The strength of lime-cemented soils has received significant attention in previous studies. However, limited research has focused on studying soil mixtures for extended durations beyond 365 days, which is essential for understanding shear strength, microstructure, unconfined compressive, and matric suction. Consequently, there is a need to explore the long-term behavior and unsaturated properties of soil specimens cured for up to 500 days using appropriately hydrated lime, considering the semi-empirical porosity/lime index. By investigating various curing times ranging from 15 to 500 days, as well as employing different compaction energies (standard, intermediate, and modified) and lime content ranging from 3% to 9% by weight, this study aims to characterize the evolution of resistance and unsaturated properties of lime-cemented soils. The semi-empirical porosity/lime index is employed to guide the characterization and analysis of the mixtures' resistance properties. By developing equations to estimate the resistance of these mixtures, the study contributes to reducing lime consumption (and reducing CO2 emissions during its production) and optimizing curing time, leading to environmentally friendly geotechnical projects. Due to the utilization of the porosity/lime ratio, lime consumption can be minimized, and curing time can be fixed, resulting in a significant reduction in energy requirements, which is beneficial for the environment. The outcomes of this research have profound implications for the design and construction of sustainable structures such as dams, pavements, and slope protection systems, ensuring their long-term stability, resilience, and ecological balance.