Experimental study on the strength of loess solidified by soybean urease-induced calcium carbonate precipitation
Soybean urease-induced carbonate precipitation(SICP)is a technology for microbial mineralization of plant enzymes.The unconsolidated undrained triaxial test was conducted on the solidified loess at a cementation solution concentration of 0-4.5 mol/L to explore the prospect of its application in loess engineering.The strength and stress-strain relationship of loess before and after solidification were analyzed,and the microstructure changes and mineral composition of lo-ess before and after solidification were also tested via SEM and XRD.The results show that the strength of loess first increases and then decreases with the rise in the cementation solution con-centration,revealing the maximum value when the concentration of cementation solution is 2.5 mol/L.The strength of loess is substantially increased by the solidification of SICP,revealing a maximum value of 2 066.63 kPa,which is at least 1.31 times larger than that of unconsolidated soil.The SEM test results show that the calcium carbonate crystals generated by SICP can fill the pores of soil and cement some soil particles,thus improving the strength of the soil.The XRD test results reveal that the main mineral composition of loess remains unchanged before and after solidification,while the number and height of diffraction peaks of calcium carbonate crystals drastically increase after solidification.Overall,these results can provide new ideas for the appli-cation of SICP technology for loess solidification.
万方数据
维普
