Mechanical Behavior of Fiber Reinforced Bio-Cemented Sand: Fid-Bau Portal

Mechanical Behavior of Fiber Reinforced Bio-Cemented Sand

Lv, Chao / Tang, Chao-Sheng

To explore the possibility of providing additional reinforcement to bio-cemented sand through fiber inclusions, a series of laboratory tests were conducted to investigate the effects of the addition of two different types of fibers (polypropylene fiber and basalt fiber) on the mechanical properties of bio-cemented sand, respectively. Samples were prepared at five different fiber ratios (0%, 0.2%, 0.4%, 0.6%, and 0.8% by volume of sand). Unconfined compression tests and calcium carbonate content tests were carried out to characterize the mechanical properties and calcite amounts, respectively. The results show that the unconfined compressive strength (UCS) of basalt fiber-reinforced samples monotonically increases with increasing fiber content, whereas for samples mixed with polypropylene fibers, the UCS increases first and then decreases with increase of fiber content. Moreover, fiber inclusions transit the bio-cemented sand from brittle to ductile failure modes. Scanning electron microscopy (SEM) photographs show that the calcium carbonate precipitations change the surface texture of sand particles and fibers, increase the internal friction, and transform discrete sand particles into a cemented sand cluster.