The elastic or resilient modulus of pavement materials is an important material property in any mechanistically based design/analysis procedure for flexible pavements. Repeated load resilient modulus tests are being performed on all unbound materials and soils of the Specific Pavement Studies (SPS) and General Pavement Studies (GPS) test sections that are in the Federal Highway Administration (FHWA) Long Term Pavement Performance (LTPP) program in accordance with LTPP test protocol P46. Previous studies have shown that the resilient modulus test results can be affected by sampling technique, testing procedure, and errors that can occur during the testing program. Thus, the FHWA sponsored a detailed review of the resilient modulus test results that have a Level E status in the LTPP database, i.e., they have passed all levels of the quality control (QC) checks.


This report documents the first comprehensive review and evaluation of the resilient modulus test data measured on pavement materials and soils recovered from the LTPP test sections. The resilient modulus test data were found generally to be in excellent condition with less than 10 percent of the tests exhibiting potential anomalies or discrepancies in the data.