The ASTM C1138 "Standard Test Method for Abrasion Resistance of Concrete (Underwater Method)" method aims to reproduce conditions in which flowing water carries solid particles, causing abrasion of the tested concretes. The method uses rotating steel balls to simulate the frictional effect of suspended and bedload particles on the specimen surface. The test setup is composed of a rotating agitation paddle that induces the abrasive forces of the grinding balls. This study focuses on the differences in hydro-abrasion resistance of two cementitious materials, standard concrete and UHPFRC (Ultra High-Performance Fiber Reinforced Cementitious Composite) which is a novel building material used for the rehabilitation and strengthening of concrete structures. High resolution surface scans were performed to characterise the circular material specimens at the end of the test. The results show that UHPFRC has a significantly higher hydro-abrasion resistance than concrete. Lastly, an application of a UHPFRC protection layer on exposed concrete surfaces of a hydropower plant in Switzerland is briefly described.