竹杆生物炭改性水泥土的三轴力学特性研究OA

To investigate the modification effect of bamboo stem biochar on cement-stabilized soil at different curing ages,this study examined the mechanical properties of bamboo stem biochar-modified cement-stabilized soil(BBMCS)specimens,including deviatoric stress-strain curves,peak deviatoric stress,internal friction angle,and cohesion,via unconsolidated-undrained(UU)triaxial tests.The results indicate that bamboo stem biochar improves the morphology of the stress-strain curves of cement-stabilized soil by optimizing its internal structure.The deviatoric stress-strain curves of all BBMCS specimens exhibit strain-softening behavior,characterized by brittle failure.At curing ages of 7 and 28 d,BBMCS specimens with a bamboo stem biochar content of 6%(by mass)demonstrate optimal mechanical properties,with their peak deviatoric stress increasing by 89%and 81%,respectively,compared to the control group without bamboo stem biochar.The enhancement of mechanical properties in BBMCS by bamboo stem biochar is primarily attributed to the improvement of cohesion,with no significant effect observed on the internal friction angle.Based on the experimental data,a quadratic prediction model relating bamboo stem biochar content,confining pressure,and peak deviatoric stress at different curing ages was established.The predicted values show good agreement with the measured values.These findings provide basis for the engineering application of BBMCS.