风积沙轻骨料混凝土冻融损伤及寿命预测研究  

Study of the freezing-thawing damage and life prediction of aeolian lightweight aggregate concrete

作　　者：董伟[1] 申向东[1] 赵占彪[1] 何静[1] 俞婷婷[1] 

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,内蒙古呼和浩特010018

出　　处：《冰川冻土》2015年第4期1009-1015,共7页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(51569021);高等学校博士学科点专项科研基金项目(20121515110002);内蒙古自治区自然科学基金项目(2013MS0720);内蒙古自治区科技计划应用与研究开发项目(20130425);内蒙古自治区教育厅高等学校研究项目(NJZY12O75)资助

摘　　要：基于浮石轻骨料混凝土为基础,将不同质量的风积沙作为细骨料替代部分河砂,研究风积沙轻骨料混凝土冻融损伤机理及服役寿命.通过室内快速冻融循环试验,定量分析风积沙轻骨料混凝土的抗冻耐久性能.在整个冻融循环期内,相对动弹性模量的变化规律可分为直线下降阶段、直线+曲线下降阶段、曲线下降阶段.以此为基础,建立轻骨料混凝土直线和曲线双段式相对动弹性模量衰减方程,依据5组混凝土的抗冻试验结果对方程进行了验证,并预测其在西部地区的服役寿命.结果表明:直线和曲线双段式的相对动弹性模量衰减方程能够准确的反应混凝土冻融损伤劣化规律.风积沙最优替代率为20%,可以满足25 a的使用寿命.损伤模型可为沙漠地区混凝土使用提供一定的理论依据.In this paper,taking pumice lightweight aggregate concrete as basis and taking different aeolian sands as fine aggregate to replace part of river sand,freezing-thawing damage mechanisms and service life of the aeolian sand light weight aggregate concrete were investigated. Antifreeze durability of aeolian sand pumice lightweight aggregate concrete was investigated through freezing-thawing cycle test at various ambient temperatures.In the whole freezing-thawing cycle period,the relative dynamic elastic modulus has straight line decline phase,straight line plus curve downward phase and curve decline phase,which became the basis of establishing a double segments( a straight one and a curve one) of relative dynamic elastic modulus attenuation equation. Besides,the equation was verified and the concrete lifetime in West China was predicted according to five tests of freezing-thawing cycles. Results demonstrated that the double segments of relative dynamic elastic modulus attenuation equation could accurately describe the variation of concrete freezing-thawing damage. What's more,the optimal substitution rate of aeolian sand was 20%,the lifetime of aeolian sand pumice lightweight aggregate concrete could meet the application for more than 25 years. The damage model is a theoretical basis for applying concrete in desert areas.

关 键 词：浮石轻骨料混凝土 风积沙 衰减方程 服役寿命 冻融损伤 

分 类 号：TU528[建筑科学—建筑技术科学]