矿物掺合料对混凝土早期开裂性能的影响  

Effect of the Mineral Blenders on the Early-Age Cracking Behaviors of Concrete

作　　者：王雪芳[1] 郑建岚[1] 晁鹏飞[1] 

机构地区：[1]福州大学土木工程学院,福建福州350002

出　　处：《中国矿业大学学报》2007年第6期768-772,804,共6页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(50478003);福建省自然科学基金重大项目(2002F007)

摘　　要：为了研究粉煤灰、矿渣掺量及其复掺比例对混凝土早期约束开裂性能的影响,本文采用改进的平板法进行混凝土早期约束开裂性能的试验研究,同时结合水分蒸发量和电阻率试验进行混凝土开裂性能研究分析.结果表明:粉煤灰与矿渣对混凝土的开裂性能作用存在一最佳掺量分别为45%和40%,但当掺量分别超过60%和50%时,其开裂性能又迅速下降;粉煤灰与矿渣复掺能提高混凝土的开裂性能,粉煤灰与矿渣等比例复掺时其开裂性能最佳;同时,混凝土的开裂时间与其电阻率最低值之间成非线性关系.To study the influence of the content of fly ash and slag and the proportions of slagfly ash on the early-age restraint cracking behaviors of concrete, the cracking behaviors of concrete was analyzed combining the test of the evaporation capacity and electrical resisitivity of the concrete using the modified flat-type specimen. The results show that the optimal content of fly ash and slag are 45% and 40% of binder, respectively. Under the conditions of the optimal content, the early age cracking behaviors of concrete is higher than other content. But .when the content of fly ash exceeds 60% of binder and that of slag exceeds 50% of binder, the cracking behaviors of concrete rapidly decrease. The cracking behaviors of the concrete mixtured with the fly ash and the slag is higher than that only with the fly ash or with the slag. And the cracking behaviors of concrete with 1 ： 1 of the proportions of slag-fly ash is the best. The relationship between the cracking time and the lowest value of electrical resistivity of concrete is nonlinear.

关 键 词：混凝土 开裂 粉煤灰 矿渣 电阻率 水分蒸发 

分 类 号：TU528.53[建筑科学—建筑技术科学]