Anchorage capacity of naturally corroded reinforcement in an existing bridge
Paper i proceeding, 2012

Corrosion of reinforcement is one of the most common causes of deterioration in reinforced concrete bridges. Anchorage, prior to shear and bending moment resistance, is the main uncertainties in the evaluation of the structural behavior of corroded reinforced concrete bridges. Thus, to assess the remaining load-bearing capacity of deteriorated existing bridges, models to estimate the remaining bond and anchorage capacity are needed. Most of our knowledge on the structural behavior of corroded reinforced concrete structures is based on experimental investigations of artificially corroded concrete specimens. In this study, the anchorage capacity of naturally corroded steel reinforcement was investigated experimentally. The test specimens were taken from edge beams of a bridge, Stallbackabron, in Sweden. Since the dimensions and the amount of reinforcement were given on beforehand, it was only the test set-up which could be chosen freely. A test set-up consisting of a four point bending test indirectly supported with suspension hanger was considered to be the best alternative with the least disturbance and influence of the natural damages. Detailed design was done by using a non-linear finite element method. It was seen that the edge beams needed to be strengthened with transverse reiforcement, else they would have failed in a local failure at the suspension hole or in shear. The technique adopted for the strengthening was an internal mounting of steel reinforcement using epoxy as adhesive. The bond and anchorage behavior was examined in tests through measurements of applied load, free-end slip and mid-span deflection. A first test showed that additional measures were needed to ensure anchorage of the strengthening bars. In subsequent tests, they were therefore anchored at the top of the beam with hexagonal nuts and flat steel plates. In two following tests, the beams failed in a splitting induced pull-out failure, i.e. anchorage failure was achieved as wanted.

Four-point bending test

Railroad bridges

Mid-span deflection

Corroded reinforcement

Bending moment resistance

Reinforced concrete

Concrete construction

Nonlinear finite element method

Corrosion of reinforcement

Strengthening (metal)

Concrete specimens

Anchorages (foundations)


Pull-out failure

Steel plates


Steel reinforcements

Structural behaviors

Experimental investigations

Load-bearing capacity

Finite element method

Test specimens

Existing bridge

Applied loads

Detailed design


Local failure


F. Berg

D. Johansson

Karin Lundgren

Chalmers, Bygg- och miljöteknik, Konstruktionsteknik

Mario Plos

Chalmers, Bygg- och miljöteknik, Konstruktionsteknik

Proceedings of the Sixth International Conference on Bridge Maintenance, Safety and Management, IABMAS 2012, Stresa, Lake Maggiore, 8-12 July 2012



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