Title: RC Columns Subjected to Reinforcement Corrosion under Sustained Load

Author(s): Beatriz Martín-Pérez, Samer Jabbour and Arnaud Vadeboncoeur

Publication: Web Session

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Date: 3/24/2019

Abstract:
This paper presents the results of an experimental study wherein ten circular spirally-reinforced concrete columns were subjected to accelerated corrosion while sustaining a constant service compressive load. Two types of column design, with five specimens of each type, were used in the experimental program: type CV, with a spiral reinforcement spacing of 220 mm, and type CS, with a spiral reinforcement spacing of 80 mm. In type CV specimens, the vertical reinforcement was corroded and isolated from non-confining spiral reinforcement, whereas in type CS specimens, the spiral reinforcement was corroded and isolated from the vertical reinforcement to study the effect of confinement. The cracking initiation, pattern, and widening of the concrete cover were monitored for a period of 4-10 months, and relations obtained between the crack widening and propagation and the elastic shortening of the column and steel mass loss were established. The cracking pattern was found to be wider and in the form of longitudinal cracks along the vertical bars in type CV columns, but more random and distributed over the surface and not as wide in type CS columns. After the accelerated corrosion period, eight columns were tested to failure under either concentric or eccentric load; the vertical deformation, cracking pattern and failure type were monitored and recorded. The failure of type CV specimens was characterized by sudden crushing of the concrete and longitudinal reinforcement buckling, with a reduction in load capacity of 30-40%. Columns of type CS failed in a ductile manner by progressive spalling of the concrete cover, maintaining their load capacity in spite of the corroded confinement reinforcement.