Volumenske deformacije morta mikroarmiranog ugljičnim vlaknima

master's thesis

• Title (english): Volume deformations of carbon fibre reinforced mortar
• Author: Kiara Milinković
• Mentor: Ana Baričević (mentor)
• Committee member: Ivana Banjad Pečur (predsjednik povjerenstva)
• Committee member: Marija Jelčić Rukavina (član povjerenstva)
• Committee member: Ana Baričević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Civil Engineering; (Materials); Zagreb
• Defense date and country: 2024-07-04, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Civil Engineering

Abstract

Ovaj rad predstavlja istraživanje o razvoju cementnih materijala visokih uporabnih svojstava s dodatkom otpadnih ugljičnih vlakana iz lokalnih izvora, koja nastaju kao nusproizvod prilikom tkanja mrežica za različite kompozitne sustave. Da bi otpadna vlakna mogla ući u širu uporabu, kao dodatak građevinskom materijalu, potrebno je detaljno istraživanje i ispitivanje njihovih svojstava te njihovo ponašanje u cementnom kompozitu. U svrhu toga, u ovom radu su provedena ispitivanja volumenske stabilnosti, konkretno autogeno skupljanje i skupljanje uslijed sušenja, na uzorcima cementnog morta s dodatkom otpadnih ugljičnih vlakna duljina 6 i 12 mm koja su dozirana u volumenskim udjelima od 0.5 %, 1 % i 2 %. Radi usporedbe su također korištene referentna mješavina bez vlakana te mješavine s 1 % udjela tvorničkih vlakana duljine 6 i 12 mm. U radu je opisana problematika i nastanak autogenog skupljanja i skupljanja uslijed sušenja te su objašnjeni mehanizmi utjecaja vlakana na cementni mort u pogledu volumnih deformacija i utjecaja na izmjenu vlage s okolišem. U eksperimentalnom dijelu opisan je postupak pripreme uzoraka te sva provedena ispitivanja u svježem i očvrsnulom stanju. Rezultati ispitivanja upućuju na pozitivan utjecaj otpadnih ugljičnih vlakana, ali i postojanje granične količine vlakana čijim prekoračenjem dolazi do loše obradivosti u svježem stanju te nezadovoljavajućeg ponašanja uzoraka u pogledu skupljanja. Identifikacija takvih nedostataka je ključna za daljnje pronalaženja rješenja i za razvoj novih tehnoloških postupaka.

Abstract (english)

This thesis is a research dealing with the development of high performance cementitious materials with the addition of waste carbon fibres from local sources, which is a by-product of the production of high-performance construction textiles used for various composite systems. In order for waste fibres to be used on a larger scale, as an additive to construction materials, their properties and behaviour in cement composites must be thoroughly researched and tested. For this purpose, tests on volume stability, in particular autogenous shrinkage and drying shrinkage, were carried out in this thesis on cement mortar samples with the addition of 6 and 12 mm long waste carbon fibres, which were dosed in volume fractions of 0.5 %, 1 % and 2 %. A reference mixture without fibres and mixtures with 1% of factory fibres of 6 and 12 mm length were also used for comparison. The thesis describes the problem and cause of autogenous shrinkage and drying shrinkage and explains the mechanisms of fibre influence on cement mortar in terms of volume deformations and influence on moisture exchange with the environment. The experimental part describes the procedure for preparing the samples and the tests carried out in the fresh and hardened state. The test results show that there is a positive influence of waste carbon fibres but also a critical amount of fibres that can be used because when exceeded, this leads to poor workability in the fresh state and unsatisfactory behaviour of the samples in terms of shrinkage. The identification of such behaviour is crucial in order to find solutions and for develop new technological processes in the future.

• Keywords: mort; ugljična vlakna; autogeno skupljanje; skupljanje uslijed sušenja
• Keywords (english): mortar; carbon fibres; autogenous shrinkage; drying shrinkage
• Language: croatian
• URN:NBN: urn:nbn:hr:237:088383
• Project: Number: UIP-2020-02-5242; Title: Cementni kompoziti ojačani otpadnim vlaknima; Title: Cementitious Composites Reinforced with Waste Fibres; Acronym: ReWire; Leader: Ana Baričević; Jurisdiction: Croatia; Funder: Hrvatska zaklada za znanost; Funding stream: Installation Research Projects
• Study programme: Title: Civil Engineering; specializations in: Construction Management, Transportation Engineering, Geotechnical Engineering, Hydraulic Engineering, Structural Engineering, Construction Materials, Theory and Modeling of Structures; Course: Construction Management; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka građevinarstva (magistar/magistra inženjer/inženjerka građevinarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-07-16 10:39:50