Author/Authors :
Li، M. L. نويسنده Postdoctor, Nano-structural Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology, Street of Xiao Ling Wei 200, Nanjing 210009, Jiang Su Province, China Li, M. L. , Chun-xiang، Q. نويسنده Professor, East of Ji Yin Da Dao, Jiangning, School of Materials Science and Engineering, Southeast Unvi., Nanjing 211189, Jiang Su Province, China Chun-xiang, Q. , Yong-hao، Z. نويسنده Professor, Executive Director, Nano-structural Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology, Street of Xiao Ling Wei 200, Nanjing 210009, Jiang Su Province, China Yong-hao, Z.
Abstract :
It introduced an innovative bioengineering method of consolidating incompact sand by urea-hydrolysis producing calcite
cementation under the inducement of urease producing microbe. In the paper it discussed the effects of cementation methods
and time on porosity and mechanical properties of microbe-inspired cementing sand columns. Method A adopted reaction fluid
gravitational permeating and external pressing and method B adopted reaction fluid gravitational permeating and outlet
intermittent plugging method. 28-day sand columns prepared by method A exhibited stronger mechanical properties than those
prepared by method B, considering of the compressive strengths and three-point flexural strength as well. Pore volume
fractions of sand columns prepared by method A reduced with an increase in cementation time which represented the bulk
densities of sand columns were improved positively with time. The compressive strengths and the flexural strengths of sand
columns prepared by method A increased with time. All these improved mechanical properties were attributed to the fact that
the increasing amount of microbe inspired calcite precipitation with time consolidated sand columns by filling or bridging in
sand gaps.
