Physical performance of flexible pavement system with and without a Portland-cement-concrete (PCC) slab for geofoam embankments

Pavement system design for geofoam block embankments requires special solution due to their low California Bearing Ratio (CBR) values. Hence, the use of a reinforced Portland-cement-concrete (PCC) slab atop the geofoam block assemblage is considered as a practical approach to increase the stiffness of the pavement. On the other hand, the PCC slab has some inherent disadvantages such as construction delay due to curing. A thicker pavement system without a PCC slab can be a potential alternative. Hence, the performance of flexible pavement systems with and without PCC slab were investigated using the accelerated pavement test (APT) program in detail. Two 3.75 m-wide and 10 m-long pavements were constructed in a test bed, and a controlled wheel load was applied using a 3-axle, 37.72-ton truck that traveled with an average speed of 16.5 km/h. The test was terminated, when rutting reached to steady deformation pattern at 1299 passes (3897 axle repetitions), which is equal to 20,264.4 equivalent single axle loads (ESAL). The test program also included plate load tests (PLT) and falling weight deflectometer (FWD) tests. The full-scale APT results showed that flexible pavement systems without a PCC slab for geofoam block embankments can be a viable option.