掺钢渣土强度的干湿循环劣化效应及机理研究

发布时间：2018-10-11 17:57

【摘要】：以掺钢渣土为主要研究对象,采用"透水石上吸水-自然风干"方法模拟路床材料的干湿循环状态,研究了掺钢渣土强度的干湿循环劣化性能,从强度破坏模式与微观机理分析石灰对钢渣活性激发的影响。结果表明:随着干湿循环次数的增加,试件含水率呈增大趋势并趋于稳定,变化幅度在3%以内。掺钢渣土无侧限抗压强度与劈裂强度的干湿循环劣化效果明显,其中石灰土的衰减幅度最大,分别为59.5%与55.3%,石灰钢渣土最小。劈裂抗拉强度与无侧限抗压强度比值结果发现,石灰土与石灰钢渣土随干湿循环次数变化,该比值f_t/f_(cu)基本稳定,在12.3~19.4之间,但钢渣土f_t/f_(cu)均小于12.8;钢渣土劈裂抗拉强度衰减幅度显著高于无侧限抗压强度,劈裂抗拉强度更能反映钢渣土的干湿循环劣化性能。干湿循环后掺钢渣土试件抗压强度与试件核心区的干湿循环劣化程度密切相关,而劈裂强度则更多的反映试件外围部分的强度特征。对比钢渣土与石灰钢渣土强度形成机理,验证钢渣在碱性环境中更易形成强度大的沸石类矿物。在工程应用中,建议掺入适量石灰。
[Abstract]:Taking steel-doped residue as the main research object, the dry and wet cycle state of the road bed material was simulated by the method of "absorbing-natural air drying on permeable stone", and the dry and wet cycle deterioration performance of the strength of the steel-doped residual soil was studied. The influence of lime on the activation of steel slag was analyzed from the strength failure mode and microscopic mechanism. The results showed that the moisture content of the specimens increased with the increase of the times of dry and wet cycles and tended to be stable, and the range of change was less than 3%. The effect of dry and wet cycle degradation of unconfined compressive strength and splitting strength of steel-doped residual soil is obvious, among which the attenuation range of lime soil is the largest, which is 59.5% and 55.3%, respectively, and the lime steel residue is the smallest. The ratio of splitting tensile strength to unconfined compressive strength shows that the ratio of lime soil to lime steel residue varies with the times of dry and wet cycles, and the ratio of f T / f _ (cu) is basically stable, ranging from 12.3 to 19.4. However, flife / f _ (cu) of steel residue is less than 12.8.The attenuation range of splitting tensile strength of steel residue is significantly higher than that of unconfined compressive strength, and the splitting tensile strength can better reflect the dry and wet cycle deterioration of steel slag soil. The compressive strength of the specimens doped with steel residue after dry and wet cycling is closely related to the dry and wet cycle deterioration of the core of the specimens, while the splitting strength reflects the strength characteristics of the peripheral parts of the specimens. Comparing the strength formation mechanism between steel residue and lime steel residue, it is proved that steel slag is more likely to form zeolite minerals with high strength in alkaline environment. In engineering application, it is suggested that appropriate amount of lime be added.
【作者单位】：中原工学院建筑工程学院;郑州大学水利与环境学院;
【基金】：国家自然科学基金青年基金,项目编号51509274 河南省高等学校重点科研项目,项目编号15A560013
【分类号】：U414

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