AASHTO T 307-99 (2017) PDF Download

The AASHTO T 307-99 (2017) standard specifies the methods for determining the resilient modulus of soils and aggregate materials. The resilient modulus is a measure of the elastic modulus of untreated base and subbase materials and subgrade soils, considering certain nonlinear characteristics. This standard applies to both undisturbed and disturbed samples of natural and compacted subgrade soils, as well as untreated base and subbase materials prepared through laboratory compaction.

The testing procedures outlined in this standard simulate the physical conditions and stress states that materials experience beneath flexible pavements under moving wheel loads. The stress levels used for testing depend on the location of the specimen within the pavement structure. Samples from the base and subbase are subjected to different stress levels compared to those from the subgrade. The size of the specimen for testing is determined based on the material's type, gradation, and plastic limit.

The resilient modulus values obtained from this standard can be used in structural response analysis models to calculate the pavement's structural response to wheel loads. They can also be utilized in pavement design procedures for designing pavement structures.