Cargando…

Experimental Investigation on Interface Performance of UHPC-Strengthened NC Structure through Push-Out Tests

Strengthening concrete structures with ultra-high performance concrete (UHPC) can both improve the bearing capacity of the original normal concrete (NC) structure and prolong the service life of the structure due to the high strength and durability of UHPC. The key to the synergistic work of the UHP...

Descripción completa

Detalles Bibliográficos
Autores principales: Zhao, Yun-Chuan, Lei, Hong-Gang, Guo, Lang-Kuo, Lu, Guo-Yun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10004257/
https://www.ncbi.nlm.nih.gov/pubmed/36902882
http://dx.doi.org/10.3390/ma16051766
_version_ 1784904788423475200
author Zhao, Yun-Chuan
Lei, Hong-Gang
Guo, Lang-Kuo
Lu, Guo-Yun
author_facet Zhao, Yun-Chuan
Lei, Hong-Gang
Guo, Lang-Kuo
Lu, Guo-Yun
author_sort Zhao, Yun-Chuan
collection PubMed
description Strengthening concrete structures with ultra-high performance concrete (UHPC) can both improve the bearing capacity of the original normal concrete (NC) structure and prolong the service life of the structure due to the high strength and durability of UHPC. The key to the synergistic work of the UHPC-strengthened layer and the original NC structures lies in the reliable bonding of their interfaces. In this research study, the shear performance of the UHPC–NC interface was investigated by the direct shear (push-out test) test method. The effects of different interface preparation methods (smoothing, chiseling, and planting straight and hooked rebars) and different aspect ratios of planted rebars on the failure mode and shear performance of the pushed-out specimens were studied. Seven groups of push-out specimens were tested. The results show that the interface preparation method can significantly affect the failure mode of the UHPC–NC interface, which is specifically divided into interface failure, planted rebar pull-out, and NC shear failure. The critical aspect ratio for the pull-out or anchorage of planted rebars in UHPC is around 2. The interface shear strength of straight-planted rebar interface preparation is significantly improved compared with that of the chiseled and smoothened interfaces, and as the embedding length of the planted rebar becomes longer, it first increases greatly and then tends to be stable when the rebar planted in UHPC is fully anchored. The shear stiffness of UHPC–NC increases with the increase of the aspect ratio of planted rebars. A design recommendation based on the experimental results is proposed. This research study supplements the theoretical basis of the interface design of UHPC-strengthened NC structures.
format Online
Article
Text
id pubmed-10004257
institution National Center for Biotechnology Information
language English
publishDate 2023
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-100042572023-03-11 Experimental Investigation on Interface Performance of UHPC-Strengthened NC Structure through Push-Out Tests Zhao, Yun-Chuan Lei, Hong-Gang Guo, Lang-Kuo Lu, Guo-Yun Materials (Basel) Article Strengthening concrete structures with ultra-high performance concrete (UHPC) can both improve the bearing capacity of the original normal concrete (NC) structure and prolong the service life of the structure due to the high strength and durability of UHPC. The key to the synergistic work of the UHPC-strengthened layer and the original NC structures lies in the reliable bonding of their interfaces. In this research study, the shear performance of the UHPC–NC interface was investigated by the direct shear (push-out test) test method. The effects of different interface preparation methods (smoothing, chiseling, and planting straight and hooked rebars) and different aspect ratios of planted rebars on the failure mode and shear performance of the pushed-out specimens were studied. Seven groups of push-out specimens were tested. The results show that the interface preparation method can significantly affect the failure mode of the UHPC–NC interface, which is specifically divided into interface failure, planted rebar pull-out, and NC shear failure. The critical aspect ratio for the pull-out or anchorage of planted rebars in UHPC is around 2. The interface shear strength of straight-planted rebar interface preparation is significantly improved compared with that of the chiseled and smoothened interfaces, and as the embedding length of the planted rebar becomes longer, it first increases greatly and then tends to be stable when the rebar planted in UHPC is fully anchored. The shear stiffness of UHPC–NC increases with the increase of the aspect ratio of planted rebars. A design recommendation based on the experimental results is proposed. This research study supplements the theoretical basis of the interface design of UHPC-strengthened NC structures. MDPI 2023-02-21 /pmc/articles/PMC10004257/ /pubmed/36902882 http://dx.doi.org/10.3390/ma16051766 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Zhao, Yun-Chuan
Lei, Hong-Gang
Guo, Lang-Kuo
Lu, Guo-Yun
Experimental Investigation on Interface Performance of UHPC-Strengthened NC Structure through Push-Out Tests
title Experimental Investigation on Interface Performance of UHPC-Strengthened NC Structure through Push-Out Tests
title_full Experimental Investigation on Interface Performance of UHPC-Strengthened NC Structure through Push-Out Tests
title_fullStr Experimental Investigation on Interface Performance of UHPC-Strengthened NC Structure through Push-Out Tests
title_full_unstemmed Experimental Investigation on Interface Performance of UHPC-Strengthened NC Structure through Push-Out Tests
title_short Experimental Investigation on Interface Performance of UHPC-Strengthened NC Structure through Push-Out Tests
title_sort experimental investigation on interface performance of uhpc-strengthened nc structure through push-out tests
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10004257/
https://www.ncbi.nlm.nih.gov/pubmed/36902882
http://dx.doi.org/10.3390/ma16051766
work_keys_str_mv AT zhaoyunchuan experimentalinvestigationoninterfaceperformanceofuhpcstrengthenedncstructurethroughpushouttests
AT leihonggang experimentalinvestigationoninterfaceperformanceofuhpcstrengthenedncstructurethroughpushouttests
AT guolangkuo experimentalinvestigationoninterfaceperformanceofuhpcstrengthenedncstructurethroughpushouttests
AT luguoyun experimentalinvestigationoninterfaceperformanceofuhpcstrengthenedncstructurethroughpushouttests