高寒地区混凝土箱梁施工关键技术研究

Key Construction Technologies of Concrete Box Girder in Alpine Region

在高海拔寒冷地区恶劣的自然环境,为了提高混凝土箱梁的强度和抗冻耐久性,需要对混凝土箱梁施工关键技术进行研究。首先,分别掺加减水剂和引气剂,通过试验研究了不同外加剂对高寒区混凝土各项性能的影响,并确定了高海拔寒冷地区混凝土箱梁的最优配合比。然后,根据规范并结合工程所处高海拔地区情况,提出了混凝土原材料入仓温度、箱梁浇筑过程保温及温度控制、预制箱梁制作和蒸养措施等施工关键技术。最后,通过回弹法现场测试箱梁强度,验证了优化方案的有效性。本文的研究成果可为类似工程提供参考和指导。

In the harsh natural environment of high altitude and cold regions, in order to improve the strength and frost resistance durability of concrete box girder, it is necessary to propose key technologies of concrete box girder construction. Firstly, water reducing agent and air entraining agent are added respectively. The effects of different admixtures on the properties of alpine-cold concrete are analyzed through experiments, and the optimal mix proportion of concrete box girder in high altitude and cold area is determined. Then, according to the specifications and combined with the situation of the high-altitude area where the project is located, the construction key technologies such as the temperature of concrete raw materials entering the warehouse, the heat preservation and temperature control of the box girder pouring process, the fabrication of prefabricated box girder and steam curing measures are proposed. Finally, the box girder strength was tested on site by the rebound method, and the effectiveness of the optimization scheme was verified. The research results of this paper can provide reference and guidance for similar projects.