Geotechnical structures made of granular material tend to be unsaturated during their service life. However, there is presently a lack of sufficient research and studies on their volumetric behavior under unsaturated conditions. In this study, loading and wetting induced volumetric behavior of granular materials in the unsaturated state was studied within a moisture content-based framework. Recycled crushed brick (CB) and excavation waste rock (WR) were the granular materials used in this research to promote sustainable construction. Several loading, unloading, and wetting state paths were investigated with respect to virgin compaction surfaces (VCS) developed using groups of compaction curves. The obtained experimental data was utilized to develop a constitutive model capable of predicting wetting-induced volume changes of granular materials in a net stress range of 100–4000 kPa and gravimetric moisture content range of 3.6% for WR, and 7.5% for CB to saturation. The model was verified by undertaking several independent state paths on independent materials and comparing the experimental responses with those predicted using the model. The proposed model is featured with simplicity in acquiring the model input parameters with the aim of filling the existing gap between the theoretical and real-life application of unsaturated soil mechanics. An application of the model can be the basis for the prediction of the settlement of a granular geotechnical structure that is being externally loaded and is subject to changes in moisture content due to climatic effects.

由颗粒材料制成的岩土结构在其使用寿命期间往往是不饱和的。然而，目前对其在非饱和条件下的体积行为缺乏足够的研究和研究。在这项研究中，在基于水分含量的框架内研究了不饱和状态下颗粒材料的加载和润湿引起的体积行为。再生碎砖 (CB) 和开挖废石 (WR) 是本研究中用于促进可持续建筑的颗粒材料。针对使用压实曲线组开发的原始压实表面 (VCS)，研究了几种加载、卸载和润湿状态路径。获得的实验数据用于开发本构模型，该模型能够预测颗粒材料在 100-4000 kPa 的净应力范围和 3.6% 的重量含水量范围内颗粒材料的润湿引起的体积变化，以及 7.5% 的 CB 到饱和. 该模型通过在独立材料上进行几个独立的状态路径并将实验响应与使用模型预测的响应进行比较来验证。所提出的模型具有获取模型输入参数简单的特点，旨在填补非饱和土力学理论与实际应用之间的现有差距。