超强吸水剂对混凝土早期内部相对湿度的影响

Effect of super-absorbent polymers on the internal relative humidity in high performance concrete at early ages

测定了高性能混凝土不同深度处早期湿度随时间的变化,探讨了不同掺量的超强吸水剂(SAP)对不同的外界温湿度条件、不同水灰比的高性能混凝土早期相对湿度的影响。结果表明,与未掺SAP的混凝土相比较,掺SAP混凝土的早期内部湿度有了明显的提高,其内部湿度分布均匀且随龄期的经时变化减小;而且随SAP掺量提高,效果继续增强,尤其是在干热环境以及低水灰比混凝土,SAP的作用更好。结论认为,SAP通过内部引水可以提高混凝土内部的含湿量,改善内部湿度梯度,能够为混凝土提供自养护。

The variations of relative humidity with time at various depths under the exposed face in high performance concrete（HPC） were measured at early ages. The effects of varying amounts of super-absorbent polymers（SAP） on the humidity of HPC with various water-cement ratios as the HPC was cured at two different circumstances were determined. Experimental results show that, in comparison with HPC without SAP, the relative humidity in SAP added HPC was raised, and the distribution of humidity was uniform. These effects were strengthened with the increase of SAP addition and they were eminent in HPC with the low water-cement ratio in the dry hot curing condition. The results suggest that incorporating SAP in HPC can be an effective self-curing method.