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由于桥涵建设的发展,对混凝土材料提出了新的要求,同时近年来国内减水剂的研制与生产也有较大进展,这就为在桥涵施工中推广应用混凝土减水剂提供了必要性与可能性。目前减水剂已在多方面应用,下面试举几例说明:1.掺用减水剂可以获得早强与高强混凝土。如广东东莞县万江大桥,是一座予应力薄壁箱形连续梁桥,采用顶推法施工,箱梁混凝土设计标号 R_(28)≥400~#,并要求 R_3≥300~#以进行张拉。根据以往经验,必须使用600~#水泥,较小的水灰比,这样就给施工造成困难,有时还影响工程质量。经过试验,决定掺加减水剂 N.N.O,
Due to the development of bridge and culvert construction, new requirements are put forward for concrete materials. In the meantime, great progress has been made in the research and production of domestic water reducer, which has provided the necessity and possibility for the popularization and application of concrete water reducer in bridge and culvert construction Sex. At present, water reducer has been applied in many aspects, the following to cite a few examples: 1. Addition of superplasticizer can get early strength and high strength concrete. Such as Dongguan, Guangdong Wanjiang Bridge, is a prestressed thin-walled box-girder continuous girder, the use of push construction, box girder concrete design code R_ (28) ≥ 400 ~ #, and require R_3 ≥ 300 ~ # for Zhang Pull. According to past experience, you must use 600 ~ # cement, a smaller water-cement ratio, thus giving rise to difficulties in construction, and sometimes affect the quality of the project. After testing, decided to add water reducer N.N.O,