我国钢铁产量位居世界第一，钢厂在炼钢过程中会产生大量钢渣，但现阶段钢渣利用率不足30%。若将钢渣应用于水泥稳定类基层，不仅能有效提高废弃钢渣的利用率，还将降低土地占用，减少石料开采，具有良好的经济和环境效益。本文以包钢钢厂的大粒径钢渣在半刚性基层中应用为研究对象，综合理论分析、室内试验、数值模拟等技术手段，研究了静压成型和振动成型对半刚性大粒径钢渣基层性能的影响，分析了不同半刚性大粒径钢渣基层施工厚度对路面结构的力学影响，以推动大粒径钢渣在半刚性基层中的应用。主要研究内容如下：

首先对钢渣进行物理化学性质、浸水膨胀率等试验，验证了大粒径钢渣在水泥稳定碎石基层中的可行性；采用大粒径沥青混合料级配设计方法，调整不同掺配比例的钢渣，设计了悬浮密实和骨架密实两种结构类型的水泥稳定大粒径钢渣混合料，分析不同水泥掺量和成型方式对混合料最佳含水率和最大干密度的变化规律。同一结构类型下，振动成型混合料的最大干密度更高，最佳含水量更低。同一成型方式下，骨架密实结构混合料的最大干密度更高，最佳含水率更低。

其次，对不同成型方式和结构类型的水泥稳定大粒径钢渣混合料进行无侧限抗压强度、间接抗拉强度、抗压回弹模量等测试，研究其力学特性与养生龄期、水泥掺量、成型方式、结构类型的规律，并基于X射线衍射试验和扫描电镜试验分析混合料的强度形成机理。此外，对优选的4种混合料进行干缩和温缩试验，研究成型方式、结构类型对混合料收缩性能的影响，表明了养生龄期和水泥掺量的增加能提高混合料的力学性能，振动成型混合料的力学性能优于同条件下的静压成型混合料，悬浮密实结构混合料力学性能优于骨架密实结构混合料。对于悬浮密实结构，振动成型混合料的7d无侧限抗压强度、28d间接抗拉强度、90d抗压回弹模量比静压成型混合料高109.9%、122.8%、54.2%；对于骨架密实结构，则相应高108.5%、117.4%、52.9%。振动成型法可降低两种结构类型混合料的收缩系数，骨架密实结构混合料的干缩系数小于悬浮密实结构混合料，但温缩系数更大。振动成型较静压成型的悬浮密实和骨架密实结构混合料干缩系数分别可降低10.4%、10.2%，温缩系数可降低5.4%、5.6%。

最后，通过沥青路面水泥稳定大粒径钢渣基层典型结构的构建，研究不同施工工法、施工季节对路面结构的影响。探讨荷载-温度耦合作用下路面结构的Mises应力、路表弯沉、剪应力和层底拉应力等变化规律，对比工法和季节对各因素的影响程度，揭示了基层施工厚度的增大可有效降低路面结构的Mises应力、路表弯沉、最大剪应力和基层层底拉应力的趋势。此外，不同施工工法对基层、底基层应力的影响程度大于面层，施工工法对路面弯沉值比季节影响更大。

China's steel production ranks first in the world, and steel mills produce a large amount of steel slag during the steelmaking process. However, the utilization rate of steel slag is less than 30% at present. If steel slag is applied to cement-stabilized base layers, it will not only effectively increase the utilization rate of waste steel slag but also reduce land occupation and decrease stone exploitation. It can also usher in a period of significant economic and environmental benefits. This study focuses on the application of large-sized steel slag produced by Baotou Steel in semi-rigid base. Through comprehensive theoretical analysis, indoor experiments, numerical simulation and other technical means, this study explores the effects of quasi-static forming and vibration forming on the performance of steel slag base. The mechanical effects of different construction thicknesses of semi-rigid large-sized steel slag base on pavement structure were analyzed to promote the application of large-sized steel slag in semi-rigid base. The main contents are as follows:

Initially, the physical and chemical properties, chemical analysis and immersion expansion rate of steel slag were conducted to verify the feasibility of large-sized steel slag in cement stabilized macadam base. The gradation design method of large stone asphalt mixtures was adopted to mix different proportions of steel slag and macadam. Two structure types of cement stabilized large-sized steel slag (CSLS) mixtures with suspended-dense and skeleton-dense structures were designed. The potential law of the optimal moisture content and the maximum dry density of the mixture under different cement contents and forming methods were analyzed. For the same structure type, vibration forming mixtures can get higher MDD and lower OMC, while for the same forming type, skeleton-dense structures can get higher MDD and lower OMC.

Secondly, unconfined compressive strength, indirect tensile strength, compressive resilience modulus tests of CSLS mixtures with different forming methods and structure types were conducted. The potential laws of its mechanical properties, curing time, cement contents, forming methods and structure types were studied. The strength formation mechanisms of the mixtures were analyzed based on X-ray diffraction and scanning electron microscope tests. Afterwards, drying shrinkage and temperature shrinkage tests were conducted on the optimal four selected mixtures. The effects of forming methods and structure types on the shrinkage performance of CSLS mixtures were studied. The results show that curing time and cement contents have a positive impact on the mechanical properties of the mixtures. The mechanical properties of the vibration forming mixtures are better than those of the quasi-static forming mixtures under the same conditions. The mechanical properties of suspended-dense structure mixtures are superior to that of skeleton-dense structures. For suspended-dense structures, the 7d unconfined compressive strength, 28d indirect tensile strength, and 90d compressive resilience modulus of vibration forming mixtures are 109.9%, 122.8%, and 54.2% higher than those of quasi-static forming mixtures. For skeleton-dense structures, the corresponding ratio are 108.5%, 117.4%, and 52.9%. The vibration forming method can reduce the shrinkage coefficient of two structure types of CSLS mixtures. The dry shrinkage coefficients of the skeleton-dense structures are lower than those of suspended-dense structure mixtures, but the temperature shrinkage coefficients are higher than those of suspended-dense structure mixtures. Compared with quasi-static forming method, vibration forming method can reduce the dry shrinkage coefficient by 10.4% and 10.2%, respectively, and the temperature shrinkage coefficient can be reduced by 5.4% and 5.6%.

Finally, the influence of different construction methods and construction seasons on the road structure were studied by establishing a typical structure of CSLS base structure of asphalt pavement. The change trend of Mises stress, surface deflection, shear stress and layer bottom tensile stress of pavement structure under coupling of temperature and load were discussed. At the same time, the influence of different construction methods and seasons on various factors were compared. The results show that the increasing construction thickness of the base layer can effectively reduce the Mises stress, pavement deflection, maximum shear stress, and tensile stress at the bottom of the base layer. Different construction methods have a greater impact on the stress of the base and sub-base than the pavement, and construction methods have a greater impact on the deflection value of the pavement than construction seasons.