基体材料对铁路沿线风积沙ECC性能影响研究  

Influence of matrix material on performance of ECC with aeolian sand along railway

作　　者：梁轩 程建军[1] 夏多田[1] 张朵 武海洋 陈驰 LIANG Xuan;CHENG Jianjun;XIA Duotian;ZHANG Duo;WU Haiyang;CHEN Chi(College of Water Conservancy&Architectural Engineering,Shihezi University,Shihezi 832003,China;Jinchuan Nickel Cobalt Research&Design Institute Co.,Ltd.,Jinchang 737100,China)

机构地区：[1]石河子大学水利建筑工程学院,新疆石河子832003 [2]金川镍钴研究设计院有限责任公司,甘肃金昌737100

出　　处：《铁道科学与工程学报》2024年第3期1025-1036,共12页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52168026)。

摘　　要：为解决沙漠戈壁地区河砂资源紧缺、运输成本高等问题,同时减轻沙漠铁路风沙灾害,开展沙漠铁路沿线原状风积沙制备地域性工程水泥基复合材料(ECC)的试验研究。通过正交试验探究了不同风积沙掺量(S/C)、粉煤灰掺量(FA/C)和水胶比对ECC性能的影响,对三点弯曲试验的试件进行了开裂形态及荷载-挠度曲线的比较,并对流动度、表观密度、力学性能以及韧性进行了极差分析,结合微观分析初步确定出合理的基体配合比;在此基础上进一步探究了不同粉煤灰掺量对ECC抗压性能、弯曲性能、拉伸性能和变形能力的影响。研究结果表明:风积沙对流动度、弯曲性能影响最显著,粉煤灰对表观密度、抗压性能影响最显著;当风积沙掺量为0.75、粉煤灰掺量为1.50、水胶比为0.34时材料的综合性能最好,即流动度、抗压抗折强度分别为:151 mm、50.1 MPa和17.3 MPa;粉煤灰掺量从1.50增加到3.50时,材料极限拉应变在2%~3.5%范围内波动,掺量为2.50时极限拉应变出现最大值3.5%;当掺量为3.0时轴拉试件裂缝宽度最小为100μm,此时裂缝数量最多、间距最小。风积沙掺量为0.75、粉煤灰掺量为1.5时纤维表面有明显划痕且附着水化产物,纤维在基体中能较好地发挥桥联作用;水胶比为0.36时基体密实度较低,对纤维的锚固作用会被削弱。研究为风积沙在沙漠地区铁路工程中制备高延性混凝土提供了一定的理论依据。In order to solve the problems of scarce river sand and high transportation costs in the Gobi desert region,and to mitigate desert railway wind-sand disasters,the experimental study on the preparation of regional engineered cementitious composites(ECC)along the desert railway was carried out.The effects of different aeolian sand content(S/C),fly ash content(FA/C),and water-binder ratio on the performance of ECC were measured by orthogonal tests.A reasonable mix design was determined initially based on the cracking form and load-deflection curves of three-point bending tests,the fluidity,apparent density,mechanical properties,and toughness of the range analysis,and microscopic analysis.On the basis,the effects of different fly ash content on the compressive properties,bending properties,tensile properties,and deformation capacity of ECC were further explored.Fluidity and bending properties were affected most by the aeolian sand,and the fly ash had the most significant effect on the apparent density and compressive properties.The overall properties of the material were best when the content of aeolian sand was 0.75,fly ash was 1.50,and the water-binder ratio was 0.34.With those values the fluidity,compressive strength,and flexural strength were 151 mm,50.1 MPa,and 17.3 MPa,respectively.The ultimate tensile strain of the material fluctuated between 2%and 3.5%when the fly ash content was increased from 1.50 to 3.50,and the maximum value of 3.5%appeared when the fly ash content was 2.50.The minimum crack width of axial tensile specimen was 100μm when the fly ash content was 3.0 and the number of cracks was the largest and the spacing was the smallest.The fiber surface had obvious scratches and attached hydration products when the aeolian sand content was 0.75 and fly ash content was 1.5,the fiber could better exert a bridging effect in the matrix.The matrix density was lower when the water-binder ratio was 0.36,and the anchoring effect of the matrix on the fibers was weakened.The research results can provide a theore

关 键 词：ECC 风积沙 粉煤灰 力学性能 微观分析 沙漠铁路 

分 类 号：TU528[建筑科学—建筑技术科学]