Experimental study of FRP-strengthened concrete beams with corroded reinforcement
Artikel i vetenskaplig tidskrift, 2021

Corrosion of steel reinforcement is the major cause of deterioration in reinforced concrete structures. Strengthening of concrete structures has been widely studied. However, most research was conducted on sound structures without considering the effects of corrosion. This paper presents an experimental study of the feasibility of using externally bonded FRP laminates combined with U-jackets, applied directly without repairing the deteriorated concrete cover, to strengthen beams with corroded reinforcement. Ten beams were tested in four-point bending. Two beams were not deteriorated and non-strengthened; these served as references. The other eight were pre-loaded to induce flexural cracks and then exposed to accelerated corrosion. Two of the deteriorated beams were not strengthened, three were strengthened with glass-FRP (GFRP) laminates and three with carbon-FRP (CFRP) plates on the beam soffits. On the six strengthened beams, CFRP U-jackets were installed along the span. Local corrosion levels were evaluated with a 3D-scanning technique. Pitting corrosion significantly reduced the load-carrying and deformation capacity of the deteriorated beams. Despite average corrosion levels of 20%, local corrosion levels up to 57% and corrosion-induced cracks up to 1.9 mm wide, the FRP-strengthening method (applied directly to the beams without repairing the deteriorated concrete cover) was effective in upgrading the load-carrying capacity and flexural stiffness. The applied U-jackets effectively suppressed the delamination of the concrete cover and led to the rupture of GFRP laminates and a utilisation ratio of CFRP plates up to 64%. However, improvement in the deformation capacity was not noticeable; this requires further research.

Corrosion-induced cracks

Reinforced concrete

FRP composites

Flexural strengthening

Pitting corrosion

3D scanning

Local corrosion level

Författare

Jincheng Yang

Chalmers, Arkitektur och samhällsbyggnadsteknik, Konstruktionsteknik

Reza Haghani Dogaheh

Chalmers, Arkitektur och samhällsbyggnadsteknik, Konstruktionsteknik

Thomas Blanksvärd

Luleå tekniska universitet

Skanska

Karin Lundgren

Chalmers, Arkitektur och samhällsbyggnadsteknik, Konstruktionsteknik

Construction and Building Materials

0950-0618 (ISSN)

Vol. 301 2021 124076

Reparation och förstärkning av betongkonstruktioner med korroderad armering

Trafikverket (TRV2019/64827), 2019-08-01 -- 2022-09-30.

Styrkeområden

Building Futures (2010-2018)

Ämneskategorier

Infrastrukturteknik

Husbyggnad

DOI

10.1016/j.conbuildmat.2021.124076

Mer information

Senast uppdaterat

2021-07-05