冻融循环后再生混凝土的力学性能及损伤模型研究  

Research on Mechanical Properties and Damage of Recycled Concrete After Being Subjected to Freeze-Thaw Cycles

作　　者：王晨霞 张铎 曹芙波 吴亚轩 叶昌 李兰 WANG Chenxia;ZHANG Duo;CAO Fubo;WU Yaxuan;YE Chang;LI Lan(Inner Mongolia University of Science and Technology School of Civil Engineering,Baotou 014010,China;Inner Mongolia Autonomous Region Construction Industry Association,Hohhot 010020,China;Beijing Urban Constitution Road&Bridge Group Co.Ltd.,Beijing 100124,China)

机构地区：[1]内蒙古科技大学土木工程学院,内蒙古包头014010 [2]内蒙古自治区建筑业协会,呼和浩特010020 [3]北京城建道桥建设集团有限公司,北京100124

出　　处：《工业建筑》2022年第5期199-207,共9页Industrial Construction

基　　金：国家自然科学基金(51868061);内蒙古自然科学基金(2020MS05071)。

摘　　要：通过改变冻融循环次数,研究了普通混凝土和粗骨料取代率100%的再生混凝土力学性能及抗冻性能的影响规律,以抗压强度损失率、质量损失率和动弹性模量损失率作为损伤变量建立冻融损伤模型,并针对内蒙地区对再生混凝土抗冻性进行寿命预测。研究结果表明:再生混凝土的抗压强度和劈裂抗拉强度与冻融循环次数呈反比关系,冻融循环每增加50次,抗压强度平均下降33.1%,劈裂抗拉强度平均下降33.0%;在冻融前期,普通混凝土与再生混凝土力学性能相差不大,但随着冻融次数的增加,二者性能均出现劣化且再生混凝土劣化程度大于普通混凝土,根据动弹性模量损失率建立的冻融损伤模型拟合精度更高,冻融损伤模型的建立可以直观清晰地反映再生混凝土宏观的力学性能变化。In order to study the effects of recycled concrete with 100%replacement rate of coarse aggregate and common concrete on mechanical properties and frost resistance,an experimental study was conducted by changing the number of freeze-thaw cycles.The freeze-thaw damage model was established by analyzed loss rate of compressive strength,mass and dynamic elastic modulus,and also aimed at the anti-freeze durability lives of recycled concrete was predicted for the Inner Mongolia area.The result of research shows that the compressive strength and splitting tensile strength of recycled concrete was inverse to the number of freeze-thaw cycles.For every 50 additional freeze-thaw cycles,the average compressive strength decreased by 33.1%,and the average splitting tensile strength decreased by 33%.In the early stage of the freezing and thawing,the ordinary concrete and recycled concrete anti-freeze performance were similar,but the performance degradation and the recycled concrete degradation are greater than ordinary concrete with the increase of freeze-thaw cycles.The establishment of freeze-thaw damage model can intuitive clearly reflect the mechanical properties of recycled concrete macroscopic changes because of the higher fitting accuracy of dynamic modulus of elasticity loss of freeze-thaw damage model.

关 键 词：再生混凝土 力学性能 冻融循环试验 冻融损伤模型 

分 类 号：TU528[建筑科学—建筑技术科学]