The influence of prestress level on the behavior of prefabricated precast concrete bridge deck panel systems with different overlay thicknesses

The bond properties and the excellent performance of the applied protecting overlay in segmental bridge deck panels are essential to ensure the overall quality of the bridge system. This research investigates the role of deck panels overlaying in a prefabricated fully-depth precast bridge using the NLFEA simulation approach under various overlaying thicknesses and prestressing levels. Using the NLFEA approach helps reduce the required time, save cost, study the effect of more factors, and demonstrate any behavior at a given load value at a given position in the investigated system. The NLFEA simulation was firstly validated against a published experimental work, and then it was extended into thirty-two prefabricated full-depth bridge systems composed of precast panels under various prestressing levels. The studied prestressing levels were related to the minimum and maximum prestressing levels as follows; (1.38 MPa (aP, Min), 2.76 MPa (2aP, Min), 4.14 MPa (3aP, Min), and 5.52 MPa (aP, max = 4aP, Min)). In addition, the effect of overlaying thickness on the original bridge thickness was also studied (to/ts) of 0.00 (Without), 0.06, 0.12, 0.18, 0.24, 0.30, 0.36, and 0.42). It has been highlighted that concrete overlying has a significant role in improving the system's overall behavior due to its good bonding with the deck panel, including the stiffness, toughness, cracking load, ultimate strength, and ultimate deflection. In addition, the produced stress by the AASHTO HS20 truck is less than the bond strength at the overlying interface. The maximum and minimum practical values for the overlaying thickness were proposed under different pre-stressing levels, aiding in getting the guidance of mitigating the detachment problem under the effect of the AASHTO HS20 truck and impact loading.