再生骨料取代率及粒径对机制砂混凝土性能影响试验研究  

Experimental study on the effect of recycled aggregate substitution rate and particle size on the performance of mechanized sand concrete

作　　者：王伦 周荣清 刘林 冷传奇 郭威 WANG Lun;ZHOU Rongqing;LIU Lin;LENG Chuanqi;GUO Wei(CCCC Third Highway Engineering Bureau Co.,Ltd.,Fourth Engineering Branch.,Chongqing 401147,China)

机构地区：[1]中交第三公路工程局有限公司第四工程分公司,重庆401147

出　　处：《混凝土》2025年第3期168-171,共4页Concrete

摘　　要：为了促进固体建筑垃圾二次循环利用,缓解环境污染问题,实现再生粗骨料在混凝土中应用,本文开展了再生粗骨料取代率及粒径对C40机制砂混凝土性能影响研究.借助混凝土仪器设备,通过再生粗骨料取代率(R)试验、再生粗骨料粒径(D)试验研究对混凝土流动性能、力学性能的影响.结果表明:(1)随着再生粗骨料取代率提高,混凝土初始坍落度逐渐减小、30 min坍落度、初始扩展度、30 min扩展度均逐渐减小;7 d轴心抗压强度、28 d轴心抗压强度、劈裂抗拉强度逐渐降低.通过再生粗骨料取代率对混凝土流动性能、力学性能的影响规律得出固定粒径5~10 mm、10~20 mm、20~31.5 mm质量比1∶1∶1复配再生粗骨料,混凝土中取代率不易超过45%,即414 kg/m^(3).(2)再生粗骨料粒径变化对混凝土流动性能、力学性能均有较大影响.再生粗骨料中提高粒径D1=5~10 mm掺量能够使其颗粒级配更加近似于天然粗骨料,更好发挥“骨架支撑效应”,使混凝土性能降低幅度更小;通过试验结果得出再生粗骨料粒径最佳比例为m(D_(1)=5~10 mm)∶m(D_(2)=10~20 mm)∶m(D_(3)=20~31.5 mm)=2∶1∶1.(3)相比普通混凝土,再生粗骨料混凝土综合性能满足C40混凝土应用要求;再生粗骨料应用是实现固体建筑垃圾二次利用的重要途径。In order to promote the secondary recycling of solid construction waste,alleviate environmental pollution problems,and achieve the application of recycled coarse aggregate in concrete,it conducted a study on the influence of the replacement rate and particle size of recycled coarse aggregate on the performance of C40 mechanism sand concrete.Using concrete equipment,the influence of recycled coarse aggregate replacement rate(R)test and recycled coarse aggregate particle size(D)test on the flow and mechanical properties of concrete was studied.The results show that(1)As the replacement rate of recycled coarse aggregate increases,the initial slump of concrete gradually decreases,and the slump at 30 minutes,initial expansion,and expansion at 30 minutes all gradually decrease.The axial compressive strength at 7 d,axial compressive strength at 28 d,and splitting tensile strength gradually decrease.By studying the influence of the replacement rate of recycled coarse aggregate on the flow and mechanical properties of concrete,it is found that when fixed particle sizes of from 5 mm to 10 mm,from 10 mm to 20 mm,and from 20 mm to 31.5 mm are mixed with recycled coarse aggregate in a mass ratio of 1:1:1,the replacement rate in concrete is not likely to exceed 45%,which is 414 kg/m.(2)The change in particle size of recycled coarse aggregate has a significant impact on the flow and mechanical properties of concrete.Increasing the particle size D,is from 5 mm to 10 mm in recycled coarse aggregate can make its particle size distribution more similar to natural coarse aggregate,better exert the"skeleton support effect",and reduce the decrease in concrete performance to a smaller extent.According to the experimental results,the optimal ratio of recycled coarse aggregate particle size is m(D_(1)is from 5 mm to 10 mm):m(D_(2)is from 10 mm to 20 mm):m(D_(3)is from 20 mm to 31.5 mm)-2:1:1.(3)Compared with ordinary concrete,the comprehensive performance of recycled coarse aggregate concrete meets the application requirements of C40 con

关 键 词：再生粗骨料 取代率 粒径 流动性能 力学性能 

分 类 号：TU528.01[建筑科学—建筑技术科学]