掺合料裹骨料工艺对再生骨料混凝土性能的影响.pdfVIP

2007年第 12期(总第 218期 ) 混 凝 土 理 论 研 究 Number12in 2007(Tota1No 218) Concrete THE0RETICAL RESEARCH 掺合料裹骨料工艺对再生骨料混凝土性能的影响 雷 霆，孔德玉，郑建军 (浙江工业大学 建筑工程学院，浙江杭州 310014) 摘 要： 采用一种掺合料裹骨料搅拌工艺，在水泥裹骨料工艺基础上，进一步改善再生骨料一水泥石界面过渡区，提高再生混凝土性能， 研究了搅拌工艺、新拌混凝土坍落度、掺合料品种对再生混凝土强度和抗氯离子渗透性的影响。结果表明，采用掺合料裹骨料工艺，可在水 泥裹骨料工艺基础上进一步大幅度提高早龄期强度和抗氯离子渗透性能，对后期强度和抗氯离子渗透性也有提高，但幅度较小；提高新拌 混凝土坍落度有助于提高强度，但对抗氯离子渗透性能略有影响，采用掺合料裹骨料工艺可减小坍落度对再生混凝土性能的影响；采用矿 渣掺合料更有助于提高再生混凝土强度和抗氯离子渗透性能。 关键词： 再生混凝土；掺合料裹骨料；抗氯离子渗透性；界面过渡区 中图分类号：TU528．041 文献标志码： A 文章编号： 1002—3550(2007)12—0038—04 Effect of su~ace coating of aggregate by admixture on properties of recycled aggregate concrete LEITing，KONGDe-yu，ZI-IENGJian-jun (College ofCivil EngineeringArchitecture，Zh~iang University ofTechnology，Hangzhou 310014，China) Abstract： A novel mixing method was applied tO realize surface coating of aggregate by admixture for further improving microstructure of in- terfacial transition zone(ITZ)and properties ofrecycled aggregate concrete(RAC)．Effects ofmixing m~hods，slump ofthe flesh concr~e and coating by various admixtures on compressive strength and chloride ions penetration resistance of RAC were investigated．The results show that compressive strength and chloride ions penetration resistance of the concrete Can be further enhanced through surface coating of admixture around the aggregates during mixing，as compared tO that by the surface-coating-by-cement mixing method，especially at early ages．Increasing slump of the flesh concrete helps enhance compressive strength but weakly harm the chloride ions penetration resistance ofthe hardened RAC for both mix- ing methods．However，the negative effects of increasing slump on properties of