自七十年代起,我国开始推广应用掺外加剂冬期混凝土施工技术,并已取得了巨大成果。但由于我国地域辽阔,许多新技术的推广还需要一个过程,一些地方在施工中,对如何保证质量,应采取什么措施还不十分明确,对于为什么必须这样做更认识不够,影响了冬期施工技术的推广。有些地方想用而不敢用;有的地方则因为必要的措施采取不够,未能达到预期效果,严重者甚至造成质量事故。例如我国一座冬期施工的铁路桥梁,开春后测定其桥墩台混凝土试件强度,仅及设计强度的三分之一,最后不得不炸掉重建;东北某工程,由于使用了某种负温外加剂,造成了钢筋严重锈蚀,使混凝土产生大量裂缝,严重影响了质量,被迫停工。 Since the 1970s, China began to promote the use of admixture winter concrete construction technology, and has made great achievements. However, due to the vast territory of China, the promotion of many new technologies requires a process. In some places where construction is being carried out, it is not clear exactly what measures should be taken to ensure quality, and it is not clear enough why this must be done, and it affects the winter construction technology. Promotion. Some places do not want to use them; some places do not take enough measures because of necessary measures and fail to achieve the desired results. In serious cases, they even cause quality accidents. For example, in China, a railway bridge constructed during the winter period, after its spring, the strength of concrete specimens of the bridge piers was measured, only one-third of the design strength, and they had to be destroyed and rebuilt. In the case of a project in the northeast, some kind of negative temperature additive was used. Caused a serious corrosion of the steel bars, causing a large number of concrete cracks, seriously affecting the quality, forced to stop work.