粉煤灰充填材料早龄期物理力学特性及其水化过程分析
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摘要
针对粉煤灰充填材料早期强度低、变形量大、流动性差、泌水严重等缺陷,基于电阻率法和力学特性测试法研究3种配比粉煤灰充填材料早龄期的体积电阻率、孔隙溶液电阻率、单轴抗压强度和弹性模量随时间的变化规律;结合充填材料初始孔隙度和1 d孔隙度的测试结果,对孔隙度随时间的变化规律作进一步分析。结果表明:(1)材料的体积电阻率随时间呈升高、降低、再升高的变化规律,孔隙溶液的电阻率随时间呈先急剧下降后趋于稳定的变化规律,但材料的电阻率变化在时间上和数值上受粉煤灰掺量的影响;(2)材料的单轴抗压强度和弹性模量随水化时间的延长而增大,随粉煤灰掺量的增加而降低;(3)材料的孔隙度随水化时间的延长呈负指数规律降低,随粉煤灰掺量的增加先降低后增加;(4)在水化后期,材料的单轴抗压强度和弹性模量与其体积电阻率呈对数相关;(5)材料早龄期的水化过程可分为吸附期、溶解期、凝结期和硬化期4个阶段。研究结果为进一步了解、改善粉煤灰充填材料早龄期的物理力学特性和实现材料特性的无损检测提供了一定的理论与应用参考。
Fly ash filling materials at early age have low strength,large deformation,poor liquidity and severe water bleeding. Several experiments on the fly ash filling materials with three different mixing ratios at early age were carried out to study the bulk electrical resistivity,the electrical resistivity of pore solution,the uniaxial compressive strength and the elastic modulus varied with time. The porosity variation with time was analyzed with the initial porosity and measured 1 d porosity of the filling material. The bulk resistivity was found to increase-decrease-increase with time. The resistivity of pore solution decreased firstly then tended to a stable value. Both the bulk resistivity and the resistivity of pore solution were influenced by the dosage of fly ash. The uniaxial compressive strength and elastic modulus increased with the extending of the hydration time,but decreased with the increase of the dosage of fly ash. The porosity decreased inversely exponentially with the extending of hydration time and decreased firstly then increased with the dosage of fly ash. In the late age of hydration,both the uniaxial compressive strength and elastic modulus were related to bulk resistivity logarithmically. The hydration process at early age can be divided into four stages,such as adsorption period,a dissolution period,setting period and hardening period.
Fly ash filling materials at early age have low strength,large deformation,poor liquidity and severe water bleeding. Several experiments on the fly ash filling materials with three different mixing ratios at early age were carried out to study the bulk electrical resistivity,the electrical resistivity of pore solution,the uniaxial compressive strength and the elastic modulus varied with time. The porosity variation with time was analyzed with the initial porosity and measured 1 d porosity of the filling material. The bulk resistivity was found to increase-decrease-increase with time. The resistivity of pore solution decreased firstly then tended to a stable value. Both the bulk resistivity and the resistivity of pore solution were influenced by the dosage of fly ash. The uniaxial compressive strength and elastic modulus increased with the extending of the hydration time,but decreased with the increase of the dosage of fly ash. The porosity decreased inversely exponentially with the extending of hydration time and decreased firstly then increased with the dosage of fly ash. In the late age of hydration,both the uniaxial compressive strength and elastic modulus were related to bulk resistivity logarithmically. The hydration process at early age can be divided into four stages,such as adsorption period,a dissolution period,setting period and hardening period.
引文
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[3]胡炳南.我国煤矿充填开采技术及其发展趋势[J].煤炭科学技术,2012,40(11):1–5.(HU Bingnan.Backfill mining technology and development tendency in China coal mine[J].Coal Science and Technology,2012,40(11):1–5.(in Chinese))
[4]赵才智.煤矿新型膏体充填材料性能及其应用研究[博士学位论文][D].徐州:中国矿业大学,2008.(ZHAO Caizhi.Study on coal mine new paste filling material properties and its application[Ph.D.Thesis][D].Xuzhou:China University of Mining and Technology,2008.(in Chinese))
[5]赵才智,周华强,瞿群迪,等.膏体充填材料力学性能的初步实验[J].中国矿业大学学报,2004,33(2):159–161.(ZHAO Caizhi,ZHOU Huaqiang,QU Qundi,et al.Preliminary test on mechanical properties of paste filling material[J].Journal of China University of Mining and Technology,2004,33(2):159–161.(in Chinese))
[6]牛海丽,胡术刚,吕宪俊,等.煤矿膏体充填胶结材料试验研究[J].混凝土,2009,(12):79–82.(NIU Haili,HU Shugang,LU Xianjun,et al.Experiment on cementation material for coal mine paste filling[J].Concrete,2009,(12):79–82.(in Chinese))
[7]董慧珍.采空区充填料浆及其管道输送特性试验研究[硕士学位论文][D].太原:太原理工大学,2013.(DONG Huizhen.Experimental study on filling slurry of goaf and transportation characteristic of pipeline[M.S.Thesis][D].Taiyuan:Taiyuan University of Technology,2013.(in Chinese))
[8]刘进晓,刘伟韬,穆玉兵,等.矸石膏体优化配比及其力学性能基础试验研究[J].矿业安全与环保,2014,41(2):28–31.(LIU Jinxiao,LIU Weitao,MU Yubing,et al.Basic experiment and study on optimal proportioning and mechanical properties of waste paste[J].Mining Safety and Environmental Protection,2014,41(2):28–31.(in Chinese))
[9]MCCARTER W J,TRAN D.Monitoring pozzolanic activity by direct activation with calcium hydroxide[J].Construction and Building Materials,1996,10(3):179–184.
[10]MCCARTER W J,CHRISP T M,STARRS G,et al.Characterization and monitoring of cement-based systems using intrinsic electrical property measurements[J].Cement and Concrete Research,2003,33(2):197–206.
[11]魏小胜,肖莲珍,李宗津.采用电阻率法研究水泥水化过程[J].硅酸盐学报,2004,32(1):34–38.(WEI Xiaosheng,XIAO Lianzhen,LI Zongjin.Study on hydration of Portland cement using an electrical resistivity method[J].Journal of the Chinese Ceramic Society,2004,32(1):34–38.(in Chinese))
[12]魏小胜,肖莲珍,崔登国,等.早龄期混凝土的力学和电性能研究[J].武汉理工大学学报,2008,30(6):52–55.(WEI Xiaosheng,XIAO Lianzhen,CUI Dengguo,et al.Early age investigation of mechanical and electrical properties[J].Journal of Wuhan University of Technology,2008,30(6):52–55.(in Chinese))
[13]魏小胜,肖莲珍.用电阻率法确定混凝土结构形成的发展阶段及结构形成动力学参数[J].硅酸盐学报,2013,41(2):171–179.(WEI Xiaosheng,XIAO Lianzhen.Determination and kinetics parameters of structure formation periods of concrete by electrical resistivity measurement[J].Journal of the Chinese Ceramic Society,2013,41(2):171–179.(in Chinese))
[14]PRINCIGALLO A,VAN BREUGEL K,LEVITA G.Influence of the aggregate on the electrical conductivity of Portland cement concretes[J].Cement and Concrete Research,2003,33(11):1 755–1 763.(in Chinese))
[15]FERREIRA R M,JALALI S.NDT measurements for the prediction of28-day compressive strength[J].NDT and E International,2010,43(2):55–61.
[16]LüBECK A,GASTALDINI A L G,BARIN D S,et al.Compressive strength and electrical properties of concrete with white Portland cement and blast-furnace slag[J].Cement and Concrete Composites,2012,34(3):392–399.
[17]肖莲珍,李宗津,魏小胜.用电阻率法研究新拌混凝土的早期凝结和硬化[J].硅酸盐学报,2006,33(10):1 271–1 275.(XIAO Lianzhen,LI Zongjin,WEI Xiaosheng.Early setting and hardening process of young concrete using the resistivity measurement[J].Journal of the Chinese Ceramic Society,2006,33(10):1 271–1 275.(in Chinese))
[18]查甫生,刘松玉,杜延军,等.电阻率法评价膨胀土改良的物化过程[J].岩土力学,2009,30(6):1 711–1 718.(ZHA Fusheng,LIU Songyu,DU Yanjun,et al.Evaluation of physicochemical process in stabilized expansive soils using electrical resistivity method[J].Rock and Soil Mechanics,2009,30(6):1 711–1 718.(in Chinese))
[19]章定文,曹智国,张涛,等.碳化对水泥固化铅污染土的电阻率特性影响规律[J].岩石力学与工程学报,2014,33(12):2 563–2 572.(ZHANG Dingwen,CAO Zhiguo,ZHANG Tao,et al.Effect of carbonation on electrical Resistivity of cement solidified lead-contaminated soils[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(12):2 563–2 572.(in Chinese))
[20]章定文,曹智国,刘松玉.固化土电阻率变化规律与经验模型[J].岩石力学与工程学报,2014,33(增2):4 139–4 144.(ZHANG Dingwen,CAO Zhiguo,LIU Songyu.Characteristics and an experiential model of electrical resistivity of stabilized soils[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(Supp.2):4 139–4 144.(in Chinese))
[21]钱觉时.粉煤灰特性与粉煤灰混凝土[M].北京:科学出版社,2002:18–21.(QIAN Jueshi.Characteristics of fly ash and fly ash concrete[M].Beijing:Science Press,2002:18–21.(in Chinese))
[22]向宇.煤矸石的基本性质及作为橡胶补强填充剂的基础性研究[硕士学位论文][D].太原:太原理工大学,2004.(XIANG Yu.The basic properties of coal shales and basic study on using coal shales as the filler of rubber[M.S.Thesis][D].Taiyuan:Taiyuan University of Technology,2004.(in Chinese))
[23]魏小胜,田凯,田冠飞,等.电阻率法研究大掺量粉煤灰净浆的吸附效应[J].武汉理工大学学报,2008,30(12):33–36.(WEI Xiaosheng,TIAN Kai,TIAN Guanfei,et al.Research on adsorption effect of high volume fly ash paste using electrical resistivity method[J].Journal of Wuhan University of Technology,2008,30(12):33–36.(in Chinese))
[24]王冲,杨长辉,钱觉时,等.粉煤灰与矿渣的早期火山灰反应放热行为及其机理[J].硅酸盐学报,2012,40(7):1 050–1 058.(WANG Chong,YANG Changhui,QIAN Jueshi,et al.Behavior and mechanism of pozzolanic reaction heat of fly ash and ground granulated blastfurnace slag at early age[J].Journal of the Chinese Ceramic Society,2012,40(7):1 050–1 058.(in Chinese))
[25]隋同波,曾晓辉,谢友均,等.电阻率法研究水泥早期行为[J].硅酸盐学报,2008,(4):431–435.(SUI Tongbo,ZENG Xiaohui,XIE Youjun,et al.Early age cement hydration behavior by resistivity method[J].Journal of The Chinese Ceramic Society,2008,(4):431–435.(in Chinese))
[26]韩冀豫.高掺量粉煤灰水泥水化产物CSH凝胶聚合程度的研究[硕士学位论文][D].武汉:武汉理工大学,2011.(HAN Jiyu.Research on silicon-oxy tetrahedron aggregate states of hydration products CSH gels of cement with high content of fly ash materials[M.S.Thesis][D].Wuhan:Wuhan University of Technology,2011.(in Chinese))
[27]ARCHIE G E.The electrical resistivity log as an aid in determining some reservoir characteristics[J].Transactions of the AIME,1942,146(1):54–62.
[28]孙建国.阿尔奇(Archie)公式:提出背景与早期争论[J].地球物理学进展,2007,(2):472–486.(SUN Jianguo.Archie’s formula:historical background and earlier debates[J].Progress in Geophysics,2007,(2):472–486.(in Chinese))
[29]荆万学,陈永吉.浅探阿尔奇公式的物理学原型[J].测井技术,1997,(4):57–59.(JING Wanxue,CHEN Yongji.On the original physical model of Archie formulap[J].Well Logging Technology,1997,(4):57–59.(in Chinese))
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