Evaluation of bond strength of helically ribbed CFRP bar connections as mechanical anchorage schemes

In spite of their outstanding properties, FRP reinforcing bars still face a series of drawbacks that should be addressed to widen their applications. For example, straight FRP bars must be used because those bars suffer significant strength degradation when curved. This implies that FRP bars resist...

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Main Authors: Sung-Won Yoo, Jaehyun Shin, Jinkyo F. Choo
Format: Article
Language:English
Published: Elsevier 2024-07-01
Series:Case Studies in Construction Materials
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2214509523010070
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author Sung-Won Yoo
Jaehyun Shin
Jinkyo F. Choo
author_facet Sung-Won Yoo
Jaehyun Shin
Jinkyo F. Choo
author_sort Sung-Won Yoo
collection DOAJ
description In spite of their outstanding properties, FRP reinforcing bars still face a series of drawbacks that should be addressed to widen their applications. For example, straight FRP bars must be used because those bars suffer significant strength degradation when curved. This implies that FRP bars resist the slip nearly solely through their bond strength with concrete. In addition, helically ribbed FRP bars exhibit bond strength twice higher than sand coated bars but develop weaker bond characteristics with concrete than the steel rebar. Anchorages are thus needed to improve the bond strength but may be difficult to realize in narrow spaces like joints. Therefore, this study examines the combined use of helically ribbed FRP bars with connections like lap-splice, epoxy-filled tube, coupler or expanded ribs as mechanical anchorages. A total of 36 pullout specimens considering the types of connection as parameter are tested to investigate the eventual effectiveness of the connections in enhancing the bond behavior. The use of two expanded ribs appears to be the best option. The predictions of the bond stress-slip models of current design codes are compared to the experimental data to examine whether these models can simulate accurately the connections.
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spelling doaj.art-ed909bab95db4bca897d965c614696352024-02-16T04:29:04ZengElsevierCase Studies in Construction Materials2214-50952024-07-0120e02826Evaluation of bond strength of helically ribbed CFRP bar connections as mechanical anchorage schemesSung-Won Yoo0Jaehyun Shin1Jinkyo F. Choo2Department of Civil and Environmental Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, South KoreaDepartment of Civil and Environmental Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, South KoreaDepartment of Energy Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, South Korea; Corresponding author.In spite of their outstanding properties, FRP reinforcing bars still face a series of drawbacks that should be addressed to widen their applications. For example, straight FRP bars must be used because those bars suffer significant strength degradation when curved. This implies that FRP bars resist the slip nearly solely through their bond strength with concrete. In addition, helically ribbed FRP bars exhibit bond strength twice higher than sand coated bars but develop weaker bond characteristics with concrete than the steel rebar. Anchorages are thus needed to improve the bond strength but may be difficult to realize in narrow spaces like joints. Therefore, this study examines the combined use of helically ribbed FRP bars with connections like lap-splice, epoxy-filled tube, coupler or expanded ribs as mechanical anchorages. A total of 36 pullout specimens considering the types of connection as parameter are tested to investigate the eventual effectiveness of the connections in enhancing the bond behavior. The use of two expanded ribs appears to be the best option. The predictions of the bond stress-slip models of current design codes are compared to the experimental data to examine whether these models can simulate accurately the connections.http://www.sciencedirect.com/science/article/pii/S2214509523010070Bond strengthHelically ribbed CFRP rebarConnectionsMechanical anchoragesPullout test
spellingShingle Sung-Won Yoo
Jaehyun Shin
Jinkyo F. Choo
Evaluation of bond strength of helically ribbed CFRP bar connections as mechanical anchorage schemes
Case Studies in Construction Materials
Bond strength
Helically ribbed CFRP rebar
Connections
Mechanical anchorages
Pullout test
title Evaluation of bond strength of helically ribbed CFRP bar connections as mechanical anchorage schemes
title_full Evaluation of bond strength of helically ribbed CFRP bar connections as mechanical anchorage schemes
title_fullStr Evaluation of bond strength of helically ribbed CFRP bar connections as mechanical anchorage schemes
title_full_unstemmed Evaluation of bond strength of helically ribbed CFRP bar connections as mechanical anchorage schemes
title_short Evaluation of bond strength of helically ribbed CFRP bar connections as mechanical anchorage schemes
title_sort evaluation of bond strength of helically ribbed cfrp bar connections as mechanical anchorage schemes
topic Bond strength
Helically ribbed CFRP rebar
Connections
Mechanical anchorages
Pullout test
url http://www.sciencedirect.com/science/article/pii/S2214509523010070
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AT jinkyofchoo evaluationofbondstrengthofhelicallyribbedcfrpbarconnectionsasmechanicalanchorageschemes