水泥-纤维固化风积砂劈裂特性跨尺度研究

Cross-scale Study on Splitting Characteristics of Cement-fiber Solidified Aeolian Sand

目的 研究水泥掺量、纤维掺量和纤维长度对固化风积砂劈裂强度的影响规律,揭示添加剂掺量,纤维赋存形态及长度对水泥-纤维固化风积砂劈裂强度的影响机理。方法 将水泥、玻璃纤维作为添加剂掺入风积砂中,采用劈裂试验测定试样的劈裂强度,采用CT断层扫描技术,获取水泥-纤维固化风积砂不同层位平扫切片,并借助Avizo图像处理软件对CT平扫切片进行内部形态三维重构。结果 在掺量为0.3%的6 mm纤维及水泥掺量10%的组合条件下,试样劈裂强度达到最大值;当纤维掺量控制在0.3%时,纤维可均匀地赋存在试件内部,形成交错网状的三维结构;采用CT三维重构方法从细观证实了当纤维在试样内部达到理想赋存形态时,纤维对水泥-纤维固化风积砂的劈裂强度起到增益效果。结论 掺入适量的水泥和纤维可改善风积砂的工程力学特性,研究成果可为水泥-纤维固化风积砂路基病害防治提供科学依据。

The influence of cement content, fiber content and fiber length on the splitting strength of solidified aeolian sand was studied.The influence mechanism of additive content, fiber occurrence form and length on the splitting strength of cement-fiber solidified aeolian sand was revealed.Cement and glass fiber were added into aeolian sand as additives, and the splitting strength of the sample was measured by splitting test.The plain CT slices of different layers of cement-fiber solidified aeolian sand were obtained by CT scanning technology, and the 3D reconstruction of internal morphology of plain CT slices was carried out by Avizo image processing software.Under the combination of6mm glass fiber content of 0.3 % and 10 % cement content, the splitting strength of the sample reaches the maximum;When the fiber content is controlled at 0.3 %,the fiber can be evenly distributed within the specimen, forming a three-dimensional staggered network structure;The CT three-dimensional reconstruction method was used to confirm that when the fiber reaches the ideal occurrence form in the sample, The fiber has a gain effect on the splitting strength of cement-fiber solidified aeolian sand.Appropriate amount of cement and fiber can improve the engineering mechanical properties of aeolian sand;The research results can provide scientific basis for disease prevention and control of cement-fiber solidified aeolian sand subgrade.