施工现场高性能混凝土柱早期自收缩试验研究

Early-age autogenous shrinkage experimental study of high performance concrete column under construction-site conditions

使用埋设型KM系列应变传感器成功监测了处于模拟施工现场环境下,高性能混凝土柱早期自收缩变形特性,特别是混凝土浇注后24h的自收缩变形情况。从试验结果看,硬化前后24h高性能混凝土的自收缩变形增长最快,绝对变形值也比较大,24h自收缩值超过14d自收缩变形量的70%;而配筋混凝土试件由于配筋形成的钢骨架对自收缩的约束作用,其自收缩变形小于同等条件的素混凝土试件。监测和分析高性能混凝土结构早期的自收缩变形将对减少结构微裂纹、提高结构的稳定性有重要意义。

The early-age autogenous shrinkage of HPC column under construction-site conditions is monitored successfully, especially the first 24-hour deformation just after casting by KM-100B strain transducer. The experimental results show that HPC autogenous shrinkage rapidly increases within first 24 hours just after HPC casting, and first-day autogenous shrinkage is 70% larger than the total one within 14 days. And the autogenous shrinkage of reinforced specimen is smaller than that of plain specimen due to restraint of reinforcing frame. Monitoring and analyzing early-age autogenous shrinkage of HPC will give significant reference to study the durability and permeability of HPC structures.