基于废渣粉末的再生水泥基材料性能试验研究
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作者:白卫峰 亢勇 吕亚军 杨龙宾 郭晓宁 朱晨辉
摘 要:为探讨混凝土搅拌站废渣的再生利用问题,对搅拌站清洗废渣进行处理,得到粒径为75 μm以下的废渣粉末(WSP),将WSP按照不同比例对胶凝材料中的水泥进行部分替换,制备成WSP混凝土。测试了其坍落度、抗压强度及孔隙结构,进行了热重、生态和经济性分析,并根据性价比给出了替换率的建议值。结果表明:1)采用WSP替换水泥不会增加混凝土孔隙结构中有害孔和多害孔的比例;2)WSP替换率为3%~20%时,所制备的混凝土具有较好的流动性,7,28 d抗压强度的平均值分别为45,54 MPa;替换率超过12%时,抗压强度呈现出一定的减小趋势;3)当替换率为8%,12%,16%,20%时,WSP混凝土的成本及生态指标数据均较普通混凝土有所下降;建议WSP最佳替换率为12%左右。研究结果为搅拌站清洗废渣的再生处理和资源化利用提供了试验依据。
关键词:非金属建筑材料;废渣粉末;水泥基材料;资源化利用;D-最优设计
中图分类号:TU528;X705 文献标识码:A
DOI: 10.7535/hbgykj.2022yx03010
Experimental study on properties of recycled cement-based materials based on waste slag powder
BAI Weifeng1,KANG Yong1,LYU Yajun2,YANG Longbin2,GUO Xiaoning2,ZHU Chenhui2
(1.College of Water Conservancy,North China University of Water Resources and Electric Power,Zhengzhou,Henan 450046,China;2.College of Architecture,North China University of Water Resources and Electric Power,Zhengzhou,Henan 450046,China)
Abstract:In order to explore the recycling of waste slag in concrete mixing plant,the cleaning waste slag of mixing plant was treated to obtain waste slag powder (WSP) with particle size less than 75 μm.WSP is partially replaced with cement in cementitious materials according to different proportions to prepare WSP concrete.The slump,compressive strength and pore structure were tested,the thermogravimetric,ecological and economic analysis were carried out,and the recommended value of replacement rate was given according to the cost performance.The results show that:1) replacing cement with WSP will not increase the proportion of harmful holes and multi harmful holes in concrete pore structure.2) When the replacement rate of WSP is 3%~20%,the prepared concrete has good fluidity;The average values of 7 d and 28 d compressive strength are 45 MPa and 54 MPa respectively;When the replacement rate exceeds 12%,the compressive strength shows a certain decreasing trend.3) When the replacement rate is 8%,12%,16% and 20%,the cost and ecological index data of WSP concrete are lower than that of ordinary concrete.It is suggested that the best replacement rate of WSP is about 12%.The research results provide an experimental basis for the regeneration treatment and resource utilization of cleaning waste slag in mixing plant.
Keywords:
non-metallic building materials;waste slag powder;cement-based materials;resource utilization;D-optimal design
随着中国城市化进程的加速和建筑业的蓬勃发展[1-2],建筑垃圾空前增加,搅拌站和混凝土罐车在清洗过程中同样会产生大量建筑废渣。混凝土运输车在完成输送任务后,为了避免残留混凝土硬化结块,造成清洁困难[3],用清水冲洗运输车罐体,形成了一定的沉淀物,即为清洗废渣(以下简称废渣)。据不完全统计,每生产1 m3混凝土平均产生废渣0.02 t,以年产16亿m3混凝土计算,每年至少产生废渣3 200万t[4]。建筑垃圾巨大的废渣量给外运造成不小的负担,并且它的乱堆乱放不仅侵占土地资源,污染土壤、水体、大气,也给固体废弃物处理增加了压力。目前,中国资源利用率偏低[5],若能够对清洗废渣进行有效的资源化再生利用[6],将对中国建筑业发展和生态环境保护起到重要的推幼饔谩
nlc202206201604
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