Utjecaj kemijske obrade drvene vune na zapaljivost cementnog kompozita

master's thesis

• Title (english): Influence of chemical treatment of wood woll on wood-cement composite flammability
• Author: Nikolina Leona Serdarević
• Mentor: Juraj Šipušić (mentor)
• Committee member: Juraj Šipušić (predsjednik povjerenstva)
• Committee member: Sanja Lučić Blagojević (član povjerenstva)
• Committee member: Helena Otmačić Ćurković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2016-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Chemical Engineering in Material Development

Abstract

U ovom radu ispitivana je hidratacija portland-cementa uz dodatak aluminijeva hidroksida i vodenog ekstrakta drvene vune. U tu svrhu upotrijebljen je aluminijev hidroksid kao usporivač gorenja, drvena vuna dobivena od crnogoričnog drveća te komercijalni portland-cement. Za ispitivanja na cementnom kompozitu korišten je drvolit®. Metode koje su pritom primijenjene su: kalorimetrija za mjerenje topline hidratacije prilikom vezanja cementa, ispitivanje gorenja za određivanje topline oslobođene prilikom gorenja uzoraka te rendgenska difrakcija uzorka očvrsloga cementa, s ciljem određivanja utjecaja kemijske modifikacije na sastav uzorka. Dobiveni rezultati ukazuju na to da vodeni ekstrakt drvene vune ne utječe na vezanje cementne paste, a isto je uočeno i zamjenom dijela cementnog praha aluminijevim hidroksidom. Dodatkom punila postiže se jedino smanjenje ukupne topline hidratacije, proporcionalno količini punila, što je u skladu s očekivanjima. Također, usporedbom rezultata dobivenih testom gorenja vidljivo je da cementni kompozit, zbog manjeg udjela gorive tvari, oslobađa manje topline u odnosu na čistu drvenu vunu. Rezultati rendgenske difrakcije potvrđuju zaključke prethodnih mjerenja prema kojima nije uočen nastanak nove mineralne faze, tj. dodani aluminijev hidroksid u ovom je sustavu slabo reaktivan. Ispitivana drvena vuna visoke je kvalitete, a sukladno s time i njen je vodeni ekstrakt lišen komponenata koje bi mogle utjecati na vezanje cementne paste. Još jedna uočena prednost dodatka aluminijeva hidroksida u cementni prah jest njegova bjelina kojom se postiže vizualna estetika cementnog kompozita.

Abstract (english)

This study investigates the hydration of Portland cement with the addition of aluminum hydroxide and aqueous wood wool extract. For this purpose the aluminum hydroxide was used as flame retardant, wood wool was obtained from coniferous trees and examinations were carried on commercial Portland-cement. Drvolit® was used as a representative of cement composites in all tests. The applied methods were the calorimetric measurements, to investigate the released heat of hydration of binding cement, burning test, to determine the heat released during the combustion of samples and X-ray diffraction on sample of hardened cement, in order to determine the impact of chemical modification on the composition of the sample. The results show that the aqueous extract of wood wool does not affect the binding of the cement paste, and the same observations were made when replaced part of the cement powder with the aluminum hydroxide. By addition of filler the only noticeable change was reducing the total heat of hydration, proportional to the amount of filler, which was expected. Also, comparing the results obtained from burning test, it is evident that cement composite, as it contains lower proportion of combustible substances, releases less heat compared to pure wood wool. The results of X-ray diffraction confirmed the conclusions of previous measurements, in which wasn`t observed the formation of new mineral phases, i.e. added aluminum hydroxide in this system is poorly reactive. The wood wool, used in this work, was of high quality and in accordance with this, its aqueous extract was devoid of components that could affect the binding of the cement paste. Another perceived advantage of the addition of aluminum hydroxide in the cement powder is its whiteness, which makes the visual aesthetics of cement composites.

• Keywords: drvena vuna; cementni kompozit; gorenje; hidratacija; aluminijev hidroksid
• Keywords (english): wood wool; cement composite; flammability; hydratation; aluminium hydroxide
• Language: croatian
• URN:NBN: urn:nbn:hr:149:238966
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-10-18 11:38:20