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- 混凝土与制品
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低温升高抗裂机制砂隧道衬砌混凝土的研究与应用
作者：陈露一1，2，包嘉诚1，2
（1.桥梁结构健康与安全国家重点实验室，湖北 武汉 430034；2.中铁大桥科学研究院有限公司，湖北 武汉 430034）
摘要：隧道衬砌混凝土易在温度应力和体积收缩下产生开裂，进而影响工程结构外观质量和耐久性。项目依托保神高速茅山隧道工程，系统研究了不同胶凝材料体系对机制砂衬砌混凝土水化放热特性的影响，及膨胀剂用量对衬砌混凝土早期抗裂性能及耐久性能的影响。结果表明，双掺粉煤灰及石灰石粉可显著降低混凝土的水化温升，但对其力学性能产生不利影响，掺加氧化钙膨胀剂后，混凝土致密度提高，具有优异的抗侵蚀性和抗碳化性能。研究成果直接应用于茅山隧道衬砌混凝土工程的施工，效果良好。
关键词：衬砌混凝土；机制砂；抗裂；耐久性
中图分类号：TU528.041 文献标识码：A 文章编号：1001-702X（2021）01-0019-05
Research and application of sand tunnel lining concrete with anti-cracking mechanism at low temperature
CHEN Luyi1，2，BAO Jiacheng1，2
（1.State Key Laboratory of Bridge Structure Health and Safety，Wuhan 430034，China；
2.China Railway Bridge Science Research Institute，Wuhan 430034，China）
Abstract：Tunnel lining concrete is prone to cracking under temperature stress and volume shrinkage，which affects the appearance quality and durability of the engineering structure. Relying on the Baoshen Expressway Maoshan Tunnel Project，the project systematically studied the effects of different cementitious material systems on the hydration and heat release characteristics of machined sand lining concrete，and the influence of the amount of expansion agent on the early crack resistance and durability of lining concrete. Research shows that double-mixed fly ash and limestone powder can significantly reduce the hydration temperature rise of concrete，but adversely affect its mechanical properties. After adding calcium oxide expansion agent，the density of concrete is increased，and it has excellent erosion resistance and carbonization resistance performance. The research results are directly applied to the construction of Maoshan Tunnel Lining Concrete Project with good results.
Key words：lining concrete，machined sand，crack resistance，durability