Investigation of tensile strength and deformation behaviors of basalt fiber-reinforced loess subjected to dry-wet cycles

The frequent occurrence of geological disasters in the Loess Plateau is related to the low tensile strength of the loess. Previous studies on fiber-reinforced loess mainly focused on compressive properties, and there have been fewer studies on tensile behaviors, especially when subjected to dry-wet cycles. In this paper, the tensile strength and deformation behaviors of basalt fiber-reinforced loess in the range of 0 to 10 dry-wet cycles were studied by uniaxial tensile test combining digital image correlation (DIC) technology. The results reveal that the unreinforced loess has no visible post-peak curve and brittle fracture occurs, while the reinforced loess has a residual strength and shows distinct ductile failure. The uniaxial tensile strength (UTS) of reinforced loess decreases with dry-wet cycles, but the decay rate decreases. The resistance of reinforced loess to dry-wet action is better than loess, with an optimal fiber content of 0.6%. The variation of failure strain of reinforced loess is consistent with UTS with a linear correlation between the two, indicating that the strength is directly related to its deformation resistance. The maximum axial strain in the surface strain field of reinforced loess shows an increasing trend with dry-wet cycles and a decreasing and then increasing trend with fiber content, which is opposite to UTS and failure strain. Fiber reinforcement improves the plastic properties of loess, and the deformation of reinforced loess is more uniform. This study reveals the deterioration law of reinforced loess under dry-wet cycles, providing theoretical support for engineering construction in loess areas.