What is the primary reason for conducting laboratory testing of pavement materials before rehabilitation?

The primary reason for conducting laboratory testing of pavement materials before rehabilitation is to determine the existing pavement's structural capacity and material properties, informing the design of the rehabilitation strategy. Laboratory tests, such as core sampling and testing, provide information on the strength, stiffness, and composition of the existing pavement layers. This information is crucial for determining the appropriate thickness and type of overlay or other rehabilitation treatment. For example, testing may reveal that the existing asphalt layer has deteriorated and lost its structural integrity, requiring a thicker overlay to restore the pavement's load-bearing capacity. Testing can also identify the presence of problematic materials, such as asphalt binder with excessive aging or aggregates that are susceptible to stripping. This information allows engineers to select rehabilitation materials and techniques that are compatible with the existing pavement and will provide long-term performance. Without laboratory testing, the design of the rehabilitation strategy would be based on assumptions about the pavement's condition, which could lead to inadequate or over-designed treatments. Accurate material characterization ensures an effective and economical rehabilitation design.