坑式蒸汽养护是当前中小型构件生产企业常用的生产方式,具有投资省、上马快和使用方便等优点。但是也存在一些质量问题,诸如以下几个方面。一、构件酥松或表面起皮其起因是构件成型后停放时间较短或升温过快,致使内部结构破坏或表面因蒸汽冷凝水的冲滴而起皮。构件成型后的停放,其目的是使构件在蒸养前具有足够的初期强度,以抵御其蒸养时的变形、温差应力等所产生的结构破坏。停放时间的长短与构件混凝土的干硬度和蒸养时的升温速度有关。每种配比不同的混凝 Pit-type steam curing is a common production method used by small and medium-sized component manufacturers. It has the advantages of investment, speed and ease of use. But there are also some quality issues, such as the following aspects. First, the component is loose or the surface of the skin from the cause is the short time after the formation of the component molding or heating up too fast, resulting in internal structural damage or the surface of the condensing water from the steam dripping from the skin. After the components are molded, their purpose is to make the components have enough initial strength before steam curing to resist the structural damage caused by the deformation during steam curing and temperature stress. The length of parking time is related to the dry hardness of the concrete and the heating rate during steaming. Different coagulation ratios