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Generic model for predicting the performance of macro-synthetic fibre reinforced concrete for industrial flooring applications
Thesis (MEng)--Stellenbosch University, 2017.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2017
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| _version_ | 1867613813264613376 |
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| access_status_str | Open Access |
| author | Bester, Hermanus Lambertus |
| author2 | Boshoff, William Peter |
| author_browse | Bester, Hermanus Lambertus Boshoff, William Peter |
| author_facet | Boshoff, William Peter Bester, Hermanus Lambertus |
| author_sort | Bester, Hermanus Lambertus |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2017. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/100854 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:42:06.574Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2017 |
| publishDateRange | 2017 |
| publishDateSort | 2017 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/100854 Generic model for predicting the performance of macro-synthetic fibre reinforced concrete for industrial flooring applications Bester, Hermanus Lambertus Boshoff, William Peter Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. Reinforced concrete Reinforced concrete -- Cracking Flooring, Concrete UCTD Thesis (MEng)--Stellenbosch University, 2017. ENGLISH ABSTRACT: The versatility and ready availability of concrete has ensured that this material will continue to be one of great and increasing importance for all types of construction (Domone, 2010). Due to its low tensile strength in comparison with its compressive strength, unreinforced concrete suffers from brittle failure in uni-axial or flexural tension. This drawback can be compensated for by the addition of fibres to the concrete in its fresh state to provide ductility to the brittle concrete matrix. The primary objective of this study is to create generic models which can be implemented to predict the post-cracking performance of Macro-Synthetic Fibre Reinforced Concrete (MSFRC), specifically for industrial flooring applications. To develop the generic models, an extensive background study on FRC is conducted to identify possible factors influencing the performance of MSFRC. Concrete compressive strength, coarse aggregate size, coarse aggregate volume, fibre dosage, and mixing time of MSFRC in its fresh state are identified as the possible influencing factors. Research hypotheses are stated and investigated to determine which of the factors identified have a significant influence on the post-cracking performance of MSFRC, specifically for an experimental macro-synthetic fibre supplied by CHRYSO. Generic linear models are derived to predict the residual flexural tensile strength of MSFRC at specific crack mouth opening displacements (CMOD) and are based on the macro-mechanical tests performed according to EN 14651 (European Norms, 2007). It is concluded that fibre dosage is the only identified factor indicating a significant influence on the residual flexural strength of MSFRC. It is also concluded that the limit of proportionality (LOP), which corresponds to the maximum stress between a CMOD of 0 − 0.05 mm, is only influenced by the compressive strength. Single-fibre pull-out tests (SFPOT) are performed to investigate the effect of compressive strength on the single-fibre performance of the CHRYSO macro-synthetic experimental fibre in its virgin and premixed fibre state. An increase in the performance is evident for the premixed fibres and can be attributed to the mixing process, causing a roughening of the fibre surface and ultimately increasing the fibre-matrix bond characteristics. It is established that compressive strength does not affect the single-fibre performance of the fibre in its virgin state. However, an increase in the performance of the premixed fibres is evident for a decrease in compressive strength, with the explanation of this phenomenon being unclear. Simple- and multiple regression analyses are performed to statistically identify the factors that have a significant effect on the performance of MSFRC and to derive linear models predicting the performance parameters. The regression analyses are based on the obtained macro-mechanical results. As from the visual inspection of the macro-mechanical results, the regression analyses concluded that fibre dosage is the only factor that has a significant effect on the residual flexural tensile strength of MSFRC, and compressive strength as the only factor that influences the LOP. Therefore, the models predicting the performance parameters associated with the residual flexural strength of MSFRC are based on the influence of fibre dosage, and the model predicting the LOP is based on the effect of compressive strength. The models can further be refined with additional experimental data, incorporating a Model Factor (MF) that takes account of additional variation experienced in the construction industry and determining partial material factors (m) to derive suitable design values. AFRIKAANSE OPSOMMING: Die veelsydigheid en toeganklikheid van beton het verseker dat hierdie materiaal sal voortgaan om van groot en toenemende belang te wees vir alle vorme van konstruksie (Domone, 2010). Onbewapende beton ly aan bros faling in enkel-aksiale of buigspanning as gevolg van die materiaal se lae treksterkte in vergelyking met die druksterkte. Daar kan vir hierdie nadeel vergoed word deur die byvoeging van vesels tot die beton in die vars toestand om duktiliteit te verskaf aan die bros beton matriks. Die primêre doel van hierdie navorsingsprojek is om generiese modelle te skep wat geïmplementeer kan word om die na-krakings-gedrag van Makro-Sintetiese Vesel Bewapende Beton (MSVBB) te voorspel, spesifiek met betrekking tot industriële vloer-toepassings. ’n Deeglike agtergrond studie oor Vesel Bewapende Beton (VBB) is uitgevoer om moontlike faktore wat die gedrag van MSVBB kan beinvloed, te identifiseer ten einde die generiese modelle te ontwikkel. Beton druksterkte, growwe aggregaat grootte, growwe aggregaat volume, vesel-volume, en die mengtyd van MSVBB in die vars toestand, is geïdentifiseer as moontlike faktore wat die gedrag van die materiaal kan beïnvloed. Navorsings hipoteses is gestel en ondersoek om vas te stel watter faktore ’n beduidende invloed het op die na-krakings gedrag van MSVBB, met inagneming van ’n eksperimentele makro-sintetiese vesel verskaf deur CHRYSO. Generiese lineêre modelle is afgelei om die oorblywende buig-treksterkte van MSVVB te voorspel by spesifieke Kraak-Mond Opening Verplasings (KMOV) en is gebaseer op die makromeganiese toetse wat uitgevoer is vervolgens EN 14651 (European Norms, 2007). Vesel-volume is geïdentifiseer as die enigste faktor wat ’n beduidende invloed het op die oorblywende buig-treksterkte van MSVVB. Daar is ook bevind dat die Limiet van Proporsionaliteit (LVP), wat ooreenstem met die maksimum spanning tussen ’n KMOV van 0 − 0, 05 mm, slegs beïnvloed word deur die beton druksterkte. Enkelvesel-uittrektoetse is uitgevoer om die effek van beton druksterkte op die enkel-vesel gedrag van die CHRYSO makro-sintetiese eksperimentele vesel, in die ongemengde en voorafgemengde vesel-toestand, te ondersoek. ’n Toename in die gedrag was merkbaar in die geval van die voorafgemengde vesel, en kan toegeskryf word aan die mengproses, wat veroorsaak dat die oppervlak van die sintetiese vesel beskadig word en uiteindelik die bindingseienskappe van die vesel-matriks positief beïnvloed. Daar is vasgestel dat beton-druksterkte nie die gedrag van die enkel-vesel beïnvloed in die ongemengde toestand nie. ’n Toename in die gedrag van die voorafgemengde vesel was merkbaar vir ’n afname in beton druksterkte. Eenvoudige- en meervoudige regressie-analises is uitgevoer om die faktore wat ’n beduidende invloed het op die gedrag van MSVBB, statisties te ontleed en te identifiseer, asook om lineêre generiese modelle te ontwikkel om die prestasie parameters te voorspel. Die regressie-ontledings is gebaseer op die driepuntbuig makro-meganiese resultate. In ooreenstemming met die gevolgtrekkings van die visuele inspeksie van die makro-meganiese resultate, het die regressieontledings getoon dat vesel-volume die enigste faktor is wat ’n beduidende effek het op die na-krakings gedrag van MSVVB, en druksterkte die enigste faktor is wat ’n beduidende effek het op die LVP. Dus is die liniêre modelle wat die prestasie parameters voorspel en verband hou met die na-krakings-gedrag van MSVBB, gebaseer op die invloed van vesel-volume, en die model wat die LVP voorspel gebaseer op die effek van beton-druksterkte. Die lineêre modelle kan verder verfyn word met bykomende eksperimentele data, asook deur ’n Model Faktor (MF) te inkorporeer wat additionele variasies in berekening bring as gevolg van onsekerhede in die konstruksie industrie. Parsïele materiaal faktore ( m) moet ook in ag geneem word om gepaste ontwerp-waardes te bepaal. 2017-02-07T11:56:07Z 2017-03-29T11:38:47Z 2017-02-07T11:56:07Z 2017-03-29T11:38:47Z 2017-03 Thesis http://hdl.handle.net/10019.1/100854 en_ZA Stellenbosch University 203 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Reinforced concrete Reinforced concrete -- Cracking Flooring, Concrete UCTD Bester, Hermanus Lambertus Generic model for predicting the performance of macro-synthetic fibre reinforced concrete for industrial flooring applications |
| title | Generic model for predicting the performance of macro-synthetic fibre reinforced concrete for industrial flooring applications |
| title_full | Generic model for predicting the performance of macro-synthetic fibre reinforced concrete for industrial flooring applications |
| title_fullStr | Generic model for predicting the performance of macro-synthetic fibre reinforced concrete for industrial flooring applications |
| title_full_unstemmed | Generic model for predicting the performance of macro-synthetic fibre reinforced concrete for industrial flooring applications |
| title_short | Generic model for predicting the performance of macro-synthetic fibre reinforced concrete for industrial flooring applications |
| title_sort | generic model for predicting the performance of macro synthetic fibre reinforced concrete for industrial flooring applications |
| topic | Reinforced concrete Reinforced concrete -- Cracking Flooring, Concrete UCTD |
| url | http://hdl.handle.net/10019.1/100854 |
| work_keys_str_mv | AT besterhermanuslambertus genericmodelforpredictingtheperformanceofmacrosyntheticfibrereinforcedconcreteforindustrialflooringapplications |