Innovative prestressing method for externally bonded CFRP laminates without mechanical anchorage
Artikel i vetenskaplig tidskrift, 2019

Strengthening of reinforced concrete (RC) structures by externally bonded carbon fiber reinforced polymer (CFRP) laminates has been widely accepted as an effective and cost-efficient method. It is well known that advantages offered by the bonded CFRP laminates can be further increased by prestressing the laminates prior to bonding. Mechanical anchors are essential, in this case, to prevent debonding since interfacial stress at areas close to the ends of the strengthening laminate is several times higher than the strength of the concrete substrate. Common anchorage solutions often consist of bolted metallic plates to clamp the prestressed CFRP laminate. Besides labor-intensive installation operation, the anchor plates are vulnerable to galvanic corrosion, which further complicates the inspection and increases the maintenance costs. There are also doubts about the long-term performance of such anchorage systems as it highly depends on the quality of the adhesive layer between the plate and laminate, and the level of pre-tension in clamping bolts. This paper presents the work conducted at Chalmers University of Technology on the development of an innovative prestressing method and a tool which allow for the application of prestressed CFRP laminates without mechanical anchors. The principles of the novel method and the prestressing system are explained. Experimental and numerical work carried out on an RC beam strengthened with this method is presented. Results indicate that CFRP laminates with high prestressing forces (approximately 30% of CFRP tensile strength) can be safely anchored without the need for mechanical anchors. Numerical results based on finite element analyses show that the proposed prestressing method can reduce the interfacial shear stresses in the CFRP-concrete adhesive joint below the bond strength with a reasonable safety margin.

Prestressing

Strengthening

Debonding

Experimen

Anchorage

Finite element

Carbon fiber reinforced polymer (CFRP)

Externally bonded

Reinforced concrete (RC)

Författare

Jincheng Yang

Chalmers, Arkitektur och samhällsbyggnadsteknik, Konstruktionsteknik

Reza Haghani Dogaheh

Chalmers, Arkitektur och samhällsbyggnadsteknik, Konstruktionsteknik

Mohammad al-Emrani

Chalmers, Arkitektur och samhällsbyggnadsteknik, Konstruktionsteknik

Engineering Structures

01410296 (ISSN) 18737323 (eISSN)

Vol. 197

Hållbar renovering av befintliga broar (SUREBridge)

Europeiska kommissionen (FP7), 2015-10-01 -- 2018-12-31.

Styrkeområden

Building Futures (2010-2018)

Ämneskategorier

Infrastrukturteknik

Husbyggnad

DOI

10.1016/j.engstruct.2019.109416

Mer information

Senast uppdaterat

2019-09-26