According to the fiber bridging theory, fiber plays an important role in stress transfers of matrix, transferring the stress at the crack to the surrounding matrix. However, the high cost of PVA fibers hinders their practical application, especially in China. Polyvinyl alcohol (PVA) fibers show good potential in reinforce cemented soil due to their high strength, chemical corrosion resistance, good elasticity, wear resistance, and uniform dispersion. Many researchers attempted to improve its mechanical properties by adding short fibers into cemented soils.
This conventionally includes 10–20% cement, and thus has some common shortcomings stemming from the use of cement, i.e., poor flexural properties, rapid crack propagation after cracking and a high risk of brittle failure.
Lastly, scanning electron microscope (SEM) and mercury intrusion porosimetry tests were adopted to reveal the mechanism of bending performance in cemented soils reinforced by fiber surface modifications.Ĭemented soils retaining wall are a typical type of foundation pit support in soft soil areas. In addition, the crack tip strain, crack propagation rate and the initial crack width of the modified specimens were lower than those before modification. The results show that all fiber surface modifications increased peak strength and fracture energy, for example, the fracture energy of specimens AN1, AH1 and AK1 was increased by 180.4%, 121.5% and 155.4%, respectively, compared to PVA1. The digital image correlation (DIC) technology was used to examine the crack propagation process and the strain field distribution of cracks in specimens in the flexural tests. In this study, how different fiber surface modifications, i.e., alkali treatment, acid treatment and silane coupling agent treatment, as well as different fiber contents, i.e., 0%, 0.25%, 0.5% and 1%, affect the bending properties of cemented soils was investigated by conducting three-point bending tests on notched beams. To improve the flexural properties of cemented soils reinforced with fibers and avoid their brittle failure when subjected to complex loading conditions, a simple and cost-effective technique was explored to facilitate their application in retaining walls.
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