Parametric Study of Saw-Cut Method

Knowledge of the level of residual prestressing is a crucial basis for determining the load-carrying capacity of prestressed concrete structures. The value of prestressing force decreases over time because of expected but sometimes also unexpected factors. Expected factors include prestress losses according to available standards. On the other hand, prestress losses that are not considered in standards can be attributed to environmental distress or conceptual problems of prestressed concrete structures. In Europe, we are challenging ageing infrastructure. Thus, we need to decide whether old bridges should be replaced, or their structural state facilitates to preserve them in service. The level of prestressing can be evaluated, e.g., using indirect methods for determining the value of residual prestressing force. These methods are based on the measurements of deflection, the width of the crack, or stress (strain) and subsequently, it is possible to determine the actual state of prestressing indirectly using obtained results. This paper introduces the parametric study of Saw-cut method which is generally considered as a non-destructive indirect method. A presented study is performed for the determination of factors that could influence the application of Saw-cut methods in practice. The studied factors include the value of prestressing force, depth and axial distance of saw-cuts, and FE mesh. For numerical analysis, a 2D finite element model with the assumption of nonlinear material behavior is performed in ATENA 2D Software. Finally, the conclusions of the parametric study are discussed and summarized.