Short-term bond behavior and debonding capacity of prestressed CFRP composites to steel substrate. (1st December 2018)

• Record Type: Journal Article
• Authors: Hosseini, Ardalan; Ghafoori, Elyas; Wellauer, Matthias; Sadeghi Marzaleh, Abdollah; Motavalli, Masoud
• Is Part Of: Engineering structures. Volume 176(2018)
• Page Start: 935
• Page End: 947
• Publication Date: 2018-12-01
• Subjects: Strengthening of steel structures -- Carbon fiber reinforced polymer composite -- Prestressing -- Short-term bond behavior of CFRP-to-steel -- Lap-shear test -- Accelerated curing -- Digital image correlation; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2018.09.025
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Sets of lap-shear and prestress release bond tests were conducted on CFRP-to-steel joints. Feasibility of accelerated curing (AC) of adhesive layer by heating was investigated. A mixed-mode I/II state of fracture governs the debonding failure of prestressed joints. Partly cured state of adhesive layer during the AC can increase the prestress release capacity. A new practical strengthening solution with a partially bonded prestressed CFRP is proposed. Abstract: In this study, the short-term bonding behaviors of prestressed CFRP plates to steel substrates and their debonding capacities have been investigated. For this purpose, single lap-shear and prestress release tests were performed on adhesively bonded CFRP-to-steel joints. The feasibility of accelerated curing (AC) of the adhesive by heating was also investigated based on the conducted tests. Moreover, bond tests with partial prestress release and subsequent lap-shear loading were conducted to examine the feasibility of prestressed strengthening of steel members using AC. A three-dimensional (3D) digital image correlation (DIC) technique was utilized to monitor the bond behavior of CFRP-to-steel joints. Experimental results demonstrated that a mixed-mode I/II (tensile/shear) fracture governs the debonding failure of CFRP-to-steel joints during the prestress release. However, given that the steel substrate cannot undergo tensile failure, a relatively high prestressing force can be transferred to the steel substrate prior to debonding. The experimental results also revealed that the AC of the epoxy adhesive can be an advantageous alternative to the conventional room temperature curing (RTC) for strengthening steel members with prestressed bonded CFRP plates.