| 摘要: |
| 针对再生骨料单一材料涂敷下,界面过渡区(ITZ)改善效果欠佳导致的混凝土性能提升不足及机理不明的问题,以丙乳、粉煤灰、石膏、P.O 42.5水泥为复合净浆复配材料,探究了不同配比净浆涂覆下再生骨料性能,同时分析了利用再生骨料配制的再生混凝土的力学性能、抗渗性能、干缩变形,并结合X射线衍射分析、扫描电子显微镜-能谱法、孔结构分析对不同组分下再生骨料界面过渡区的改善机制进行了机理分析。结果表明：涂覆净浆法可有效降低再生粗骨料压碎值与吸水率,相较于传统纯水泥浆涂敷法,掺入丙乳、石膏、分煤灰的复合净浆的降低效果更为显著；再生骨料表面涂覆不同配比的净浆材料,可以显著提升再生混凝土的性能,同时随着再生骨料强度等级提升,性能提升效果减弱；聚合物复合净浆提升再生骨料的性能在于各个组分的嵌合及作用效果叠加,最终实现再生骨料与再生混凝土的性能显著提升。 |
| 关键词: 再生骨料 复合净浆 涂覆改性 再生混凝土 界面过渡区 |
| DOI： |
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| 基金项目:国家重点研发计划资助项目 (2022YFC3005503)；安徽省自然科学基金(2208085US11)。 |
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| Effect of composite cement paste on the performance of recycled concrete aggregate and mechanism analysis |
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WEI Hua1, LI Qing-an2, CHEN Lian-jun3, LU Hao1, HE Yang1
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1.The National Key Laboratory of Water Disaster Prevention Nanjing Hydraulic Research Institute;2.Shandong Yellow River Reconnaissance Design Reseach Institute Company Limited;3.Hanjiang Gushan Hydropower Development Coltd
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| Abstract: |
| To address the problem of insufficient concrete performance enhancement and unknown mechanism due to poor improvement of interfacial transition zone (ITZ) under single material coating of recycled aggregates, which leads to slight improvement of concrete performance, this paper explores the series of performance exploration of recycled concrete under different ratios of cement paste coating by using acrylate copolymer emulsion, fly ash, gypsum, and P-O 42.5 cement as the polymer composite cement paste compound materials, and combines the X-ray diffraction analysis, scanning electron microscope-energy dispersive X-ray spectroscopy, and pore structure analysis to investigate and analyze the improvement mechanism of the interface transition zone (ITZ) of recycled concrete under different components. The improvement mechanism of the interfacial transition zone of recycled concrete under different components was investigated and analyzed. The test results show that the polymer composite slurry coating method can effectively reduce the crushing value and water absorption rate of recycled aggregates, and compared with the traditional pure cement slurry coating method, the composite slurry mixed with acrylate copolymer emulsion, gypsum, and fly ash has a more significant reduction effect; the coating of recycled aggregates surface with different ratios of slurry materials can significantly improve the performance of recycled concrete, and at the same time, with the increase of the strength grade of recycled aggregates, the effect of the improvement of the performance is weakened; polymer composite slurry to enhance the performance of recycled aggregates lies in the chimerical and superimposed effect of each component, ultimately realizing a significant improvement in the performance of recycled aggregates and recycled concrete. |
| Key words: recycled aggregate composite cement paste coating modification recycled concrete interfacial transition zone |
