恒温恒湿环境下粉煤灰混凝土表层湿质扩散性能  

Moisture Diffusion in Fly Ash Concrete Surface Layer in Constant Temperature and Humidity Environment

作　　者：鲁彩凤[1] 鲁凤弟[2] 王伟[1] 李允霞 蒋建华[3] 

机构地区：[1]中国矿业大学江苏省土木工程环境灾变与结构可靠性重点实验室,江苏徐州221116 [2]安徽交通职业技术学院土木工程系,安徽合肥230051 [3]河海大学土木与交通学院,江苏南京210098

出　　处：《建筑材料学报》2014年第3期494-500,共7页Journal of Building Materials

基　　金：国家自然科学基金资助项目(50878207;50538070);安徽省高等学校省级自然科学研究项目(KJ2013B071);国家级大学生创新训练项目(201310290013)

摘　　要：在恒温恒湿环境下,通过对粉煤灰混凝土试块进行增湿(正向扩散)、干燥(反向扩散)试验,研究了粉煤灰掺量、微环境条件对粉煤灰混凝土表层湿质扩散的影响,并建立了粉煤灰混凝土等效湿质扩散系数的预计模型.结果表明:在增湿和干燥过程中,粉煤灰混凝土微环境相对湿度响应速率逐渐变缓,湿质扩散系数逐渐减小;在微环境相对湿度相同条件下,15%掺量(质量分数)粉煤灰会使混凝土湿质扩散系数降低,但45%掺量粉煤灰会使混凝土湿质扩散系数明显增大;在粉煤灰混凝土微环境温度和初始内外相对湿度差相同情况下,反向等效湿质扩散系数明显比正向等效湿质扩散系数小.The effects of fly ash replacement and micro environmental conditions on moisture diffusion in fly ash concrete surface layer were studied by humidification test（positive diffusion） and drying test（reversed diffusion） in constant temperature and humidity environment. The predicting model for equivalent moisture diffusion coefficients of fly ash concrete was created. The results show that in the humidification test and drying test, the micro environment relative humidity response rate of fly ash concrete gradually slows down, while the moisture diffusion coefficient decreases gradually; 15%（by mass） fly ash replacement reduces moisture diffusion coefficient of concrete under the same micro environment relative humidity, but 45% fly ash replacement accelerates it. The reversed equivalent moisture diffusion coefficient is significantly smaller than the positive equivalent moisture diffusion coefficient in the same micro environment temperature and initial relative humidity difference inside and outside the fly ash concrete.

关 键 词：粉煤灰混凝土 微环境相对湿度 湿质扩散系数 

分 类 号：TU528.0[建筑科学—建筑技术科学]