Thermal Conditioning to Improve Geotechnical Properties of Recycled Asphalt Pavements

A procedure for thermal conditioning was introduced to accelerate the compression and improve geotechnical properties of recycled asphalt pavements (RAP) including resilient modulus, compressibility, shear strength, and creep response. Temperature-controlled resilient modulus, one-dimensional compression, and triaxial compression tests were conducted to evaluate the use of RAP as base course or embankment fill. For base course application, increasing temperature increased the plastic strain and reduced the resilient modulus of the RAP specimens that were compacted at room temperature. However, when the specimens were compacted at elevated temperatures and tested at room temperature, significant reduction in plastic strain and increase in resilient modulus were attained. For embankment fill applications, compaction and compression at elevated temperatures increased the shear strength and reduced the compressibility and creep strain of the RAP specimens tested at room temperature. Compaction and compression of the RAP specimens at elevated temperatures induced thermal conditioning and improved geotechnical properties. To improve performance of structural fills containing RAP, construction is recommended during warmest months of the year.