玄武岩纤维提升水泥土抗拉性能的试验研究

为研究玄武岩纤维对水泥土抗拉力学性能的影响，选取不同长度、直径及掺量的玄武岩纤维掺入水泥土，通过开展单轴拉伸试验、无侧限抗压强度试验和扫描电镜试验，并采用正交试验极差法，分析了玄武岩纤维对水泥土的应力-应变曲线、抗拉强度、拉压强度比和破坏形态的影响规律和微观作用机理。结果表明:玄武岩纤维水泥土的单轴抗拉试验应力-应变曲线可分为弹性变形、破坏、残余强度和稳定4个阶段；纤维变量对抗拉性能影响大小依次顺序为长度、掺量、直径；玄武岩纤维长度9 mm和掺量1.5%为玄武岩纤维的最优单掺参数。玄武岩纤维水泥土的拉压比较未掺入纤维的水泥土的拉压比高，但纤维种类和掺量等对纤维水泥土的拉压比影响较大；三维随机网状分布的玄武岩纤维可提升水泥土的抗拉强度和韧性。

Experimental study on tensile properties enhancement of cement-treated soil by basalt fiber

To investigate the effect of basalt fibers on the tensile properties of cement soil, basalt fibers of different lengths, diameters and doping amounts were selected and incorporated into the cement soil by conducting uniaxial tensile tests, unconfined compressive tests and scanning electron microscopy tests with orthogonal test polarization method. The laws and microscopic mechanisms of the effects of basalt fibers on the stress-strain curve, tensile strength, tensile-compressive strength ratio and damage morphology of the cement soil were analyzed. The results show that: the stress-strain curve of basalt fiber cement soil in uniaxial tensile test can be divided into four stages: elastic deformation, damage, residual strength and stability; in the test, the order of the effect of fiber variables on tensile properties is: length, doping amount and diameter; the basalt fiber with a length of 9 mm and a doping amount of 1.5% is the optimal single doping parameter of basalt fiber. The tensile compression ratio of basalt fiber cement soil is higher than that of unmixed fiber cement soil, but the fiber type and doping amount, etc. have a greater effect on the tensile compression ratio of fiber cement soil; the three-dimensional random mesh distribution of basalt fiber provides reinforcement in the uniaxial tensile stress state of cement soil, which in turn improves the tensile strength and toughness of cement soil.