Gypsum is among the widely used construction materials, and is nowadays been considered for a variety of applications including soil stabilization, foundation works, grouting and brick manufacturing etc. Considering this prevalent utilization of gypsum in construction industry, a comprehensive study was conducted to examine the time-dependent strength and deformation characteristics of Gypsum Mixed Sand (GMS) by examining the hardening characteristics (up to nine months) and loading rate (up to five folds); under unconfined monotonic loading conditions. Effects of different factors including gypsum content, hemihydrate batches and interaction between ageing and loading rate were considered to rationally comprehend the time-dependent mechanical behaviour of GMS. The results revealed an obvious reduction in the peak strength of GMS during the initial month of ageing, and no further effects of ageing were witnessed afterwards. Moreover, a unique and significant dependency of strength and deformation on the loading rate was observed for GMS, and this behaviour was categorized into three different zones of loading rates.

石膏是广泛使用的建筑材料之一，如今已被考虑用于土壤稳定，地基工程，灌浆和砖制造等各种应用。考虑到石膏在建筑业中的广泛使用，进行了全面研究以检查通过检查硬化特性（长达9个月）和加载速率（高达5倍），得出石膏混合砂（GMS）随时间变化的强度和变形特性；在无限制单调加载条件下。认为石膏含量，半水合物批次以及老化和加载速率之间的相互作用等不同因素的影响可以合理地理解GMS随时间变化的力学行为。结果表明，在老化的最初一个月中，GMS的峰值强度明显降低，此后未发现老化的进一步影响。此外，对于GMS，观察到强度和变形对加载速率的独特且显着的依赖性，并且此行为可分为三个不同的加载速率区域。