Experimental Study on Hydro-Abrasion Performance of Polyvinyl Alcohol Fiber Cementitious Composites

Bridge safety during service is greatly influenced by hydro-abrasion caused by waterborne sand. An independently developed testing device was employed to conduct hydro-abrasion tests on a type of anti-abrasion material, i.e., polyvinyl alcohol (PVA) fiber reinforced cement based composites. Ordinary mortar was selected as the reference material. Firstly, the compressive strengths of the two types of materials were tested and then the weight losses caused by hydro-abrasion were measured. The hydro-abrasion characteristics of the two materials under different impacting angles were analyzed. Finally, the computational fluid dynamics program was used to conduct numerical simulation and the generation mechanisms of abrasion pits were explored on the basis of flow field analysis. Results show that water-binder ratio has the most influence on the anti-abrasion performance; the smaller the water-binder ratio, the larger the material compressive strength and the better the anti-abrasion performance. Abrasion pits on the specimen surfaces have different shapes when suffering impacting of different angles, i.e., the abrasion pit is circular when the impacting angle is 90°, and it is in horseshoe shape when the impacting angle is 30°. The abrasion weight loss of the ordinary mortar specimen and the E3 mix-proportion specimen increases with impacting time. However, the abrasion weight per unit time (5 minutes) of the two types of materials deceases with the increase of the unit time, and their abrasion processes are different.