铁路混凝土耐久性理论与提升方法

Durability Theory and Improvement Method of Concrete in Railway Engineering

面对铁路工程发展的新特点和新需求,迫切需要开展混凝土理论与耐久性提升方法的研究以保证铁路混凝土的长服役寿命。文章介绍了铁路混凝土的发展历程与混凝土耐久性新需求,阐述了铁路混凝土裂缝的表现形式与危害、开裂机理、收缩模型和混凝土抗裂主要措施,总结了铁路建设所面临的混凝土冻融与硫酸盐腐蚀破坏机制及耐久性提升方法。最后指出铁路混凝土结构耐久性评估应考虑疲劳和环境耦合影响,同时应加强现浇铁路结构混凝土开裂机理的探索。

Facing the new characteristics and demands of railway engineering development,it is urgent to carry out research on concrete theory and durability improvement methods to ensure the long service life of concrete in railway engineering.The development history of concrete in railway engineering and the new requirement of concrete durability were introduced in this paper.The manifestation and hazard of concrete cracks in irailway engineering,cracking mechanism,shrinkage model and main measures of concrete crack resistance were expounded.The mechanism of concrete freeze-thaw and sulfate corrosion damage and the methods of durability improvement faced by railway construction were summarized.Finally,it was pointed out that fatigue and environmental coupling should be considered in the durability evaluation of concrete structures in railway engineering,and the cracking mechanism of cast-in-place concrete structures in railway engineering should be explored.