不同二次养护方法对混凝土透气性和孔结构特征的影响

Influence of Secondary Curing Methods on Permeability and Pore Structure Distribution of Concrete

为研究不同二次养护方法对混凝土透气性等性能的影响,设计了4种二次养护方式(空气养护、水养护、标准养护及饱和石灰水养护),测试了养护方式对蒸养混凝土的抗压强度和透气性等性能参数的影响;同时,结合图像处理和扫描电镜技术,分析了混凝土孔结构分布及内部微观结构。结果表明,空气养护下混凝土的抗压强度和水化程度增加速度最慢,性能最差;由于浸出效应,标准养护试件的密实性和抗渗性稍优于水养护和饱和石灰水养护;二次湿养护(标准养护、水养护和石灰石养护)可显著降低蒸汽养护混凝土的大孔占比,使微观结构更加致密。

To investigate the impact of different secondary curing methods on the permeability and other properties of concrete,four kinds of secondary curing methods(air curing,water curing,standard curing,and saturated limestone curing)were designed.The compressive strength and permeability of steam cured concrete were tested under different curing methods.Meanwhile,combining image processing and scanning electron microscopy techniques,the distribution of pore structure and internal microstructure of concrete were analyzed.The results show that the compressive strength and hydration degree of concrete under air curing increase the slowest and have the worst performance.Due to the leaching effect,the compactness and impermeability of standard cured specimens are slightly better than those of water curing and saturated lime water curing.The secondary wet curing(water curing,standard curing,and limestone curing)can significantly reduce the proportion of coarse pores in steam cured concrete,making the microstructure more dense.