【摘要】 目的 为解决工业固体废弃物排放污染环境以及粉质砂土性能较差难以填充路基的问题，利用工业固体废弃物矿渣，电石渣和绿色友好材料MgO固化粉质砂土，以期达到以废治废的目的。方法 通过开展固化粉质砂土的无侧限抗压、X射线衍射(XRD)、电镜扫描(SEM)等试验，研究了固化剂配合比、养护龄期等复杂因素对粉质砂土固化效能影响及微观机理分析。结果 试验研究表明，在对含水率为40%的粉质砂土固化的正交试验中，影响固化粉质砂土7d和56d无侧限抗压强度因素的主次关系为矿渣>MgO>电石渣，而影响14d和28d无侧限抗压强度因素的主次关系变为矿渣>电石渣>MgO。矿渣对试块强度的影响最大，在养护龄期7d、14d和56d时影响显著，得出该固化剂的最佳配比为15%矿渣+7%电石渣+8%MgO。不同养护龄期的固化粉质砂土的峰值应力对应的破坏应变为0.9%～1.9%,且大致随峰值应力的增加而降低。微观结构分析表明，固化剂反应产生的水化硅酸钙(C-S-H)和水化硅酸镁(M-S-H)是主要胶凝产物，它们填充孔隙并与颗粒形成键结，促进了强度的发展。结论 研究成果可为绿色、低碳矿渣-电石渣-MgO胶凝材料研发及其在粉质砂土固化等土体加固领域中应用提供理论支撑。更多还原

【Abstract】 Objective To address environmental pollution from industrial waste and improve silty sand for subgrade filling, slag, calcium carbide slag and MgO were employed to solidify silty sand.Methods Unconfined strength(UCS),X-ray diffraction(XRD),and electron microscope scanning(SEM) tests were carried out to evaluate the effects of curing agent ratios and curing ages on soil strength and microstructure.Results The Orthogonal tests on 40% moisture-content silty sand showed that slag dominated UCS at 7d and 56d(slag > MgO > calcium carbide slag),while calcium carbide slag surpassed MgO at 14d and 28d(slag > calcium carbide slag>MgO).The optimal ratio was 15% slag+7% calcium carbide slag+8% MgO.The greatest effect of slag on the strength of the specimen was found at 7d, 14d and 56d.The optimum ratio of the curing agent was 15% slag + 7% calcium carbide slag + 8% MgO.Peak stress failure strains ranged from 0.9% to 1.9%,inversely related to peak stress.Microstructural analysis showed that hydration products(C-S-H and M-S-H) filled pores and bonded particles, enhancing strength.Conclusion The research supports green, low-carbon slag-calcium carbide slag-MgO binders for soil stabilization.更多还原