极旱荒漠地区无砟轨道道床板防裂措施

Measures of crack-prevention of ballastless track bed plate in extremely arid and desert region

针对CRTSⅠ型双块式无砟轨道道床板现浇混凝土容易开裂的现状,结合新建兰新铁路极旱荒漠地区无砟轨道道床板的施工,总结出4种常见的道床板混凝土裂缝形式。分析了产生裂缝的主要原因,通过线外试验段选取了适宜于新建兰新铁路极旱荒漠地区无砟轨道道床板施工的最优混凝土配合比。在养护棚中制作道床板,浇筑混凝土时进行二次振捣并多次抹面,采取内掺养护材料、外喷养护剂的"内部抗裂、外部防裂"以及覆盖土工布等防裂措施,从而有效避免了道床板混凝土开裂,提高了无砟轨道道床板施工质量。

According to the current cast-in-place concrete track bed plate crack situation of C RT SⅠ type double block ballastless track,this paper concluded the four kinds of common concrete track bed plate cracks form combing with the ballastless track bed plate construction of new Lanzhou-Xinjiang railway in the extreme arid desert region. T his paper also analyzed the main causes of cracks,determined the optimal concrete mixing ratio of ballast track bed plate construction in the extreme arid desert region through the section test beyond the line. M aking the track bed plate in the maintenance shed,doing two time vibration and repeatedly plaster for pouring concrete,adopting crack control measures such as mixing maintenance material inside and spraying curing agent outside named“internal and external anti-crack”,and covering geotextile etc.,could avoid the concrete track bed plate crack and improve the construction quality of the ballastless track bed plate.