Analysis of Airfield Concrete Block Pavement Behavior Using PLT and CBR tests

Concrete pavement is been used in the aprons owing to its resistance to static loads as the main loads of aircraft. An alternative is to use interlocking concrete block pavement with advantages such as simple execution and repair and with no needs for curing. There is concern about the effect of the CBR of the subgrade on the resistance of block pavers to permanent deformation. The present study conducted to investigate the effect of subgrade (CBR) on these pavements in the apron. The Plate Load Test (PLT) performed on a 2m×2m prototype constructed as per Federal Aviation Administration (FAA) regulations. The layers of this 3D model include compacted subgrade, sub-base, crushed aggregate base and Cement-Treated Base (CTB) and 8-cm thick concrete blocks. Sensitivity analysis showed a reduction of over 12% in vertical deflection with increasing CBR from 2 to 10 and a reduction of below 4% in the presence of subgrade even with CBR=10~20%. Using subgrade with CBR of over 10 has found insignificantly increase the resistance of block pavements to permanent deformation. Concern about the risk of permanent deformation is obliterated given the key role of the Cement-Treated Base in redistributing the loads.