水下不分散混凝土试验与抗裂性能分析

针对目前混凝土在水下浇筑过程中出现的分散严重、无法达到预定强度、浇筑完成后电通量高的问题，对影响混凝土抗分散性、强度的因素进行了试验研究及理论分析．首先采用了调整外加剂、增加掺和料的方式，对使用2种类型的外加剂制作的6组配合比的混凝土试件进行了试验研究，找出了影响混凝土电通量与氯离子渗透性的关键影响因素，并对混凝土内含裂纹初始起裂角随裂纹倾角的变化规律进行了研究，找出了影响混凝土抗裂强度的因素，并将混凝土水下悬浊物含量降低至预定范围之内；通过对陆上和水下工程的验证性应用成功研制了水下不分散混凝土，并对其性能作进一步深化研究．所推荐的不分散混凝土配合比，已经成功得到工程应用的验证，可借鉴和推广应用到类似的水下浇筑、修复等工程的施工中．

Analysis of Performance and Crack Resistance of Non-Dispersible Concrete Underwater Conditions

In view of the problem that the concrete disperses seriously in the process of underwater pouring, and therefore cannot achieve the predetermined strength, with high electric flux after the pouring. The anti-dispersity of concrete is investigated. The factors that affect the anti-dispersion and mechanical strength were analyzed． Experiments on 6 groups of concrete specimens with different mixing ratios with 2 kinds of admixtures are carried out. The key factors affecting the electrical flux and chloride permeability of concrete are found out. The variation law of crack initiation angle with crack tip is studied. The content of concrete suspended underwater is reduced to a pre-specified range. The underwater non-dispersible concrete is successfully developed through the verification of engineering applications on land and underwater. The performance has been further studied. The verified non dispersive concrete mixture ratio has been successfully applied to the engineering projects. This work can provide reference and be applied to similar underwater casting and repairing.