doctoral thesis
Fire resistance of concrete with crushed bricks and roof tiles

Ivana Miličević (2014)
Metadata
TitlePožarna otpornost betona s opekarskim lomom kao agregatom
AuthorIvana Miličević
Mentor(s)Dubravka Bjegović
Abstract
Recikliranje drobljenog glinenog crijepa i opeke je ekološki prihvatljiv način njihovog zbrinjavanja. Jedan od načina ponovne upotrebe jest upotreba kroz reciklirani agregat, dobiven drobljenjem glinene opeke i crijepa nastalih kao lom pri njihovoj proizvodnji. Budući da primjena betona s recikliranim opekarskim lomom nije uvelike raširena, potrebno je dodatno istražiti mogućnost primjene u područjima u kojima takav beton pokazuje bolja svojstva od betona s prirodnim agregatom. Uzimajući u obzir da beton s recikliranim opekarskim lomom, na temelju dosada provedenih istraživanja, ima bolja toplinska svojstva i otpornost na požar od običnog betona s prirodnim agregatom, u radu je istražena mogućnost primjene betona od recikliranog opekarskog loma u području požarne otpornosti za predgotovljene betonske stropne blokove. Prikazan je pregled područja trenutne primjene betona s drobljenim opekarskim lomom kao agregatom, ciljeva i mogućih ograničenja koja se odnose na istraživanje upotrebe betona s drobljenim opekarskim lomom u novim konstrukcijskim aplikacijama. Prikazani su zahtjevi koje je potrebno zadovoljiti kako bi se osigurala primjena opekarskog loma kao agregata za beton u novim predgotovljenim betonskim stropnim sustavima. Eksperimentalna ispitivanja imaju značajnu ulogu u području inovativne upotrebe postojećih materijala, poboljšanju i razvoju njihovog proizvodnog procesa. Postavljeni cilj eksperimentalnog ispitivanja može uzrokovati komplicirani postupak provedbe ispitivanja zbog velikog broja varijabli koje mogu utjecati na konačni cilj. Stoga je u radu odabran postupak planiranja eksperimenta kojim su se uzele u obzir najvažnije varijable i time smanjio opseg ispitivanja, a da pri tome nije ugrožena točnost rezultata ispitivanja. U radu su provedena preliminarna eksperimentalna ispitivanja svojstava komponenti betona i samog betona s drobljenim opekarskim lomom kao agregatom te je opisan plan eksperimentalnog ispitivanja temeljem kojega su ispitivanja provedena. Proveden je odabir prihvatljivih mješavina betona na temelju eksperimenta i na temelju matematičkog modela. Optimalne mješavine odabrane su višekriterijskim odlučivanjem. Odabrane optimalne mješavine ispitane su na razini materijala u pogledu fizikalno-mehaničkih i trajnosnih svojstava nakon izloženosti temperaturama od 20°C, 200°C, 600°C, 800°i 1000°C. Na temelju rezultata ispitivanja optimalnih mješavina odabrana je jedna mješavina s najboljim svojstvima u svježem i očvrslom stanju s obzirom na moguću primjenu u stropnim blokovima. Ispitivanja optimalne mješavine provedena su i na razini elementa konstrukcije – stropnog bloka. Izrađeni su i ispitani stropni blokovi s opekarskim lomom kao agregatom. Ispitana su njihova svojstva na sobnoj temperaturi te rezidualna svojstva nakon izlaganja visokim temperaturama, a sve prema zahtjevima norme HRN EN 15037-2:2009: Stropni sustavi sastavljeni od nosača i blokova – 2. dio: Betonski blokovi. Također je proveden dokaz nosivosti stropnih blokova prije i nakon izlaganja visokim temperaturama. Zaključno je dokazano da je moguća izrada blokova ispune za predgotovljene stropne konstrukcije povećane požarne otpornosti kao rezultata definiranja primjene betona s opekarskim lomom kao agregatom.
Keywordscrushed brick crushed roof tile concrete design of experiment floor system optimization
Parallel title (English)Fire resistance of concrete with crushed bricks and roof tiles
Committee MembersIvanka Netinger Grubeša (committee chairperson)
Dubravka Bjegović (committee member)
Dragan Morić (committee member)
GranterSveučilište Josipa Jurja Strossmayera u Osijeku
Građevinski fakultet Osijek
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineTECHNICAL SCIENCES
Civil Engineering
Supporting Structures
UDK624/625
APPLIED SCIENCES. MEDICINE. TECHNOLOGY
Civil and structural engineering. Civil engineering of land transport. Railway engineering. Highway engineering
Study programme typeuniversity
Study levelpostgraduate
Study programmePostgraduate university study program in civil engineering
Academic title abbreviationdr. sc.
Genredoctoral thesis
Language Croatian
Defense date2014-10-17
Parallel abstract (English)
Recycling of crushed clay brick and roof tile is an environmentally friendly way of their disposal. During the production and transport a part of produced bricks and roof tiles becomes broken in the factory and it is crushed straight away in the factory. One way to reuse crushed bricks and roof tiles is through their usage as recycled aggregate for concrete. Since the application of concrete with crushed clay bricks and roof tiles is not widespread, it is necessary to investigate the possibility of applying it in areas where such concrete shows better properties than concrete with natural aggregate. Based on literature review, concrete with crushed clay bricks and roof tiles has better thermal properties and fire resistance than ordinary concrete with natural aggregate. In dissertation is investigated the possibility of usage of crushed bricks and roof tiles in the fire resistant precast concrete roof blocks. The review of the current areas of application of concrete with crushed bricks and roof tiles as aggregate, objectives and possible constraints related to researching the usage of crushed bricks and roof tiles in new construction applications are shown. The requirements to be met in order to ensure the application of crushed clay bricks and roof tiles as concrete aggregate in new precast concrete block and beam floor systems are shown. Experimental investigations have a significant role in the area of innovative application of existing materials, improvement and development of their production process. Set goal of experimental investigation could be very complicated because of great number of variables that could have a significant impact on the results of experiment. Therefore, in dissertation is chosen a plan of experiment that comprises the most important variables, and in this way the extent of research is decreased without a risk of significant reduction of result accuracy. A preliminary experimental testing of properties of concrete components was carried out, as well as the testing of the concrete with crushed clay brick and roof tiles. Design of experiment applied to testing has been described. Selection of acceptable mixtures was carried out using experimental results and mathematical model. Selection of optimal mixture was carried out using multi-criteria optimization. Selected optimal mixtures were tested at the level of material in terms of physical-mechanical and durability properties after exposure to temperatures of 20° C, 200° C, 600° C, 800° and 1000° C. Based on the results of experimental investigation optimal mixture with the best properties in fresh and hardened state is selected with a view to the possible application in the precast concrete blocks. Experimental tests were conducted on optimal mixture at the level of structural elements – precast concrete blocks. Precast concrete blocks were made of concrete with crushed clay bricks and roof tiles. Their properties were tested at room temperature and after exposure to high temperature, in accordance with requirements of HRN EN 15037-2:2009: Precast concrete products – Beam and block floor systems – Part 2: Concrete blocks. Ultimate limit state verification of blocks was carried out before and after exposure to high temperatures. It was concluded that it is possible to produce precast concrete blocks made of concrete with crushed bricks and roof tiles as aggregate that are applicable for precast concrete block and beam roof/floor systems with improved resistance to high temperature.
Parallel keywords (Croatian)opekarski lom beton dizajn eksperimenta stropni sustavi optimizacija
ExtentV, 224 str. : graf. i tabelarni prikazi : ilustr. (u bojama) ; 30 cm
Versionaccepted version
Resource typetext
Access conditionOpen access
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
Noteaccepted version
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:133:213795
CommitterVesna Zobundžija