Effect of Basalt Fiber on the Strength Properties of Polymer Reinforced Sand

This paper displays an experimental study of the effect of basalt fiber on the strength properties of polymer reinforced sand. Laboratory trials of unconfined compression test (UCS), direct shear test, and tensile test were conducted on the specimens treated with polymer and basalt fiber, and several factors including polymer content, fiber content and dry density of sand that will influence the strength behaviors are investigated in detail. Based on test results and scanning electron microscope (SEM) images, the reinforcement mechanism was analyzed. The results showed that the polymer content, basalt fiber content and dry density of sand had greatly improved the strength behaviors of reinforced specimens. The increase in polymer and fiber content had an active effect on strength characteristics, while the angle of internal decreased slightly. The strength properties were enhanced with the increase in dry density, and the effect of dry density on tensile strength is affected by fiber content. The presence of randomly distributed fibers has formed a spatial fiber-sand net in sand, and the additive of polymer solution formed membrane to enwrap sand particles and connect sand and fibers, thereby formed a stable structure in sand. These structures have increased the bonding and interlocking forces between sand and fibers, and decreased the void ratio of reinforced specimens.