Loose Sand Cemented by Microbial Cementitious Material: Composition, Microstructure and Mechanical Properties

Through the influence of the dosage of culture solution and calcium source on hardness and compressive strength of samples, the formulation of microbial cementitious materials was optimized and defined. The influence of temperature on composition, microstructure and mechanical properties of loose sand cemented by microbial cementitious material was compared and analyzed systematically. With the increase of temperature, the performance of loose sand was improved remarkably. Calcite with cementitious properties could be induced at higher temperatures, but not at lower temperatures. When the temperature was 30 °C, loose sand cemented by microbial cementitious material had more calcite and more dense structure. Moreover, hardness and compressive strength were also superior. The wind tunnel test showed that the wind erosion resistance was improved obviously and the mass loss was lower at high temperature. Engineering properties of loose sand cemented by microbial cementitious material was measured integrally. Through comparative analysis, engineering properties of loose sand were basically unchanged, and there was no negative effect on the later period use of sand.