Concrete erosion mechanism and model research under the action of wind gravel flow in Gobi gale area

Abstract

The surface covering of the Gobi gale area (GGA) primarily consists of medium-coarse sand and gravel, which can easily form a strong wind gravel flow (WGF) under the impact of high winds. Throughout the year, concrete bridge piers are exposed to WGF environments leading to severe erosion damage to their surface. This study investigates the influence of different gravel erosion parameters on concrete erosion wear (CEW) properties investigated through indoor erosion tests. It demonstrates that the concrete erosion rate (CER) initially increases and stabilizes over time. The higher the concrete strength class, the stronger its ability to resist erosion wear. The CER increased with the gravel attack angle and gravel flow. The erosion wind speed positively correlated with the CER, with a speed index between 2.13 and 2.96. When the gravel flow rate was the same, the mass loss of concrete primarily originated from the impact of small gravel. Although the size and depth of the erosion pits on the concrete surface are large under the impact of large-sized gravel, the mass loss is small. In addition, based on the bitter-deformation wear theory and the Oka erosion model, a concrete erosion model suitable for the WGF in Gobi was established. This study provides significant guidance for the protection and quality assurance of concrete structures in GGA.