基于温度-应力试验的再生混凝土抗裂性能研究  

Study on crack resistance of recycled concrete based on temperature-stress test

作　　者：王晨飞 马恺泽[2] 侯炜[3] 刘昌钧 李志勇 WANG Chenfei;MA Kaize;HOU Wei;LIU Changjun;LI Zhiyong(School of Civil Engineering&Architecture,Xiamen University of Technology,Xiamen,Fujian 361024,China;School of Architecture and Engineering,Chang'an University,Xi'an,Shaanxi 710061,China;College of Civil Engineering,Huaqiao University,Xiamen,Fujian 361024,China;Xiamen Z.Y.X Building Materials Co.,Ltd.,Xiamen,Fujian 361105,China)

机构地区：[1]厦门理工学院土木工程与建筑学院,福建厦门361024 [2]长安大学建筑工程学院,陕西西安710061 [3]华侨大学土木工程学院,福建厦门361024 [4]厦门中永翔建材有限责任公司,福建厦门361105

出　　处：《福州大学学报（自然科学版）》2023年第2期250-255,共6页Journal of Fuzhou University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51878583);福建省中青年教师教育科研项目(JAT190648);厦门市建设科技项目(XJK-2021-1-11)。

摘　　要：通过预湿法和净浆裹石法对再生骨料进行预处理,采用温度-应力试验方法研究绝热温升模式和100%约束条件下再生混凝土的温升、应变、徐变和约束应力,分析不同预处理再生骨料方式对再生混凝土早期抗裂性能的影响.结果表明:预湿法(RAC-P)和净浆裹石法(RAC-C)可有效改善再生骨料的吸水和返水现象.净浆裹石法可有效调控再生混凝土的放热行为,有助于降低混凝土的温升.升温阶段,约束峰值压应变分别为普通混凝土组的9.95倍和16.52倍,净浆裹石法预处理再生骨料试件的受压徐变增长更快,获得的压应力储备更大.降温阶段,RAC-C组和普通混凝土组的约束峰值拉应变分别为RAC-P组的1.39倍和1.34倍,所有再生混凝土试件的受拉徐变变化速率接近.对比发现净浆裹石预处理方法可较好地改善再生混凝土的早期抗裂性能.Two kinds of different pretreatment methods i.e pre-wet and steep liquor wrapped stone craft were adopted to treat the recycled coarse aggregate,and the temperature-stress testing method was used to study the temperature rise,strain,creep and restraint stress of the recycled concrete under 100%restraint.The effect of different pretreatment methods on the early crack resistance of recycled concrete was analyzed.The results show that the pre-wet method(RAC-P)and steep liquor wrapped stone craft method(RAC-P)can effectively improve the excessive water absorption and water return of the recycled aggregate.Steep liquor wrapped stone craft can effectively control the exothermic behavior of recycled concrete and help reduce the temperature rise of concrete.In the heating stage,the restrained peak compressive strains were 9.95 times and 16.52 times that of the ordinary concrete group.The compressive creep of the recycled aggregate specimens pretreated by steep liquor wrapped stone craft increased the fastest,and the obtained compressive stress reserve was the largest.In the temperature reduction stage,the restrained peak tensile strains of the RAC-C group and the ordinary concrete group are 1.39 times and 1.34 times that of the RAC-P group,respectively.The tensile creep rate of all specimens was similar.Through comparison,it is found that the early crack resistance of recycled concrete can be better improved by the pretreatment of aggregate recycled with steep liquor wrapped stone craft.

关 键 词：再生混凝土 预湿法 净浆裹石法 温度应力试验 绝热温升 抗裂性能 

分 类 号：TU528[建筑科学—建筑技术科学]