废弃口罩加筋酶诱导碳酸盐沉淀固化砂土的抗剪强度特性
Shear strength characteristics of sand solidified by enzyme-induced carbonate precipitation with waste face mask reinforcement
张建伟 1李想 2韩智光 2边汉亮2
作者信息
- 1. 河南大学 土木建筑学院,开封 475004;开封市特殊土改性与修复工程技术研究中心,开封 475004
- 2. 河南大学 土木建筑学院,开封 475004
- 折叠
摘要
为进一步提升酶诱导碳酸盐沉淀(EICP)固化砂土的抗剪强度特性,改善固化砂土的脆性破坏特征,向未固化砂土中添加废弃的一次性口罩进行改良.基于三轴压缩试验等,研究不同口罩纤维掺量对EICP固化砂土抗剪强度的影响,并分析改变EICP滴注轮次和砂土初始相对密实度后,改良砂土的抗剪强度特性和口罩加筋效益的变化情况.结果表明:口罩最优掺量为 0.2%,不同围压下可以使改良砂土的峰值偏应力提高 59.9%～34%,黏聚力提高 188%,内摩擦角提高 14.5%,且能有效减少峰后强度损失,改善固化砂土的脆性破坏特征;增加滴注轮次和相对密实度可以提高峰值偏应力、黏聚力和内摩擦角,但口罩的加筋效果略微减弱;碳酸钙生成率随滴注轮次增加而增大,随相对密实度增加而减小,加筋可以提高碳酸钙生成率.
Abstract
To further enhance the shear strength characteristics of sandy soils cured by enzyme-induced carbonate precipitation(EICP)technology,and to improve the brittle damage characteristics of the cured sandy soils,the abandoned disposable masks were blended into the sandy soils for improvement.Based on the triaxial compres-sion test,the influence of different contents of the mask on the shear strength of EICP solidified sand was studied.However,the change of the shear strength characteristics of improved sand and the benefit of mask reinforcement were analyzed after changing the EICP drip rounds and the initial relative compactness of sand.The results show that the best content of the mask is 0.2%.At this time,the peak partial stress of improved sandy soil increases by 59.9%-34%under different confining pressures,the cohesive force increases by 188%,and the internal friction angle increases by 14.5%.The post-peak strength loss is effectively reduced and the brittle damage of cured sand is im-proved.However,increasing the number of drip rounds and relative compactness could increase the peak partial stress,cohesive force and internal friction angle,but the effect of mask reinforcement is slightly weakened.Finally,mask reinforcement can improve the calcium carbonate generation rate,and the calcium carbonate generation rate increases with the increase of drip rounds,but decreases with the increase of relative compactness.
关键词
EICP/抗剪强度/黏聚力/内摩擦角/碳酸钙生成率/聚丙烯纤维/废弃口罩Key words
EICP/shear strength/cohesion force/internal friction angle/calcium carbonate formation rate/polypropylene fiber/discarded masks引用本文复制引用
基金项目
国家自然科学基金(42177454)
河南省自然科学基金(232300420073)
河南省研究生教育改革与质量提升工程项目(YJS2021JD13)
出版年
2024
NETL
NSTL
维普
万方数据