MU10再生混凝土承重砌块力学性能与抗冻性试验研究  

Experimental Study on Mechanical Properties and Frost Resistance of MU10 Recycled Concrete Load-Bearing Block

作　　者：齐云鹏 王秋生[1] 秦力[2] 商效瑀[2] QI Yunpeng;WANG Qiusheng;QIN Li;SHANG Xiaoyu(The Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China;School of Civil Engineering and Architecture,Northeast Electric Power University,Jilin 132012,Jilin,China)

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124 [2]东北电力大学建筑工程学院,吉林吉林132012

出　　处：《材料导报》2024年第11期97-103,共7页Materials Reports

基　　金：国家自然科学基金(51708091);吉林省教育厅十三五重点项目(JJKH20200123KJ)。

摘　　要：为进一步提高废弃混凝土利用率,促进严寒地区应用再生混凝土承重砌块,在分析再生骨料物理性能的基础上,考虑了100%再生粗骨料取代率、水胶比、用水量及粉煤灰掺量的影响,采用正交试验设计了C30再生混凝土配合比来制备MU10再生混凝土承重砌块,通过分析MU10再生混凝土承重砌块的力学性能,确定了MU10再生混凝土承重砌块的最佳配合比,利用环境模拟箱验证了MU10再生混凝土承重砌块的抗冻性。结果表明:再生骨料与天然骨料相比表面较粗糙,附着部分旧水泥砂浆,具有低密度,高孔隙率、吸水率和含泥量,压碎指标是天然骨料的两倍左右;MU10再生混凝土承重砌块的最佳配合比为再生粗骨料1 172 kg/m^(3)、天然河砂578 kg/m^(3)、水泥400 kg/m^(3)、粉煤灰100 kg/m^(3)、水150 kg/m^(3),其抗压强度为11.4 MPa,抗折强度为2.1 MPa,可用于承重及有抗震要求的砌体结构;经过50次冻融循环后,MU10再生混凝土承重砌块的质量损失为1.2%、强度损失为18.1%,抗冻性能符合要求,可以作为严寒地区新型墙体材料使用。In order to further improve the utilization rate of waste concrete and promote the application of recycled concrete bearing blocks in severe cold areas, based on the analysis of the physical properties of recycled aggregate, the effects of 100% recycled coarse aggregate replacement rate, water-binder ratio, water consumption and fly ash content were considered, and the mix ratio of C30 recycled concrete was designed by orthogonal tests to prepare MU10 recycled concrete load-bearing blocks. By analyzing the mechanical properties of MU10 recycled concrete load-bearing blocks, the optimal mix ratio of MU10 recycled concrete load-bearing blocks was determined, and the frost resistance of MU10 recycled concrete load-bearing blocks was verified by environmental simulation box. The results show that compared with natural aggregate, recycled aggregate has a rougher surface, with some old cement mortar attached. It has the characteristics of low density, high porosity, water absorption and mud content, and the crushing index is about twice that of natural aggregate. The optimal mix ratio of MU10 recycled concrete load-bearing blocks is 1 172 kg/m^(3) recycled coarse aggregate, 578 kg/m^(3) natural river sand, 400 kg/m^(3) cement, 100 kg/m^(3) fly ash and 150 kg/m^(3) water. Its compressive strength is 11.4 MPa and flexure strength is 2.1 MPa, which can be used for load-bearing and seismic resistant masonry structures. After 50 freeze-thaw cycles, the quality loss and strength loss of MU10 recycled concrete load-bearing block are 1.2% and 18.1%, respectively. The frost resistance meets the requirements, and it can be used as a new wall material in severe cold areas.

关 键 词：再生骨料 再生混凝土承重砌块 配合比 力学性能 抗冻性 

分 类 号：TU522.3[建筑科学—建筑技术科学]