泄水建筑物过水表面混凝土所遇到的一个特殊问题就是水流对过水边界混凝土的剥蚀,即泥沙磨损和空蚀.对质量密实的混凝土,可以承受流速达40米/秒的清水冲刷,不致引起表面混凝土损坏.对挟带砂砾石的水流,由于砂砾石运动磨擦和跳跃冲击,流速不要太大,就能够对过水表面的混凝土造成严重的损坏. A special problem encountered when water draining a concrete over a water surface is the denudation of the water flow to the concrete at the boundary of the passing water, ie, sand abrasion and cavitation erosion. For dense concrete, it can withstand water scouring at a flow rate of 40 m / s , Will not cause damage to the surface of the concrete.For sand and gravel-bearing water flow, due to sand and gravel movement friction and jumping impact, the flow rate should not be too large, it can cause serious damage to the concrete on the surface of the water.