Experimental study on bond-sip behaviour between CFRP sheets and lightweight concrete

Mustafa, A; Weekes, L; Augusthus Nelson, L

Abstract

Epoxy bonded fibre reinforced polymer (FRP) composites are widely used for the retrofit of ailing reinforced concrete structures, for both shear and flexure. The behaviour of retrofitted concrete structures is governed by the bond and material characteristics of the epoxy bonded FRP and concrete. Previous studies show that lightweight concrete (LWC), which uses Pulverised Fuel Ash (Lytag) instead of coarse granite aggregates, has significantly lower tensile strength and aggregate interlock compared to normal weight concrete. Shear retrofitted concrete elements are primarily governed by the aggregate interlock and the tensile strength. Thus the study of FRP enhancement techniques in LWC is paramount for limit state design. Many studies have been conducted to understand the bond-slip behaviour between normal weight concrete and FRP composite, where the increasing interfacial (shear) and normal stresses with increasing plastic deformation lead to FRP debonding and/or unexpected FRP rupture failures. However, the bond between the lightweight concrete and FRP has not received much attention. Hence, this paper presents the pull-off experimental results obtained from lightweight concrete prisms with epoxy bonded Carbon FRP (CFRP) materials. The bonded length, width, thickness and the orientation of CFRP sheets were varied, in order to understand the fracture behaviour and the effectiveness of CFRP. The experimental results show that the crack propagation occurred within the concrete, which lead to a brittle failure. Therefore, design of retrofitting of LWC using existing codes of practice should be treated cautiously in limit state design.

Citation

Mustafa, A., Weekes, L., & Augusthus Nelson, L. (2015, September). Experimental study on bond-sip behaviour between CFRP sheets and lightweight concrete. Presented at ACIC 2015, Cambridge, UK

• Presentation Conference Type: Other
• Conference Name: ACIC 2015
• Conference Location: Cambridge, UK
• Start Date: Sep 9, 2015
• End Date: Sep 11, 2015
• Deposit Date: Apr 11, 2016
• Publisher URL: http://acic-conference.com/
• Additional Information: Event Type : Conference