Novel method for identifying residual prestress force in simply supported concrete girder-bridges
Journal
Advances in Structural Engineering
Journal Volume
24
Journal Issue
14
Pages
3238-3251
Date Issued
2021
Author(s)
Abstract
Testing methods are required for estimating prestress losses in Prestressed Concrete (PC) girder-bridges. They mainly include destructive approaches which cause significant damages. Conversely, dynamic nondestructive methods are unsuitable. Given these findings, a novel method for identifying residual prestress force in simply supported PC girder-bridges was implemented. Following the vertical load application in a three-point bending, the method estimates the prestress force by measuring the vertical deflection at a quarter or, alternatively, at the midspan of the PC girder-bridge. The method also requires information regarding its flexural rigidity. Particularly, the initial tangent Young’s modulus must be evaluated by compression tests on cores drilled at its quarter and midspan cross-sections after three-point bending. In absence of the geometric and/or material properties, the flexural rigidity can be estimated according to free vibrations. Secondly, the method comprises a reference solution, or a finite element model of the PC girder-bridge, in which the prestress force is unknown. Thirdly, the measured deflection becomes a parameter of the prestress force identification process. Accurate identifications are obtained when the deflection, under a higher vertical load, was precisely measured and the flexural rigidity was determined using reference solution and initial tangent Young’s modulus. In this article, the novel method was simulated on a simply supported PC beam-bridge subjected to time-dependent prestress losses for ?9.5 months in the laboratory. ? The Author(s) 2021.
Subjects
Concrete beam-bridge
flexural rigidity
prestress force identification
three-point bending
vertical deflection
Bending dies
Bending tests
Compression testing
Prestressed beams and girders
Prestressed concrete
Rigidity
Flexural rigidities
Nondestructive methods
Prestress forces
Reference solution
Residual prestress
Simply supported
Three point bending
Vertical deflections
Concrete beams and girders
SDGs
Type
journal article