLC干缩变形的影响呈非线性关系,存在临界水灰比使混凝土收缩变形最大,试验测得的临界水灰比为0.45;水泥用量较低时,HSLC干缩变形对水泥用量增加敏感,当水泥用量接近临界用量时,其敏感性大大降低。

The drying shrinkage deformation property and influence factors of HSLC prepared from shale ceramiste with low water absorption and high strength are studied. The results show that it has a bad effect on the dryingshrinkage deformation of concrete to achieve high strength by reducing the content of lightweight aggregates or reduc ing maximum size of lightweight aggregate. Pre-wetting can still reduce the drying-shrinkage deformation of HSLC caused by ceramiste with low water absorption. It is the nonlinearity relationship between the water to cement ratio and drying-shrinkage deformation of HSLC. There exists a critical W/C ratio at which the drying-shrinkage deformation is the biggest. The critical W/C ratio is 0. 45 in this paper. The drying-shrinkage deformation is sensitive to the cement content when the cement content is lower, but the sensitivity decreases obviously when the cement content reaches to the critical content.