透水混凝土冻融剥蚀成因分析  

Cause Analysis of Freeze-Thaw Erosion of Pervious Concrete

作　　者：向君正 宋慧 冷梦辉 桂发亮[1] XIANG Junzheng;SONG Hui;LENG Menghui;GUI Faliang(School of Hydraulic&Ecological Engineering,Nanchang Institute of Technology,Nanchang 330099,China;Jiangxi Provincial Key Laboratory of Hydraulic&Civil Engineering Infrastructure Security,Nanchang Institute of Technology,Nanchang 330099,China)

机构地区：[1]南昌工程学院水利与生态工程学院,南昌330099 [2]南昌工程学院,江西省水利土木工程基础设施安全重点实验室,南昌330099

出　　处：《硅酸盐通报》2021年第7期2215-2224,共10页Bulletin of the Chinese Ceramic Society

基　　金：江西省教育厅科学技术项目(GJJ180957);江西省水利重大科技项目(KT201726);国家自然科学基金(41761058)。

摘　　要：为探究透水混凝土冻融剥蚀是否来自水泥浆体劣化,选取2.5~10.0 mm粒径骨料,制备了水灰比为0.31的透水混凝土及同水灰比的水泥石,测量二者冻融循环下质量、强度及透水混凝土相对动弹性模量变化。采用压汞法(MIP)测量水泥石冻融循环下孔结构特征参数及孔径分布变化,并通过扫描电镜(SEM)观察透水混凝土骨料水泥界面形貌演变。结果表明,在水冻与盐冻环境下透水混凝土宏观性能指标均有不同程度下降,骨料水泥界面产生裂缝并随冻融次数增加不断扩展,而水泥石强度、质量及微观孔隙结构均无明显变化。这表明透水混凝土冻融劣化与骨料水泥界面劣化相关。In order to explore whether the freeze-thaw erosion of the pervious concrete comes from the deterioration of cement paste,the aggregate of 2.5 mm to 10.0 mm was selected to prepare the pervious concrete with 0.31 water-cement ratio and the cement paste with the same water-cement ratio.The changes of mass,strength of the cement paste and the pervious concrete,and the relative dynamic elastic modulus of the pervious concrete under freeze-thaw cycles were measured.The characteristic parameters of pore structure and the pore size distribution of the cement paste under freezethaw cycles were measured by mercury porosimetry(MIP).The evolution of aggregate and cement paste interface morphology of the pervious concrete was observed by SEM.The results show that the macro performance indexes of the pervious concrete decrease in different degrees in water freezing and salt freezing environment,and cracks appear at the interface of aggregate and cement paste,and expand with the increase of freeze-thaw times.However,the strength,quality and micro pore structure of the cement paste have no obvious changes.This indicates that the freeze-thaw deterioration of the pervious concrete is related to the interface between aggregate and cement paste.

关 键 词：透水混凝土 水泥石 冻融循环 劣化规律 骨料水泥界面 

分 类 号：TU528[建筑科学—建筑技术科学]