Progressive collapse behaviour of precast concrete structures with advanced joints

Progressive collapse, where widespread structural failure is triggered by localised failures, is regarded as a critical concern. In this context, offering a threat-independent approach, the alternate load path (ALP) method simplifies progressive collapse analysis by considering a single-column remov...

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Main Author: Nguyen, Van Hung
Other Authors: Tan Kang Hai
Format: Thesis-Doctor of Philosophy
Language:English
Published: Nanyang Technological University 2024
Subjects:
Online Access:https://hdl.handle.net/10356/177412
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Institution: Nanyang Technological University
Language: English
id sg-ntu-dr.10356-177412
record_format dspace
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering
Progressive collapse
Precast concrete structure
Headed bar
Additional bar layer
Plastic hinge relocation
spellingShingle Engineering
Progressive collapse
Precast concrete structure
Headed bar
Additional bar layer
Plastic hinge relocation
Nguyen, Van Hung
Progressive collapse behaviour of precast concrete structures with advanced joints
description Progressive collapse, where widespread structural failure is triggered by localised failures, is regarded as a critical concern. In this context, offering a threat-independent approach, the alternate load path (ALP) method simplifies progressive collapse analysis by considering a single-column removal scenario. However, most ALP studies primarily concentrated on reinforced concrete (RC) or precast concrete (PC) structures with convential joint detailing, leaving a knowledge gap in understanding of progressive collapse of precast concrete (PC) structures with wet connections and special joint detailing. This knowledge gap motivates research into static behaviour of the PC substructures against progressive collapse. To improve inaccuracy in previous model predictions of structural response, a refined component-based model (CBM) was proposed for RC frames with conventional and special joint detailing against progressive collapse. Through numerical analysis, advantages of incorporating an additional bar layer (ABL) and plastic hinge relocation (PHR) in the beam-joint region for enhancing collapse resistance of RC frames were illuminated. To verify these findings, three types of PC wet joints, employing (i) headed bars (Type H), (ii) providing an ABL (Type A), and (iii) incorporating PHR with X-bent bar (Type X) in the beam-joint region, were developed. Subsequently, two sets of static tests on these joints (Series I and II), along with a component pull-out test on headed bars, were conducted. In Series I, progressive collapse of four interior joints under a middle column removal scenario (MCRS) was investigated, ultimately confirming practical feasibility of the proposed joint detailing. In addition to flexural action, compressive arch action (CAA) and catenary action (CA) were mobilised against collapse. Moreover, superior collapse resistance of Type X compared to Type H and Type A joints was observed. Secondly, the pull-out test results highlighted a pivotal role of bearing force in anchorage strength of headed bars and strain behaviour. Building upon this insight, a macro bond-slip model was proposed for headed bars, incorporated into CBMs, and verified against the test results from Series I with reasonable accuracy. A parametric study based on the verified model shed light on collapse behaviour of penultimate joints under a penultimate exterior column removal scenario (PECRS). In addition to test Series I, the experimental programme in Series II focused on progressive collapse behaviour of exterior joints. This series involved two exterior joint specimens, both subjected to a PECRS. The investigations in Series I and II provided insights into progressive collapse behaviour of interior and exterior PC joints. However, understanding progressive collapse behaviour in the context of a building structure is vital for robustness and mitigation. Hence, a simplified finite element model was proposed, integrating joint-level findings from Series I and II to examine the overall response of a PC building following progressive collapse. Moreover, the impact of slab contribution, level of removed column, column removal scenarios, and modelling technique on progressive collapse behaviour of PC structures was shed light.
author2 Tan Kang Hai
author_facet Tan Kang Hai
Nguyen, Van Hung
format Thesis-Doctor of Philosophy
author Nguyen, Van Hung
author_sort Nguyen, Van Hung
title Progressive collapse behaviour of precast concrete structures with advanced joints
title_short Progressive collapse behaviour of precast concrete structures with advanced joints
title_full Progressive collapse behaviour of precast concrete structures with advanced joints
title_fullStr Progressive collapse behaviour of precast concrete structures with advanced joints
title_full_unstemmed Progressive collapse behaviour of precast concrete structures with advanced joints
title_sort progressive collapse behaviour of precast concrete structures with advanced joints
publisher Nanyang Technological University
publishDate 2024
url https://hdl.handle.net/10356/177412
_version_ 1814047318580658176
spelling sg-ntu-dr.10356-1774122024-06-03T06:51:19Z Progressive collapse behaviour of precast concrete structures with advanced joints Nguyen, Van Hung Tan Kang Hai School of Civil and Environmental Engineering Protective Technology Research Centre CKHTAN@ntu.edu.sg Engineering Progressive collapse Precast concrete structure Headed bar Additional bar layer Plastic hinge relocation Progressive collapse, where widespread structural failure is triggered by localised failures, is regarded as a critical concern. In this context, offering a threat-independent approach, the alternate load path (ALP) method simplifies progressive collapse analysis by considering a single-column removal scenario. However, most ALP studies primarily concentrated on reinforced concrete (RC) or precast concrete (PC) structures with convential joint detailing, leaving a knowledge gap in understanding of progressive collapse of precast concrete (PC) structures with wet connections and special joint detailing. This knowledge gap motivates research into static behaviour of the PC substructures against progressive collapse. To improve inaccuracy in previous model predictions of structural response, a refined component-based model (CBM) was proposed for RC frames with conventional and special joint detailing against progressive collapse. Through numerical analysis, advantages of incorporating an additional bar layer (ABL) and plastic hinge relocation (PHR) in the beam-joint region for enhancing collapse resistance of RC frames were illuminated. To verify these findings, three types of PC wet joints, employing (i) headed bars (Type H), (ii) providing an ABL (Type A), and (iii) incorporating PHR with X-bent bar (Type X) in the beam-joint region, were developed. Subsequently, two sets of static tests on these joints (Series I and II), along with a component pull-out test on headed bars, were conducted. In Series I, progressive collapse of four interior joints under a middle column removal scenario (MCRS) was investigated, ultimately confirming practical feasibility of the proposed joint detailing. In addition to flexural action, compressive arch action (CAA) and catenary action (CA) were mobilised against collapse. Moreover, superior collapse resistance of Type X compared to Type H and Type A joints was observed. Secondly, the pull-out test results highlighted a pivotal role of bearing force in anchorage strength of headed bars and strain behaviour. Building upon this insight, a macro bond-slip model was proposed for headed bars, incorporated into CBMs, and verified against the test results from Series I with reasonable accuracy. A parametric study based on the verified model shed light on collapse behaviour of penultimate joints under a penultimate exterior column removal scenario (PECRS). In addition to test Series I, the experimental programme in Series II focused on progressive collapse behaviour of exterior joints. This series involved two exterior joint specimens, both subjected to a PECRS. The investigations in Series I and II provided insights into progressive collapse behaviour of interior and exterior PC joints. However, understanding progressive collapse behaviour in the context of a building structure is vital for robustness and mitigation. Hence, a simplified finite element model was proposed, integrating joint-level findings from Series I and II to examine the overall response of a PC building following progressive collapse. Moreover, the impact of slab contribution, level of removed column, column removal scenarios, and modelling technique on progressive collapse behaviour of PC structures was shed light. Doctor of Philosophy 2024-05-24T12:59:50Z 2024-05-24T12:59:50Z 2024 Thesis-Doctor of Philosophy Nguyen, V. H. (2024). Progressive collapse behaviour of precast concrete structures with advanced joints. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/177412 https://hdl.handle.net/10356/177412 10.32657/10356/177412 en NTU Ref: 2018–1451 This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0). application/pdf Nanyang Technological University