摘要
建筑固废在破碎为再生骨料过程中产生的砂粉具有填充和火山灰效应,为实现建筑固废绿色再生利用提供新途径。本文以废砖、废混凝土为原材料制备混合型再生砂粉(再生复合微粉、再生细骨料)和再生粗骨料。采用正交试验方法结合室内击实试验、冻融试验、干缩试验探究混合型再生砂粉对水泥稳定碎石耐久性能的影响,确定混合型再生砂粉的最佳组成,运用SEM结合能谱分析揭示混合型再生砂粉对水泥稳定碎石耐久性能影响的机理。结果表明,经冻融循环后试件的抗压强度损失值均小于基准试件,最大降幅为11.63%,干缩应变最大增幅为69.75%。混合型再生粗骨料对水泥稳定碎石最佳含水量、抗冻性能影响最为显著;混合型再生细骨料降低试样抵抗变形的能力,对其干缩性能影响高度显著。混合型再生砂粉可以有效改善混合料的密实度,火山灰效应使试件Ca/Si比降低52.83%。极差分析可确定混合型再生复合微粉、再生细骨料、再生粗骨料最佳替代量依次为40%、20%、40%(质量分数)。研究成果可为再生材料在道路工程水泥稳定碎石基层应用提供参考。
Construction solid waste can now be recycled and used in a more environmentally friendly manner by utilizing the sand powder created during the process of crushing it into recycled aggregate.This recycled sand powder has beneficial filling and volcanic ash effects.In this study,mixed recycled sand powder(recycled composite micronized powder,recycled fine aggregate),and recycled coarse aggregate were produced using discarded bricks and concrete as raw materials.The study examined the effect of mixed recycled sand powder on the durability of cement-stabilized aggregates.The ideal composition of mixed recycled sand powder was determined using the orthogonal test method,along with indoor compaction tests,freeze-thaw tests,and dry shrinkage tests.The influence mechanism of mixed recycled sand powder on the durability of cement-stabilized aggregates was revealed using scanning electron microscope(SEM)in conjunction with energy spectrum analysis.The results show that the compressive strength loss of specimens after freeze-thaw cycle is smaller than that of benchmark specimen,with a maximum decrease of 11.63%,and the maximum increase of dry shrinkage strain is 69.75%.Mixed recycled coarse aggregate has the most significant impact on the optimal moisture content and frost resistance of cement-stabilized aggregates.Mixed recycled fine aggregate reduces the deformation resistance of specimen and has a significant effect on its dry shrinkage.Mixed recycled sand powder can effectively improve the density of mixture.The volcanic ash effect reduces the Ca/Si ratio of specimens by 52.83%.Variance analysis identifies that the ideal replacement amount of mixed recycled composite micronized powder,recycled fine aggregate,and recycled coarse aggregate is 40%,20%,and 40%(mass fraction),respectively.These research findings can serve as a guide for recycled materials in the base layer of cement-stabilized aggregates used in road construction.
作者
谢祥兵
司马笑情
张艺林
王凯威
蒋冰洋
刘晨晨
李广慧
XIE Xiangbing;SIMA Xiaoqing;ZHANG Yiin;WANG Kaiwei;JIANG Bingyang;LIU Chenchen;LI Guanghui(School of Civil Engineering and Architecture,Zhengzhou University of Aeronautics,Zhengzhou 450046,China;School of Materials,Zhengzhou University of Aeronautics,Zhengzhou 450046,China;Henan Vocational College of Water Conservancy and Environment,Zhengzhou 450008,China)
出处
《硅酸盐通报》
CAS
北大核心
2023年第11期4051-4062,共12页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金(51378474)
中原科技创新领军人才中原千人计划(194200510015)
河南省科技攻关项目(192102310012)
郑州航空工业管理学院青年科研基金支持计划专项资助(23HQN01007)
郑州航空工业管理学院研究生教育创新计划基金(2023CX69)。
关键词
再生砂粉
水泥稳定碎石
正交试验
干缩性能
抗冻性能
击实试验
recycled sand powder
cement-stabilized aggregate
orthogonal test
dry shrinkage
frost resistance
compaction test