Behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / Sobia Anwar Qazi

Behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / Sobia Anwar Qazi

Fibre-reinforced polymer (FRP) strengthened and unstrengthened reinforced concrete (RC) structures are susceptible to intense deterioration when exposed to elevated temperatures, particularly in the incident of fire. FRP has the tendency to lose bond with the substrate due to the low glass transitio...

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Main Author: Qazi, Sobia Anwar
Format: Thesis
Language:English
Published: 2016
Subjects:
Structural engineering
Online Access:http://ir.uitm.edu.my/id/eprint/28033/
http://ir.uitm.edu.my/id/eprint/28033/1/TP_SOBIA%20ANWAR%20QAZI%20EC%2016_5.pdf
id uitm-28033
recordtype eprints
repository_type Digital Repository
institution_category Local University
institution Universiti Teknologi MARA
building UiTM Institutional Repository
collection Online Access
language English
topic Structural engineering
spellingShingle Structural engineering
Qazi, Sobia Anwar
Behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / Sobia Anwar Qazi
description Fibre-reinforced polymer (FRP) strengthened and unstrengthened reinforced concrete (RC) structures are susceptible to intense deterioration when exposed to elevated temperatures, particularly in the incident of fire. FRP has the tendency to lose bond with the substrate due to the low glass transition temperature (Tg) of epoxy; the key component of FRP matrix. Previously, various types of high performance cementitious composites (HPCC) were explored for the protection of RC structural members against elevated temperature. However, there is an inadequate information on the influence of elevated temperature on the ultra-high performance fibre reinforced cementitious composites (UHPFRCC) containing ground granulated blast furnace slag (GGBS) and/or fly ash (FA) as a replacement of high alumina cement (HAC) in conjunction with hybrid fibres (basalt and polypropylene (PP) fibres). This could be a prospective fire resisting material for the structural components. The influence of elevated temperatures on the compressive, flexural and tensile strength of UHPFRCC, made of HAC-GGBS and hybrid fibres, was examined in this study along with complete microstructural, chemical and thermal analysis. Total fourteen (14) mixes were developed. Besides control sample (without fibres), three other samples, containing 0.5%, 1% and 1.5% of basalt fibres by total weight of mix and 1 kg/m3 of PP fibres, were prepared and tested. Another mix was also prepared with only 1 kg/m3 of PP fibres. Nine (9) more mixes were developed with the replacement of GGBS with FA. Each of the samples were retained at ambient temperature as well as exposed to 400°C, 700°C and 1000°C followed by residual mechanical (compressive, tensile and flexural), thermal (TC, TG and DSC analysis) and microstructural (XRD, ESEM and MIP) testing after 28 and 56 days of conventional curing. Investigation of results disclosed that the use of hybrid fibres significantly helped to improve the ambient temperature compressive and flexural strength of UHPFRCC, which was found to be 80 MPa and 14.3 MPa respectively. However, the optimum residual compressive strength was marked by UHPFRCC- CP (with PP fibres only), equally after both curing days (28 and 56 days), i.e. 41%. In addition, the highest residual flexural strength, after 28 and 56 days of curing, was marked by UHPFRCC- CP and UHPFRCC- CB2 (1 kg/m3 of PP fibres + 1% of basalt fibres) i.e. 39% and 48.5% respectively. Through statistical analysis by response surface methodology (RSM), regression models were also developed for UHPFRCC based on the factors affecting residual mechanical strength. After residual mechanical testing, UHPFRCC-CP and UHPFRCC-F2B1 were selected as best mix to be cladded over full scale Carbon fibre reinforced polymer (CFRP)-strengthened and unstrengthened RC columns and tested under ASTM El 19 fire. Total seven short RC column specimens were cast, using grade 40 concrete, including unstrengthened and CFRP-strengthened with and without two different types of UHPFRCC cladding. The size of the full-scale columns was 200 mm x 200 mm x 2640 mm. Results have shown that cladded UHPFRCC proved to be the potential fire resistant coating for RC columns and increased the time of failure significantly for both CFRP strengthened and unstrengthened RC columns. Among both types of claddings, UHPFRCC-CP found to be the most effective in protecting unstrengthened as well as CFRP-strengthened columns. Besides, it also increased the time to reach the Tg of CFRP composite by 20 minutes as compared to the unprotected CFRP-strengthened column.
format Thesis
author Qazi, Sobia Anwar
author_facet Qazi, Sobia Anwar
author_sort Qazi, Sobia Anwar
title Behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / Sobia Anwar Qazi
title_short Behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / Sobia Anwar Qazi
title_full Behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / Sobia Anwar Qazi
title_fullStr Behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / Sobia Anwar Qazi
title_full_unstemmed Behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / Sobia Anwar Qazi
title_sort behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / sobia anwar qazi
publishDate 2016
url http://ir.uitm.edu.my/id/eprint/28033/
http://ir.uitm.edu.my/id/eprint/28033/1/TP_SOBIA%20ANWAR%20QAZI%20EC%2016_5.pdf
first_indexed 2023-09-18T23:19:28Z
last_indexed 2023-09-18T23:19:28Z
_version_ 1777419333761236992
spelling uitm-280332020-02-04T09:01:15Z http://ir.uitm.edu.my/id/eprint/28033/ Behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / Sobia Anwar Qazi Qazi, Sobia Anwar Structural engineering Fibre-reinforced polymer (FRP) strengthened and unstrengthened reinforced concrete (RC) structures are susceptible to intense deterioration when exposed to elevated temperatures, particularly in the incident of fire. FRP has the tendency to lose bond with the substrate due to the low glass transition temperature (Tg) of epoxy; the key component of FRP matrix. Previously, various types of high performance cementitious composites (HPCC) were explored for the protection of RC structural members against elevated temperature. However, there is an inadequate information on the influence of elevated temperature on the ultra-high performance fibre reinforced cementitious composites (UHPFRCC) containing ground granulated blast furnace slag (GGBS) and/or fly ash (FA) as a replacement of high alumina cement (HAC) in conjunction with hybrid fibres (basalt and polypropylene (PP) fibres). This could be a prospective fire resisting material for the structural components. The influence of elevated temperatures on the compressive, flexural and tensile strength of UHPFRCC, made of HAC-GGBS and hybrid fibres, was examined in this study along with complete microstructural, chemical and thermal analysis. Total fourteen (14) mixes were developed. Besides control sample (without fibres), three other samples, containing 0.5%, 1% and 1.5% of basalt fibres by total weight of mix and 1 kg/m3 of PP fibres, were prepared and tested. Another mix was also prepared with only 1 kg/m3 of PP fibres. Nine (9) more mixes were developed with the replacement of GGBS with FA. Each of the samples were retained at ambient temperature as well as exposed to 400°C, 700°C and 1000°C followed by residual mechanical (compressive, tensile and flexural), thermal (TC, TG and DSC analysis) and microstructural (XRD, ESEM and MIP) testing after 28 and 56 days of conventional curing. Investigation of results disclosed that the use of hybrid fibres significantly helped to improve the ambient temperature compressive and flexural strength of UHPFRCC, which was found to be 80 MPa and 14.3 MPa respectively. However, the optimum residual compressive strength was marked by UHPFRCC- CP (with PP fibres only), equally after both curing days (28 and 56 days), i.e. 41%. In addition, the highest residual flexural strength, after 28 and 56 days of curing, was marked by UHPFRCC- CP and UHPFRCC- CB2 (1 kg/m3 of PP fibres + 1% of basalt fibres) i.e. 39% and 48.5% respectively. Through statistical analysis by response surface methodology (RSM), regression models were also developed for UHPFRCC based on the factors affecting residual mechanical strength. After residual mechanical testing, UHPFRCC-CP and UHPFRCC-F2B1 were selected as best mix to be cladded over full scale Carbon fibre reinforced polymer (CFRP)-strengthened and unstrengthened RC columns and tested under ASTM El 19 fire. Total seven short RC column specimens were cast, using grade 40 concrete, including unstrengthened and CFRP-strengthened with and without two different types of UHPFRCC cladding. The size of the full-scale columns was 200 mm x 200 mm x 2640 mm. Results have shown that cladded UHPFRCC proved to be the potential fire resistant coating for RC columns and increased the time of failure significantly for both CFRP strengthened and unstrengthened RC columns. Among both types of claddings, UHPFRCC-CP found to be the most effective in protecting unstrengthened as well as CFRP-strengthened columns. Besides, it also increased the time to reach the Tg of CFRP composite by 20 minutes as compared to the unprotected CFRP-strengthened column. 2016 Thesis NonPeerReviewed text en http://ir.uitm.edu.my/id/eprint/28033/1/TP_SOBIA%20ANWAR%20QAZI%20EC%2016_5.pdf Qazi, Sobia Anwar (2016) Behaviour of ultra high performance fibre reinforced cementitious composites for enhancing the fire endurance of structural members / Sobia Anwar Qazi. PhD thesis, Universiti Teknologi MARA.

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