Development of a Practical Tool to Consider Climate and Climate Change in Subgrade Resilient Modulus for Road Pavements

Abstract The prediction of the resilient modulus of foundation soil or subgrade for road pavements has been a subject of significant interest in recent years. This study presents a summary of the factors that influence resilient modulus performance, including climate and climate change, and how this property is fundamental for pavement design. To incorporate climate and climate change in the resilient modulus of the pavement subgrade, a practical tool was developed based on the Climate Information System for Road Design (SICliC) and the Enhanced Integrated Climate Model (EICM) of Mechanistic-Empirical Pavement Design Guide (MEPDG), where the Thornthwaite Moisture Index (TMI) can be estimated based on historical monthly precipitation and mean temperature data and using climate change scenarios for Mexico. The proposal determines the prediction of the behavior of variables that influence the subgrade resilient modulus for unbound granular materials (UGMs) which are associated with climate, such as moisture content, soil suction and degree of saturation, by means of which an environmental factor for unbound materials can be estimated. This factor adjusts the “Resilient modulus at optimum” to an “Resilient modulus at equilibrium” for the project site. Incorporating the climate and climate change of the project site into pavement design, particularly into the resilient modulus of the subgrade, will increase the durability and resilience of pavements.