Experimental and Numerical Investigation of the Tendon Layout Effect on Flexural Capacity in Post-Tensioning Beams

Abstract

This study examined the bending and ductility capacities of reinforced concrete beams produced with the post-tensioning technique used to cross wide spans in structures. For this purpose, six beam specimens were produced. Two of these specimens (NB/1-2) were made of normal reinforced concrete and the other four were created by applying the post-tensioning technique. The steel post-tensioning tendons of two of these specimens (POSTTENST/1-2) were placed straight along the beam, and the other beam specimens (POSTTENP/1-2) were placed parabolically. Four-point bending tests were carried out on beam specimens. As a result of the experiments, it was determined that beams strengthened with straight and parabolic steel tendons could carry approximately 62% more load and behave approximately 65% more ductile than unstrengthened beams. In the study, finite element models of the beam specimens were created and analyzed using the Abaqus program. In the parametric analysis, it was determined that as the ratio of the beam specimen free span to the beam section height decreases, the shear stresses occurring in the beam section having parabolic tendons are lower than those of beams with straight tendons. This finding provides guidance to structural engineers in the preliminary design of structural systems.

Keywords

• finite element
• flexural capacity
• post-tensioning
• tendon layout