This test method covers a procedure for determining the relative resistance of concrete(including concrete overlays and impergnated concrete) to abrasion under water. This procedure simulates the abrasive action of waterborne particles (silt,sand,gravel, and other solids). This test method is intended to qualitatively simulate the behavior of swirling water containing suspended and transported solid objects that produce abrasion of concrete and cause potholes and related effects such as the flow of water containing debris over spillways during monsoons. This test method should provide a relative evaluation of the resistance of concrete to such action. The results are expected to be useful in selection of materials, mixtures, and construction practices for use where such action is to be expected. The test method is not intended to provide a quantitative measurement of the length of service that may be expected from a specific concrete. Steel balls tumbling in a circular orbit in swirling water on th