摘要
双碳战略下开展资源综合利用极为迫切。为提升粉黏土力学强度特性,提出以矿渣、炉渣、石膏三种工业废渣为基础原料,在生石灰碱性环境下协同激发制备废渣基地聚合物,用以固化稳定粉黏土改良其工程特性。通过开展无侧限抗压强度试验与X射线衍射(X-ray diffraction,简称XRD)微观测试试验,分析了不同废渣地聚物掺量下试样变形特性,并探讨了养护方式、掺加纤维、养护龄期对试样性能的影响规律。同时,研究了试样的水化产物种类,并依托实际工程铺筑了废渣地聚物稳定粉黏土基层试验路段。得到如下主要结论:废渣地聚物稳定粉黏土最优掺量为15%,其中矿渣:炉渣:生石灰:石膏配合比为8:2:3:2,聚丙烯纤维掺量为0.2%,养护方式为6 d标养+1 d浸水;此条件下试样力学性能得到显著提高,纤维加筋作用提升了试样应力-应变曲线第3阶段韧性区域。试样水稳性能优异,适当延长浸水养护龄期更有利于试样强度增加,水稳系数最高达200%。纤维、废渣地聚物水化凝胶与土颗粒三者之间紧密搭接形成了致密的三维网状结构,增强了纤维-水化凝胶组分-土颗粒界面力学强度。此外,试样固化时间效应显著,28 d强度增长率达80%~188%。研究为实现工业废渣、粉黏土绿色低碳应用提供基础依据与科学参考。
It is extremely urgent to implement comprehensive resource utilization within the framework of the dual carbon strategy.To improve the mechanical strength properties of silty clay,three types of industrial waste slag,such as slag,bottom ash and gypsum,are utilized as primary raw materials.A waste slag-based geopolymer is then prepared through synergistic activation in an alkaline quicklime environment to stabilize the silty clay and enhance its engineering characteristics.The deformation characteristics of samples under varying waste residue geopolymer content were analyzed through unconfined compressive strength tests and X-ray diffraction(XRD)microscopic tests.The study compared and examined the influence of curing method,fiber addition,and curing age on sample performance,as well as explored the types of hydration products present.A test section of waste residue geopolymer-stabilized silty clay base was constructed for the actual project.The key findings suggest that the optimal dosage of waste slag geopolymer-stabilized silt clay is 15%,with a slag:bottom ash:quicklime:gypsum mix ratio of 8:2:3:2,polypropylene fiber content of 0.2%,and a curing method of 6 d standard curing followed by 1 d of soaking.The mechanical properties of the samples show significant improvement,particularly in the toughness region of the stress-strain curve due to fiber reinforcement.The samples exhibit excellent water stability,and extending the immersion curing age appropriately enhances the sample’s strength,with a water stability coefficient reaching up to 200%The fibers,waste residue geopolymer hydration gel and soil particles interlock closely to create a dense three-dimensional network structure,thereby enhancing the mechanical strength of the fiber-hydration gel component-soil particle interface.The curing time significantly impacts the sample,with a strength growth rate ranging from 80%to 188%at 28 d.
作者
沈君
程寅
金小平
斯纪平
杨天军
于浩
余昆
SHEN Jun;CHENG Yin;JIN Xiao-ping;SI Ji-ping;YANG Tian-jun;YU Hao;YU Kun(Engineering Center,China Academy of Transportation Sciences,Beijing 100029,China;Zhejiang Communications Construction Group Co.,Ltd.,Hangzhou,Zhejiang 310051,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2024年第S01期147-156,共10页
Rock and Soil Mechanics
基金
国家自然科学基金(No.52268072)
交通运输行业重点科技项目(No.2021-TG-011)
中央公益性科研院所基本业务费项目(No.20227501)
关键词
工业废渣
地聚合物
固化稳定
无侧限抗压强度
industrial waste residue
geopolymer
solidification and stabilization
unconfined compressive strength
