| 摘要: |
| 通过平板开裂试验，研究陶粒内养护对不同强度混凝土早期抗裂性能的影响规律，并结合混凝土塑性收缩试验、绝热温升试验和内部相对湿度变化，探明陶粒内养护提高混凝土早期抗裂性能的微观机理.结果表明：在混凝土中使用饱水陶粒替代部分粗骨料，能够减少混凝土材料的早期塑性收缩，降低大体积混凝土内部的水化温升，有效提高混凝土早期的抗裂性能，达到显著的内养护效果；饱水陶粒通过减缓早龄期试件内部相对湿度的快速下降，改善了胶凝材料水化环境，有效抑制了胶凝材料水化过程引发的自干燥作用，降低了混凝土材料早期收缩，从而提高了混凝土材料的抗裂性能；C30与C60两个强度混凝土中饱水陶粒替代粗骨料的最佳比例均为20%（体积分数）. |
| 关键词: 内养护 陶粒 抗裂性能 塑性收缩 内部相对湿度 |
| DOI：103969/j.issn1007 9629201505005 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51408037，51578049）；交通运输部重大科技专项基金资助项目（2011318494160） |
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| Crack Resistance of Ceramsite Self Curing High Performance Concrete |
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HAN Song1, AN Mingzhe1, GUO Rui2, LIU Gao2
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1.School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China;2.Highway Bridge NationalEngineering Research Centre, CCCC Highway Consultants Co., Ltd., Beijing 100088, China
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| Abstract: |
| Crack resistance of self curing concrete was investigated through plate cracking test in early age. The plastic shrinkage, adiabatic temperature rise and internal relative humidity change of self curing concrete were homologously analyzed. The crack resistance change of self curing concrete and its micro mechanisms were clarified. The results show that the early plastic shrinkage is reduced and the adiabatic temperature rise is lowered by waterlogged ceramsite, which effectively enhances the crack resistance of self curing concrete. The hydration environment of cementitious material in concrete is improved by waterlogged ceramsite and its self curing effect. The optimal proportion of waterlogged ceramsite replacing coarse aggregate was proposed as 20%(by volume) in both C30 and C60 concrete. |
| Key words: self curing ceramsite crack resistance plastic shrinkage internal relative humidity |
