摘要
水泥固化软土是工程中一种常见的地基处理方法。然而众多工程实践表明,仅利用水泥加固软土,其早期强度偏低,且随着养护龄期的增长水泥固化土体积收缩,易造成工程土体的沉降和开裂等问题。本研究选用玄武岩纤维与水泥共同固化软土,探究玄武岩纤维对水泥固化土强度以及收缩性能的影响。本试验制备了不同水泥掺量、不同玄武岩纤维掺量的固化土试样,对各龄期条件下试样的无侧限抗压强度及收缩性质进行测试,结合力学性质及收缩特征,确定最佳的水泥及纤维掺量。并结合试样的微观结构特征来分析,考虑纤维对水泥固化土强度及收缩变形影响的机理。结果表明:纤维的加入能有效提高水泥土的强度,改善其收缩性。纤维在试样中随机离散分布,纤维的存在可起到一种“桥梁”作用,与水泥的水化产物一起充填于土样孔隙中,使得土颗粒间充分连接起来,限制了颗粒间的位移,提高了试样的强度,抑制了试样的收缩,提高了土体整体的稳定性。研究成果可为软土的有效固化处理及高效利用提供理论及实践参考。
Cement solidified soft soil is a common foundation treatment method in engineering.However,many engineering practices have shown that the early strength of soft soil reinforced by cement alone is low,and the volume of cement solidified soil shrinks with the growth of the curing age.They are likely to cause settlement and cracking of the engineering soil mass.We used basalt fibers to solidify soft soils with cement to explore the effect of basalt fibers on the strength and shrinkage performance.We prepared the different cement and basalt fibers solidified soil samples in this experiment.Under various age conditions,we tested the unconfined compressive strength and volume shrinkage property of the specimens to determine the optimum cement and fibers dosage.From the microstructural characteristics of the specimens,we analyzed the fibers mechanism on the strength and shrinkage distortion of cement solidified soil.The results show that the addition of fibers can effectively improve the strength and shrinkage of the cement soil.The fibers are randomly distributed in the specimen.The presence of fibers can play a“bridge”role,filling the pores of the soil sample together with the hydration products of cement,making the soil particles fully connected,limiting the displacement between the particles,improving the strength of the specimen,inhibiting the shrinkage of the specimens,and improving the overall stability of the soil mass.The research results can provide theoretical and practical references for the effective solidified treatment and efficient utilization of soft soils.
作者
陈慧娥
王仕鑫
牛壮
CHEN Hui’e;WANG Shixin;NIU Zhuang(College of Construction Engineering,Jilin University,Changchun 130026,China)
出处
《工程地质学报》
CSCD
北大核心
2023年第2期432-440,共9页
Journal of Engineering Geology
基金
国家自然科学基金(资助号:41472242)。
关键词
软土
水泥固化
玄武岩纤维
收缩特征
无侧限抗压强度
Soft soil
Cement solidification
Basalt fiber
Shrinkage characteristics
Unconfined compression strength
