An Anchoring Groove Technique to Enhance the Bond Behavior between Heat-Damaged Concrete and CFRP Composites

Rajai Al-Rousan,Mohammad Al-Tahat

doi:10.3390/buildings10120232

Rajai Al-Rousan, Mohammad Al-Tahat

Open Access

https://doi.org/10.3390/buildings10120232

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Journal: Buildings	Publication Date: Dec 7, 2020
Citations: 22	License type: CC BY 4.0

Affiliation: Jordan University of Science and Technology

Abstract

This experimental study was conducted to evaluate the effectiveness of using carbon fiber-reinforced polymer (CFRP) composites with special anchoring grooves, specifically in terms of the ability of the concrete–CFRP bond to withstand elevated temperatures. The obtained findings of this experiment clearly highlighted the effectiveness of the direction of the anchoring grooves on the behavior of the concrete–CFRP bonding area. The results also showed that high temperatures lessen the bond’s strength and the ultimate slippage. On the other hand, this study showed that increasing the length of the CFRP sheet resulted in enhancement of the bond’s strength and slippage. When exposed to temperatures above 500 °C, the structures’ residual splitting and compression strength decreased significantly, resulting in the bond’s strength reducing to 67% and the slippage to 19%, with respect to the control samples. In the non-grooved and vertically grooved beams, the CFRP–concrete bond showed a skin-peeling type of failure. It appeared, also, that the temperature and the number of anchored grooves significantly affected the bonding area of the surface; as the surface was exposed to failure in adhesion, more concrete remained attached to the CFRP composite, signifying a stronger attachment.

Highlights

Concrete has been the most extensively used material for structures for decades
The quality of the reinforcement by carbon fiber-reinforced polymer (CFRP) is mainly governed by the behavior of the CFRP–concrete bond
The cylinder was gradually pulled until the CFRP sheets de-bonded

Summary

Introduction

Concrete has been the most extensively used material for structures for decades. concrete is classified as a brittle material, with a low strain limit and tensile strength capacity. The quality of the reinforcement by CFRPs is mainly governed by the behavior of the CFRP–concrete bond When this bond is not strong enough, de-bonding occurs, which is a disadvantageous brittle failure [6]. Research has been conducted to study the behavior of the CFRP–concrete bond-slip and its mode of failure at the adhered elements. These studies have focused on the concrete tensile and compressive strengths [7,8], the dimensions of the CFRP composites [9,10], hole configurations [11], preparation and roughness of the concrete bonded surface [12], and the CFRP composite anchorage system [13]. The separation of the concrete cover and intermediate induced cracks are examples of the most frequently occurring de-bonding failures due to excessive external loads [6,7]

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