废弃纤维改良水泥固化土力学特性及破坏模式研究
摘要:水泥固化砂土的低成本、无害化改良是岩土工程领域的热点问题。利用废弃服装制备的涤纶纤维对水泥固化砂土进行改良，研究纤维含量和纤维长度对水泥固化砂土无侧限抗压强度特性的影响。基于试样的宏观破坏形貌，定性分析改良前后水泥固化砂土的破坏模式及破坏模式的转变方式，利用脆性指数，研究纤维含量、纤维长度影响下水泥固化砂土破坏模式的转变规律，定量评价脆性破坏向延性破坏的转变程度。研究结果表明：在最优纤维含量1.0%、最优纤维长度9 mm条件下，废弃涤纶纤维的改良效果最佳，水泥固化砂土的无侧限抗压强度、峰值应变、残余强度、残余应变的增长幅度分别为43.3%、18.2%、276.9%、190.9%。水泥固化砂土改良后，由最初的脆性破坏向半延性、延性破坏转变，宏观破坏形貌由脆性破坏时纵向贯通相互独立的裂隙向半延性破坏时单斜或稀疏的共轭破裂裂纹、延性破坏时稠密的网状共轭裂纹转变。在最优纤维含量、最优纤维长度条件下，试样破坏后表面共轭裂纹数量最多，脆性指数最小，试样由脆性破坏向延性破坏转变程度最高。研究结果为水泥土的无害化改良和纤维土的破坏模式分析提供科学依据。
Abstract:Using a low-cost and environmentally benign method to reinforce cement-stabilized sand is a key issue in geotechnical engineering. Polyester fiber from waste clothes was used to reinforce cement-stabilized sand in this study. The effects of the fiber content and fiber length on the unconfined compressive strength of cement-stabilized sand were examined. The failure modes of the cement-stabilized sand before and after reinforcement were qualitatively analyzed according to the macroscopic damage morphology of a test sample. The impacts of the fiber content and fiber length on changes in the failure mode of the cement-stabilized sand were analyzed according to the brittleness index. The degree of transformation from brittle failure to ductile failure of the cement-stabilized sand was evaluated. The results showed that the optimum reinforcement performance with waste polyester was obtained at a fiber content of 1.0% and fiber length of 9 mm. These conditions realized improvements in the unconfined compressive strength, peak strain, residual strength, and residual strain of the cement-stabilized sand of 43.3%, 18.2%, 276.9%, and 190.9%, respectively. After polyester reinforcement, the failure mode of the cement-stabilized sand gradually transformed from brittle failure to semi-ductile and ductile failure, as reflected by changes in the macroscopic damage morphology. Before reinforcement, the damage morphology consisted of individual cracks extending through the sample in the longitudinal direction, which is typical of brittle failure. After reinforcement, the damage morphology of the sample transformed into unilateral or sparse conjugate cracks representative of semi-ductile failure and dense network-type conjugate cracks representative of ductile failure. Using the optimum fiber content and fiber length yielded the most conjugated cracks on the sample surface, lowest brittleness index, and highest degree of transition from brittle failure to ductile failure. These research results provide a scientific basis for enhancing cement soil with an environmentally benign approach and for analyzing the failure mode of fiber soil.
中文标题：
废弃纤维改良水泥固化土力学特性及破坏模式研究
Mechanical Characteristics and Failure Mode of Wasted Polyester Fiber-reinforced and Cement-stabilized Sand
作者：
仇安兵
Qiu Anbing
作者简介:仇安兵，男，1971年生，汉族，江苏灌云人，高级工程师，主要从事土木工程结构探测及加固处治工作。E-mail：qiuanbing1971@126.com
通讯地址：
北京科技大学，北京 100083
UniversityofScienceandTechnologyBeijing,Beijing100083,China
中图分类号:TU 41
doi:10.3969/j.issn.1007-2993.2022.01.015
出版物：岩土工程技术
收稿日期:2021-01-27
刊出日期:2022-02-16
关键词:废弃涤纶纤维,水泥固化砂土,无侧限抗压强度,破坏模式
Key words:waste polyester fiber,cement-stabilized sand,unconfined compressive strength,failure mode
文档包含图片数量：图片(9)张
文档包含表格数量：表格(3)个
参考文献：
[1]MOHAMMADINIA A,ARULRAJAH A,SANJAYAN J,et al. Laboratory evaluation of the use of cement-treated construction and demolition materials in pavement base and subbase applications[J]. Journal of Materials in Civil Engineering,2015,27(6):04014186.1-04014186.12.
[2]介玉新,王乃东,李广信. 加筋土计算中等效附加应力法的改进[J]. 岩土力学,2007,28(S1):129-132.
[3]杨小礼,李 亮. 条形基础下纤维加筋土地基承载力初探[J]. 地下空间,2000,(1):58-60,80. doi: 10.3969/j.issn.1673-0836.2000.01.013
[4]COOP M R,ATKINSON J H. The mechanics of cemented carbonate sands[J]. Géotechnique,1993,43(1):53-67.
[5]高 磊,胡国辉,杨 晨,等. 玄武岩纤维加筋黏土的剪切强度特性[J]. 岩土工程学报,2016,38(S1):231-237.
[6]陈 乐,刘志彬,周书中. 聚丙烯纤维加筋对高岭土固结压缩特性影响试验研究[J]. 岩土力学,2015,36(S1):372-376.
[7]张 丹,许 强,郭 莹. 玄武岩纤维加筋膨胀土的强度与干缩变形特性试验[J]. 东南大学学报(自然科学版),2012,42(5):975-980. doi: 10.3969/j.issn.1001-0505.2012.05.032
[8]孔玉侠,沈飞凡,王慧娟. 聚丙烯纤维加筋砂土的剪胀特性[J]. 岩土工程学报,2018,40(12):2249-2256.
[9]LIU Y,ZHANG Y,GUO Y,et al. Porous materials composed of flue gas desulfurization gypsum and textile fiber wastes[J]. Waste and Biomass Valorization,2017,8(1):203-207. doi: 10.1007/s12649-016-9617-y
[10]CONSOLI N C,MONTARDO J P,et al. Engineering behaviour of a sand reinforced with plastic waste[J]. Journal of Geotechnical and Geoenvironmental Engineering,2002,128(6):462-472. doi: 10.1061/(ASCE)1090-0241(2002)128:6(462)
[11]CHEN M,SHEN S L,et al. Laboratory evaluation on the effectiveness of polypropylene fibers on the strength of fiber-reinforced and cement-stabilized Shanghai soft clay[J]. Geotextiles and Geomembranes,2015,43(6):515-523. doi: 10.1016/j.geotexmem.2015.05.004
[12]FOOSE G J,BENSON C H,BOSSCHER P J. Sand reinforced with shredded waste tires[J]. Journal of Geotechnical Engineering,1996,122(9):760-767. doi: 10.1061/(ASCE)0733-9410(1996)122:9(760)
[13]HATAF N,RAHIMI M M. Experimental investigation of bearing capacity of sand reinforced with randomly distributed tire shreds[J]. Construction & Building Materials,2006,20(10):910-916.
[14]CAO L,REN H,ZUO J,et al. Mechanical properties of textile fiber modified clay[J]. Jianzhu Cailiao Xuebao/Journal of Building Materials,2014,17(1):110-114.
[15]MIRZABABAEI M. Unconfined compression strength of reinforced clays with carpet waste fibers[J]. Journal of Geotechnical and Geoenvironmental Engineering,2013,139(3):483-493. doi: 10.1061/(ASCE)GT.1943-5606.0000792
[16]ESTABRAGH A R,NAMDAR P,JAWADI A A. Behavior of cement-stabilized clay reinforced with nylon fiber[J]. Geosynthetics International,2012,19(1):85-92. doi: 10.1680/gein.2012.19.1.85
[17]周静海,康天蓓,王凤池. 废弃纤维再生混凝土孔结构及碳化性能分形特征研究[J]. 硅酸盐通报,2017,36(5):1686-1692.
[18]周静海,康天蓓,王凤池,等. 废弃纤维再生混凝土框架中柱节点抗震性能试验研究[J]. 振动与冲击,2017,36(2):235-242.
[19]王建超,张晓芳,周静海,等. 基于分形理论的废弃纤维再生混凝土碳化深度模型[J]. 建筑结构,2019,49(13):137-141.
[20]ASTM. Annual Book of ASTM Standards: Soils and Rock Division[S]. West Conshohocken, Philadelphia. 1998.
[21]ASTM C 150. Standard Specification for Portland Cement, Annual Book of ASTM Standards[S]. ASTM, Philadelphia, PA. 2007.
[22]唐朝生,顾 凯. 聚丙烯纤维和水泥加固软土的强度特性[J]. 土木工程学报,2011,44(S2):5-8.
[23]TANG C S,SHI B,GAO W,et al. Strength and mechanical behavior of short polypropylene fiber reinforced and cement stabilized clayey soil[J]. Geotextiles and Geomembranes,2007,25(3):194-202. doi: 10.1016/j.geotexmem.2006.11.002
[24]ASTM C 187. Standard Test Method for Amount of Water Required for Normal Consistency of Hydraulic Cement Paste[S]. ASTM International, West Conshohocken, PA, USA. 2017.
[25]ASTM C 109. Standard Test Method for Compressive Strength of Hydraulic Cement Mortar[S]. ASTM International, West Conshohocken, PA, USA. 2015.
[26]ASTM C 190. Standard Test Method for Tensile Strength of Hydraulic Cement Mortars[S].
[27]ASTM D 2256. Standard Test Method for Tensile Properties of Yarns by the Single-Strand Method[S]. ASTM International, West Conshohocken, PA, USA.
[28]ASTM D 2101. Test Method for Tensile Properties of Single Man-Made Textile Fiber[S].
[29]HAMIDI A,HOORESFAND M. Effect of fiber reinforcement on triaxial shear behavior of cement treated sand[J]. Geotextiles and Geomembranes,2013,36(1):1-9.
[30]唐朝生,施 斌,高 玮,等. 纤维加筋土中单根纤维的拉拔试验及临界加筋长度的确定[J]. 岩土力学,2009,30(8):2225-2230. doi: 10.3969/j.issn.1000-7598.2009.08.004
[31]史贵才. 脆塑性岩石破坏后区力学特性的面向对象有限元与无界元耦合模拟研究[D]. 武汉: 中国科学院武汉岩土力学研究所, 2005.
[32]王绳祖. 若干固体材料脆–延性转变及宏观结构试验研究[J]. 地球物理学进展,1993,8(4):70-80.
基金项目：
- 文件大小:
- 2.64 MB
- 下载次数:
- 60
-
高速下载
|
|
