Study on the resistance of basalt fiber concrete to erosion of building structure by wind gravel flow

Abstract

Concrete structures in the windy regions of the Gobi face constant erosion from wind gravel flow, leading to severe surface damage and significantly reduced durability. This paper investigates the erosion resistance of basalt fiber (BF) concrete under various erosion conditions using the air-flow sand injection method. The results indicate that adding 0.15% BF to concrete reduces its erosion rate by 20.7% to 21.5% compared to concrete without BF. Therefore, a BF content of 0.15% provides optimal erosion resistance for the concrete. The correct amount of BF bonds tightly with the cement mortar, forming a mesh structure inside the concrete that absorbs the kinetic energy of gravel impacts. The concrete erosion process can be divided into an early accelerated phase and a later stabilized phase. Throughout these phases, the erosion rate of concrete increases with the erosion angle (EA), erosion wind speed (EWS), and gravel flow rate (GFR). In particular, the erosion rate of BF15 concrete increased by 35.6 to 46.4mg/cm² when the EA changed from 15° to 90°. Notably, surface damage from low-angle erosion mainly consists of cut scratches, while high-angle erosion primarily results in erosion pits. As the grain size of the eroded gravel increases, the erosion rate of the concrete decreases. However, when a single large gravel particle impacts the concrete, it creates a larger and deeper erosion pit. Furthermore, the erosion rate of BF concrete exhibits a strong negative linear correlation with its mechanical properties, with an R² value exceeding 0.88. Moreover, erosion reduces both compressive and splitting tensile strengths of concrete. For BF15 concrete, however, the decreases are minimal: compressive strength drops by just 1.2MPa, and splitting tensile strength decreases by only 0.2MPa. Building on Bitter and Neilson’s theoretical erosion model, an improved erosion model for BF concrete has been developed under wind gravel flow. This model incorporates the BF mixing factor and particle size function while considering other erosion parameters comprehensively. The enhanced model provides a theoretical foundation and scientific basis for safeguarding concrete structures in Gobi wind-prone regions.