混凝土的毛细吸水特性及其与孔结构的关系  

CAPILLARY WATER ABSORPTION CHARACTERISTICS OF CONCRETE AND ITS RELATIONSHIP WITH PORE STRUCTURE

作　　者：郭秋生 GUO Qiusheng(Beijing College Finance and Commerce,Beijing 101101,China)

机构地区：[1]北京财贸职业学院,北京101101

出　　处：《工业建筑》2020年第3期119-123,共5页Industrial Construction

基　　金：国家自然科学基金项目(51278039)。

摘　　要：为了更好地理解混凝土的毛细吸水特性,研究了不同混凝土种类、钢纤维掺量、养护条件对混凝土溶液吸入量的影响,给出了毛细吸水系数,分析了孔结构与毛细吸水系数的关系。结果表明:不同混凝土(损伤与未损伤) 15~180 min和180~480 min两阶段溶液吸入量均与t1/2呈线性关系;超高性能混凝土(UHPC)的毛细吸水系数远小于高性能混凝土(HPC);随着钢纤维掺量的增加,UHPC的溶液吸入量和第一阶段毛细吸水系数均增大;未水化胶凝材料再水化作用影响下,水中养护UHPC的720 d溶液吸入量略大于自然养护的;毛细吸水系数主要受到100~3 nm范围内孔含量的影响,且第一阶段毛细吸水系数随其含量增加而增大;考虑孔隙率的影响下计算累积毛细吸水高度,其计算结果与实际相符。In order to better understand the capillary water absorption characteristics of concrete,the influence of different types of concrete,steel fiber content,and curing conditions on the solution absorption amount were studied in the paper. The capillary water absorption coefficients were also obtained. Moreover,the relationship between pore structure and capillary water absorption coefficient was analyzed. The results showed that the two stages,15 ~ 180 min and 180 ~ 480 min,of solution absorption amount of different types of concrete (damage and undamaged) were linear with t1/2. The capillary water absorption coefficient of ultra-high performance concrete (UHPC) was much smaller than that of high-performance concrete (HPC). With the increase of the steel fiber content,the solution absorption amount of the first stage and the capillary water absorption coefficients of UHPC both increased. Under the influence of rehydration,the solution absorption amount of UHPC specimens cured in water was slightly larger than that cured in the room condition at the age of 720 d. The capillary water absorption coefficient was mainly affected by the pore content in the range of 100 ~ 3 nm,and the capillary water absorption coefficient in the first stage increased with the increase of its content. Considering the influence of porosity,the cumulative capillary water absorption height was calculated,and the calculation results were in accordance with the actual situation.

关 键 词：超高性能混凝土 溶液吸入量 钢纤维掺量 孔结构 

分 类 号：TU528[建筑科学—建筑技术科学]