节段拼装梁湿接缝混凝土冬季施工温度控制技术

Temperature Control Techniques in Winter Seasons for the Wet Joint Concrete of Assembled Sections

常温环境下进行节段拼装混凝土梁的施工现在已经有一套成熟的施工技术,但目前还没有在寒冷地区进行冬季施工的先例。特别是冬季进行湿接缝混凝土的浇筑,混凝土温度控制是质量控制的重中之重。由于是在高空进行作业,而且湿接缝是分散布置在整孔混凝土箱梁范围内,热量散发快,混凝土温度控制有一定的难度。在包西铁路通道黑龙沟大桥48 m节段拼装混凝土箱梁施工中,从混凝土拌和到浇筑、养护、拆模期间,采用原材料加热、混凝土运输和浇筑过程保温、特制的保温篷布包裹、蒸汽养护等温度控制措施,有效地保证了湿接缝混凝土的质量,圆满完成了施工任务。所采取的方法具有成本低、效率高、温度调节操作简单的特点,为冬季施工节段拼装梁积累了经验。

In the process of assembling the 48m sections of concrete box girders of Heilonggou bridge on Baotou-Xi＇an railway, in the period from concrete mixing to casting, seasoning and stripping, measures such as heating the materials, heat insulation during transportation and casting of concrete, temperature control measures including envelop by custom-made heat insulating canopy and steaming maintenace etc. wc,e adopted, which effectively ensured the quality of concrete in the wet joints and the successful completion of the project. The measures adopted are of low cost, high efficiency and easy to manipulate the temperatures, with experience accumulated for the assembling sectioned girders in winter seasons.