摘要
近年来,城市的快速发展导致了大量建筑垃圾的产生和排放,从建筑垃圾中制取再生骨料并加以利用,可以有效缓解建筑垃圾填埋带来的坏境问题,符合我国低碳环保、可持续发展的基本国策。再生骨料表面附着的旧砂浆具有高孔隙率、高吸水率等特点,不仅使再生混凝土的密实度大大降低,还会影响水泥的水化进程,对再生混凝土的力学性能产生不利影响。由于旧砂浆的存在,再生混凝土较普通混凝土有更复杂的界面过渡区。本文总结了部分学者关于再生混凝土界面过渡区的微观研究,揭示了新、旧骨料砂浆界面过渡区对再生混凝土抗压性能的影响。同时从宏观因素(如再生骨料取代率、再生骨料来源、再生骨料类型、骨料含水状态、制备及养护工艺等方面)对再生混凝土的抗压性能进行分析,总结了各因素对抗压强度的影响规律。再生骨料品质的劣性导致现阶段再生混凝土大多应用在非结构构件上,不能充分发挥其经济效益,此外,我国还没有一套完整的再生骨料的应用体系,从破碎工艺到骨料强化工艺等都缺乏指导性的建议或规范。本文建议不宜采用取代率高的再生骨料制备混凝土,尽量选用强度较高的废弃混凝土制成的再生骨料,并在成本控制范围内对骨料进行强化。考虑骨料吸水导致的水灰比变化,通过人工改良级配外加科学的养护方式,可以使再生混凝土达到普通混凝土的抗压性能。最后还归纳了骨料强化方法和再生混凝土抗压强度预测公式,为再生混凝土的工程实际应用奠定了理论基础。
In recent years,the rapid development of the city has led to the generation and discharge of a large amount of construction waste.Making recycled aggregate from the construction waste and using it can effectively alleviate the environmental problems caused by the construction waste landfill.In line with China’s low-carbon environmental protection,sustainable development of the basic national policy.The old mortar attached to the surface of recycled aggregate has the characteristics of high porosity and high water absorption,which not only greatly reduces the compactness of recycled concrete,but also affects the hydration process of cement and adversely affects the mechanical properties of recycled concrete.Recycled concrete has a more complex interface transition zone than ordinary concrete due to the existence of old mortar.The author summarizes some scholars’microscopic research on interface transition zone of recycled concrete and reveals the influence of interface transition zone of new and old aggregate mortar on compressive properties of recycled concrete.At the same time,the compressive properties of recycled concrete are analyzed from macro factors such as replacement rate of recycled aggregate,source of recycled aggregate,type of recycled aggregate,water-bearing state of aggregate,preparation and curing process,and the influence law of each factor on compressive strength is summarized.The inferior quality of recycled aggregate leads to the fact that recycled concrete is mostly used in non-structural components at the present stage,which cannot give full play to its economic benefits.In addition,there is no complete system for the application of recycled aggregate in China,and there are no guiding suggestions or specifications from crushing process to aggregate strengthening process.This paper suggested that the preparation of recycled concrete is unfavorable use high replacement ratio,choose high strength waste concrete made of recycled aggregates,within the scope of the cost control to strengthen ag
作者
王俊辉
黄悦
杨国涛
魏琦安
刘文卓
WANG Junhui;HUANG Yue;YANG Guotao;WEI Qian;LIU Wenzhuo(School of Civil Engineering,Qingdao University of Technology,Qingdao 266033,Shandong,China;Zhongqing Jianan Construction Group Co.,Ltd.,Qingdao 266033,Shandong,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2022年第S01期278-286,共9页
Materials Reports
基金
国家自然科学基金(51608135,51978351)
山东省工业和信息化厅企业技术创新项目(202060101618,202060103805)
山东省泰山学者项目(tsqn201909127)
关键词
再生混凝土
破坏机理
强度影响因素
骨料强化
抗压强度预测
recycled aggregate concrete
failure mechanism
strength influencing factors
aggregate strengthening
compressive strength prediction
