水泥-固废基固化膨胀土路基填料路用性能研究

Study on Pavement Performance of Cement-Solid Waste-based Solidified Expansive Soil Subgrade Fillers

摘要:

针对因膨胀土强烈胀缩性引发的路基不均匀沉降、路面开裂等工程病害，以及传统水泥固化剂能耗高、工业固废资源化途径匮乏等问题，提出赤泥、粉煤灰、脱硫石膏工业固废协同水泥固化膨胀土的处治方案。通过击实试验确定了固化膨胀土的最佳含水率与最大干密度，并通过无侧限抗压强度试验，系统分析了压实度、固化剂掺量及龄期对固化土强度的影响；同时通过水稳定性试验和冻融循环试验，分别对固化土的水稳定性与抗冻融能力进行了分析。结果表明，随着固化剂用量增加，固化膨胀土试件最大干密度变大、水稳系数提高。在固化剂掺量不变的情况下，随着压实度增加，无侧限抗压强度也随之增大。在压实度不变的情况下，随着固化剂掺量增加，其无侧限抗压强度也随之增大。随着龄期的增加，固化土的无侧限抗压强度明显增大。

Abstract:

To address the engineering issues such as subgrade differential settlement and pavement cracking caused by the significant swelling and shrinkage characteristics of expansive soil, as well as the problems such as high energy consumption of traditional cement stabilizers and the lack of resource utilization channels for industrial solid waste, a treatment scheme for industrial solid wastes such as red mud, fly ash and desulfurization gypsum in combination with cement-solidified expansive soil is proposed. The compaction tests are conducted to determine the optimum moisture content and the maximum dry density of the solidified expansive soil. The unconfined compressive strength tests are performed to systematically analyze the effects of compaction degree, stabilizer content and curing age on the strength of the solidified soil. The water stability tests and the freeze-thaw cycle tests are carried out to analyze the water stability and freeze thawing resistance of solidified soil respectively. The results indicate that with an increase of stabilizer content, the maximum dry density of solidified expansive soil specimens increases and the water stability coefficient of the specimens improves. When the stabilizer content remains constant, the unconfined compressive strength increases with an increase of compaction degree. Under a constant compaction degree, the unconfined compressive strength also increases with an increase of stabilizer content. Furthermore, the unconfined compressive strength of the solidified soil obviously increases with the curing age increasing.