Experimental study and numerical modelling of post-tensioning systems on the transverse direction of composite steel deck-concrete structures

This study introduces the first investigation into the impact of post-tensioning layouts on the specific transverse direction of steel-deck concrete structures due to the significant limitations of current practice. The experimental work investigates the flexural capacity, structural failures, and crack characteristics of post-tensioned composite (PTC) systems using different tendon profiles and anchorage positions. Three specimens were tested under the four-point bending tests, in which one specimen employed a straight tendon and the remaining two used a profiled tendon (parabolic) with different anchorage positions. The specimens failed due to flexural failure with heavy crushing of concrete and without any damage to the steel sheeting. As compared to conventional concrete structures, the testing revealed a unique crack pattern in the composite system, with cracks initiating 90 degrees at the top edge of the ribs instead of the bottom face of the concrete. The load capacity of specimens using profiled tendon was higher by 15.2 % in the service stage and 17.3 % in the ultimate stage than that of straight tendon. The anchorage positioned at the mid-depth of the section brings the most effective placement to the PTC specimens, where the stress losses can be reduced by 2 % to 4 % and the bending stiffness increased by 4 %. The proposed finite element (FE) models of the PTC specimens were developed and validated against experimental results, ensuring the use of modelling techniques available in the software package ABAQUS.