TY - JOUR
T1 - Bond performance of FRP bars in plain and fiber-reinforced geopolymer under pull-out loading
AU - Peng, Kai Di
AU - Zeng, Jun Jie
AU - Huang, Bo Tao
AU - Huang, Jun Qi
AU - Zhuge, Yan
AU - Dai, Jian Guo
N1 - Funding Information:
This study was supported by the Chinese Guangdong Province R&D Plan for Key Areas (Project Code: 2019B111107002 ) and Hong Kong-Guangzhou Technology and Innovation Partnership Program (Project Code 201807010055 ). Kai-Di Peng acknowledges the Ph.D. studentship offered by The Hong Kong Polytechnic University. Bo-Tao Huang acknowledges the support of the Hong Kong Innovation and Technology Fund (Project Code ITS/077/18FX ) through the Research Talent Hub. Jun-Qi Huang acknowledges the financial support by The Prefabricated Building Research Institute of Anhui Province (Project Code AHZPY20202KF ).
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/10/1
Y1 - 2022/10/1
N2 - Geopolymer-bonded fiber-reinforced polymer (FRP) bar is an emerging strengthening system for concrete structures, owing to the excellent geopolymer/concrete bond and the superior moisture and fire resistance of geopolymer matrix (compared to organic bonding adhesives). To apply this strengthening system, the bond performance between FRP bars and geopolymer should be properly understood. In this study, pull-out tests on 81 specimens with a carbon FRP (CFRP) bar embedded in plain and fiber-reinforced geopolymer were conducted. Key factors including the strength of geopolymer (different mass ratios of fly ash and slag), bar embedded length (5, 10, and 15 times the bar diameter), fiber volume fraction in geopolymer (0, 1%, and 2%), and bar diameters (3 mm, 6 mm, and 10 mm) were explored. The results showed that (1) an increase in geopolymer strength improves the bond strength; (2) increasing embedded length (from 5db to 15db) would reduce the average bond strength (by 20–30%); and (3) adding steel and PVA fibers in geopolymer had a marginal effect on the bond strength. Furthermore, a modified bond strength model of CFRP bars in the geopolymer mortar is proposed based on the current experimental results. The findings lay the groundwork for understanding the bond behaviour of FRP bars in geopolymer, which is critical for the successful application of geopolymer-bonded FRP bar strengthening system.
AB - Geopolymer-bonded fiber-reinforced polymer (FRP) bar is an emerging strengthening system for concrete structures, owing to the excellent geopolymer/concrete bond and the superior moisture and fire resistance of geopolymer matrix (compared to organic bonding adhesives). To apply this strengthening system, the bond performance between FRP bars and geopolymer should be properly understood. In this study, pull-out tests on 81 specimens with a carbon FRP (CFRP) bar embedded in plain and fiber-reinforced geopolymer were conducted. Key factors including the strength of geopolymer (different mass ratios of fly ash and slag), bar embedded length (5, 10, and 15 times the bar diameter), fiber volume fraction in geopolymer (0, 1%, and 2%), and bar diameters (3 mm, 6 mm, and 10 mm) were explored. The results showed that (1) an increase in geopolymer strength improves the bond strength; (2) increasing embedded length (from 5db to 15db) would reduce the average bond strength (by 20–30%); and (3) adding steel and PVA fibers in geopolymer had a marginal effect on the bond strength. Furthermore, a modified bond strength model of CFRP bars in the geopolymer mortar is proposed based on the current experimental results. The findings lay the groundwork for understanding the bond behaviour of FRP bars in geopolymer, which is critical for the successful application of geopolymer-bonded FRP bar strengthening system.
KW - Alkali-activated fly ash/slag
KW - Bond performance
KW - Fiber-reinforced geopolymer
KW - Fiber-reinforced polymer (FRP)
KW - FRP bar
KW - Geopolymer
UR - http://www.scopus.com/inward/record.url?scp=85133945624&partnerID=8YFLogxK
U2 - 10.1016/j.jobe.2022.104893
DO - 10.1016/j.jobe.2022.104893
M3 - Journal article
AN - SCOPUS:85133945624
SN - 2352-7102
VL - 57
JO - Journal of Building Engineering
JF - Journal of Building Engineering
M1 - 104893
ER -