Structural reliability of ultra-high performance fibre reinforced concrete structures

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dc.contributor.advisorDe Koker, Nicoen_ZA
dc.contributor.advisorViljoen, Celesteen_ZA
dc.contributor.advisorBabafemi, Adewumi Johnen_ZA
dc.contributor.authorSimwanda, Lenganji Shadreken_ZA
dc.contributor.otherStellenbosch University. Faculty of Engineering. Dept. of Civil Engineering.en_ZA
dc.date.accessioned2022-11-01T08:05:36Zen_ZA
dc.date.accessioned2023-01-16T12:41:36Zen_ZA
dc.date.available2022-11-01T08:05:36Zen_ZA
dc.date.available2023-01-16T12:41:36Zen_ZA
dc.date.issued2022-12en_ZA
dc.descriptionThesis (PhD) -- Stellenbosch Uiversity, 2022.en_ZA
dc.description.abstractENGLISH ABSTRACT: The current lack of established guidelines for ultra high-performance fibre reinforced concrete (UHPFRC) structures has resulted in their design and construction being based on recommendations adapted from provisions for either conventional reinforced concrete or steel fiber reinforced concrete. Despite these approaches being associated with a fair amount of uncertainty with respect to the performance of the material, the margin of structural safety of UHPFRC structures designed using these guidelines has not been extensively probed in a probabilistic context. Structural reliability provides the most objective and consistent measure of structural safety and allows, in a probabilistic context, comparison of alternative design solutions. As such, it forms a key part of the standardisation of modern structural codes of practice through the prescription of partial safety factors calibrated to conform to minimum levels of safety and is used in probabilistic performance-based design philosophies to target the relevant levels of safety (or performance) directly by explicitly computing the probability of failure. Therefore, to stochastically quantify the level of structural safety in UHPFRC structures, and to take steps towards standardisation for their efficient design, this dissertation presents five studies associated with the development and calibration of methodologies for considering the structural reliability of UHPFRC structures. The first and second studies consider the reliability-based design of UHPFRC beams under the limit states of flexure and shear, respectively. Based on the model uncertainty characterised in these studies, global resistance factors for flexural and shear resistance models of UHPFRC beams are calibrated in the third study. The reliability of existing reinforced concrete beams strengthened with UHPFRC tensile layers is considered in the fourth study. Lastly, a work on Bayesian calibration of temperature-dependent thermal physical properties of UHPFRC and structural reliability of UHPFRC beams under the fire limit state of the load-bearing function is presented.en_ZA
dc.description.abstractAFRIKAANS OPSOMMING: Die huidige gebrek aan gevestigde riglyne vir strukture met ultraho¨eprestasie veselversterkte beton (UHPFRC) het daartoe gelei dat hul ontwerp en konstruksie gebaseer is op aanbevelings wat aangepas is vir ´of konvensionele beton ´of staalveselversterkte beton. Ten spyte daarvan dat hierdie benaderings geassosieer word met ’n redelike mate van onsekerheid met betrekking tot die werkverrigting van die materiaal, is die omvang van strukturele veiligheid van UHPFRC strukture wat ontwerp is met behulp van hierdie riglyne nie omvattend ondersoek in ’n waarskynlikheidskonteks nie. Strukturele betroubaarheid verskaf die mees objektiewe en konsekwente maatstaf van strukturele veiligheid en maak dit moontlik om alternatiewe ontwerpoplossings in ’n waarskynlikheidskonteks te vergelyk. Sodanig vorm dit ’n sleuteldeel van die standaardisering van moderne strukturele praktykkodes deur van gedeeltelike veiligheidsfaktore voor te skryf wat gekalibreer is om te voldoen aan minimum vlakke van veiligheid en word dit gebruik in probabilistiese prestasie-gebaseerde ontwerpfilosofie¨e om die relevante vlakke van veiligheid te teiken (of prestasie) direk deur die waarskynlikheid van mislukking uitdruklik te bereken. Om die vlak van strukturele veiligheid in UHPFRC-strukture stogasties te kwantifiseer, en om stappe te neem in die rigting van standaardisering vir hul doeltreffende ontwerp, bied hierdie proefskrif vyf studies aan wat verband hou met die ontwikkeling en kalibrering van metodologie ¨e vir die oorweging van die strukturele betroubaarheid van UHPFRC-strukture. Die eerste en tweede studies oorweeg die betroubaarheid-gebaseerde ontwerp van UHPFRC-balke onder die grenstoestande van buiging en skuif, onderskeidelik. Gebaseer op die modelonsekerheid wat in hierdie studies gekenmerk word, word wˆereldwyd weerstandsfaktore vir buig- en skuifweerstandsmodelle van UHPFRC-balke in die derde studie gekalibreer. Die betroubaarheid van bestaande gewapende betonbalke wat met UHPFRC-treklae versterk is, word in die vierde studie oorweeg. Laastens word ’n werk oor Bayesiaanse kalibrasie van temperatuurafhanklike termiese fisiese eienskappe van UHPFRC en strukturele betroubaarheid van UHPFRC-balke onder die brandgrenstoestand van die lasdraende funksie aangebied.af_ZA
dc.description.versionDoctoralen_ZA
dc.format.extentxxv, 174 pages : illustrationsen_ZA
dc.identifier.urihttp://hdl.handle.net/10019.1/125926en_ZA
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : Stellenbosch Universityen_ZA
dc.rights.holderStellenbosch Universityen_ZA
dc.subjectFiber-reinforced concrete -- Reliabilityen_ZA
dc.subjectConcrete -- Mechanical propertiesen_ZA
dc.subjectEngineering modelsen_ZA
dc.subjectGlobal resistance factorsen_ZA
dc.subjectBayesian calibrationen_ZA
dc.subjectStructural engineeringen_ZA
dc.subjectReinforced concrete -- Thermal propertiesen_ZA
dc.subjectConstruction industry -- Safety measuresen_ZA
dc.subjectUCTDen_ZA
dc.titleStructural reliability of ultra-high performance fibre reinforced concrete structuresen_ZA
dc.typeThesisen_ZA
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