摘要
为了研究冻融循环次数、纤维掺量和冻结温度对水泥改良风积沙劈裂抗拉强度的影响,开展玄武岩纤维水泥改良风积沙试样的冻融循环试验和劈裂抗拉强度试验。试样的纤维掺量分别为0,0.5%,0.8%和1.1%。冻结试验的冻结温度分别为−10℃,−20℃和−30℃,融化温度为20℃。试验结果表明,纤维水泥改良风积沙的劈裂抗拉强度随着冻融循环次数的增加而减少,与未经冻融循环的试样比较,第1次、第1~2次、第2~4次、第4~7次和第7~10次冻融循环后,每次冻融循环的强度损失速率分别为18.7%~36.8%,16.8%~21.0%,2.9%~6.5%,4.0%~5.8%和1.5%~2.7%,10次冻融循环后强度损失速率趋近于0。经历冻融循环后,纤维水泥改良风积沙试样的劈裂抗拉强度随着纤维掺量的增大而增大,达到0.8%的最优纤维掺量后则相反。纤维水泥改良风积沙试样劈裂抗拉强度随着冻结温度的降低而减小,但减小的幅度不明显。劈裂抗拉强度与冻融循环次数呈指数函数关系,与纤维掺量呈抛物线关系。劈裂抗拉强度影响因素相关性分析结果表明,劈裂抗拉强度与冻融循环次数呈负相关,而与纤维掺量、冻结温度呈正相关,冻融循环次数对劈裂抗拉强度的影响最显著,其次为纤维掺量,而冻结温度影响最小。基于108组实验数据,采用多元非线性回归分析法,建立劈裂抗拉强度的多因素评估模型,能够较好地预测不同冻融循环次数和纤维掺量下水泥改良风积沙的劈裂抗拉强度。研究成果可为风积沙铁路路基基床设计提供参考。
The main objective of this study was to determine the effects of basalt fiber(BF)content(0%,0.5%,0.8%,1.1%),number of freeze-thaw(F-T)cycles(0,1,2,4,7,10,14,18 and 20),and freezing temperature(-10℃,-20℃,-30℃)on the splitting tensile strength(STS)of cement-stabilized aeolian sand reinforced with fiber(CSASRF).A series of F-T cycle tests without water supply condition were conducted on CSASRF after standard curing for 28 days,subsequently.The STS tests were carried out.Results show that STS of CSASRF decreases with increasing F-T cycles number.Compared with the samples of CSASRF without F-T cycle,the samples are subjected to the 1st,1st~2nd,2nd~4th,4th~7th and 7th~10th F-T cycles,the splitting tensile strength loss rates(STSLR)of samples are 18.7%~36.8%,16.8%~21.0%,2.9%~6.5%,4.0%~5.8%,1.5%~2.7%,respectively.The STSLR tends to zero after ten F-T cycles.The STS of CSASRF specimens after F-T cycles display more tensile strength due to fiber reinforcing,and the strength increased monotonically with the increase of fiber content until 0.8%fiber content,after which the peak tensile strength decreased.The STS of CSASRF decreases with the freezing temperature,but the decrease is not significant.The STS of CSASRF and the number of F-T cycle shows an exponential function,and shows a parabolic relationship with fiber content.The STS of CSASRF is negatively correlated with F-T cycle number,but positively correlated with the fiber content and freezing temperature.F-T cycle number is the most effective parameter affecting on STS of CSASRF followed by fiber content and least freezing temperature.Based on 108 experimental data,the multiple nonlinear regression model(MNLR)by considering the effects of numbers F-T cycles and fiber content for prediction STS of CSASRF is proposed,and predicted values are consistent with the experimental data.
作者
阮波
程焱
路占海
张向京
聂如松
RUAN Bo;CHENG Yan;LU Zhanhai;ZHANG Xiangjing;NIE Rusong(School of Civil Engineering,Central South University,Changsha 410075,China;Hunan Tieyuan Civil Engineering Testing Co.,Ltd.,Central South University,Changsha 410004,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2023年第7期2521-2529,共9页
Journal of Railway Science and Engineering
基金
中国铁路乌鲁木齐局集团有限公司科技研究开发计划课题(WLMQ-KGHZGS-HRTL-GGB-2020-0032)
国家自然科学基金资助项目(51878666,51978672)
中南大学实验室开放专项资金资助项目(160160001)。
作者简介
通信作者:聂如松(1980-),男,湖南衡阳人,副教授,博士,从事岩土工程教学与科研工作,E−mail:nierusong97@csu.edu.cn。
