A Review of Hydraulic Erosion Mechanisms and Protection Techniques for Concrete in Hydraulic Structures

Hydraulic erosion is a major cause of damage in concrete elements used in high-velocity hydraulic facilities, including spillways, stilling basins, tunnels, and sediment bypass channels. Surface wear develops through the combined action of abrasion, cavitation, turbulence, and moving sediment, gradually weakening concrete and, in difficult situations, impairing serviceability or causing failure. During the past two decades, extensive research has examined the influence of hydraulic conditions, sediment size and concentration, mixture proportions, aggregate type, and the use of fibers or supplementary cementitious materials on erosion resistance. Performance has been investigated through several laboratory approaches, notably ASTM C1138 and water-jet-based techniques that simulate wear mechanisms. More recently, advanced mixtures such as high-performance fiber-reinforced concrete, nano-silica-enhanced concrete, rubberized concrete, and geopolymer-based binders have demonstrated improved matrix compactness and greater mechanical toughness. This review compiles representative findings, compares conventional and emerging concrete types, and explains how both material properties and flow characteristics govern the erosion response. It also highlights unresolved issues, including coupled abrasion-cavitation effects, long-term durability, scale dependency, and the lack of unified standard testing methods for hydraulic concrete. Such insights support more reliable material selection and proportioning in the design of durable hydraulic infrastructure.