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Application of eggshell powder as a partial replacement of aggregate in micro concretes and mortars
No full textRastuća proizvodnja otpada, koja je rezultat rasta stanovništva i industrije, dovodi do sve brojnijeg stvaranja odlagališta za taj otpad. Jedan od najčešćih prehrambenih otpadnih materijala je ljuska jajeta kod koje se već godinama bilježi porast potrošnje. Osim povećanja količine otpada, prisutna je i rastuća eksploatacija prirodnog agregata za građevinarstvo. S obzirom na kemijski sastav ljuske koji je vrlo sličan sastavu vapnenca, ljuska je pronašla moguću primjenu i u građevinarstvu kao zamjena za navedene prirodne materijale. U okviru ovog rada ispitana je mogućnost djelomične zamjene sitnog agregata ljuskom jajeta u mortovima i mikro betonima. Izrađene su mješavine morta i mikro betona s različitim udjelima ljuske jajeta te su ispitana njihova svojstva u svježem i očvrsnulom stanju. U svježem stanju izmjerene su konzistencija, gustoća te poroznost mješavina, dok su u očvrsnulom stanju ispitane tlačna čvrstoća te vlačna čvrstoća savijanjem. Provedena je analiza svih rezultata s ciljem utvrđivanja optimalne količine ljuske koja bi se mogla primijeniti u mješavinama morta i mikro betona, a da ujedno zadrži zadovoljavajuća svojstva u svježem i očvrsnulom stanju.The growing production of waste, which is the result of the growth of the population and industry, leads to the creation of more and more landfills for that waste. One of the most common food waste materials is eggshell, the consumption of which has been increasing for years. In addition to the increase in the amount of waste, there is also a growing exploitation of natural aggregate for construction. Given the chemical composition of the eggshell, which is very similar to the composition of limestone, the shell has found a possible application in construction as a substitute for the aforementioned natural materials. Within the framework of this work, the possibility of partially replacing fine aggregate with eggshell in mortars and micro-concretes was examined. Mixtures of mortar and micro concrete with different proportions of eggshell were made and their properties were tested in the fresh and hardened state. In the fresh state, the consistency, density and porosity of the mixtures were measured, while in the hardened state, the compressive strength and tensile strength by bending were tested. An analysis of all the results was carried out with the aim of determining the optimal amount of shell that could be applied in mortar and micro concrete mixtures, while at the same time retaining satisfactory properties in the fresh and hardened state
Damage ratio spectra for selected SDOF models and seismic accelerograms
No full textKako bi se smanjio broj ljudskih žrtava i velika materijalna šteta nakon djelovanja potresa, raste
potreba za procjenom potresne oštetljivosti postojećih građevina, ali i onih građevina koje se tek
trebaju graditi. Oštetljivost, kao jedna od tri faktora procjene rizika, predmet je istraživanja ovog
diplomskog rada. Kroz prikaz brojnih modela s jednim stupnjem slobode (engl. Single Degree of
Freedom, SDOF) s različitim osnovnim periodima konstruirani su spektri koeficijenta oštetljivosti.
Na temelju dobivenih spektara procijenjena je potresna oštetljivost odabranih stvarnih zgrada.To reduce the number of human casualties and major material damage after an earthquake, there
is a growing need to assess the earthquake vulnerability of existing buildings, as well as those
buildings that have yet to be built. Vulnerability, as one of the three components of risk assessment,
is the subject of research in this paper. Through the presentation of numerous models with a single
degree of freedom (SDOF) with different elastic periods, the damage ratio coefficient spectra will
be created. Based on the obtained spectra, the seismic vulnerability of selected real buildings will
be assessed
Baseline plan considering atmospheric influences and worker acclimatization
No full textVeliki problem građevinarstva u Republici Hrvatskoj jest odlazak kvalificirane domaće radne snage u zemlje gdje su bolji radni i životni uvjeti. To rezultira potrebom uvoza radne snage iz drugih zemalja. Jedan od glavnih problema uvoza radne snage je nekvalificiranost za obavljanje građevinskih radova i neprilagođenost klimi u RH što rezultira smanjenjem produktivnosti i
kvalitete građevinskih projekata, ali i otežanim planiranjem trenutnih i budućih projekata. Osim što strani radnici zbog svoje nestručnosti povećavaju rizik od ozljeda na gradilištu, njihova neprilagođenost klimi može rezultirati njihovim zdravstvenim problemima ako ne prate upute nadređenih i može dovesti do produljenja trajanja projekta. Uz to se javlja i problem jezične barijere i ne znanja u čitanju nacrta koji dodatno pogoršavaju čitavu sliku gradilišta. Hrvatsko građevinarstvo primorano je nositi se s karakteristikama neaklimatiziranih radnika, dugotrajnim procesom dobivanja dozvole za njihov boravak i rad i brzim odlaskom istih u druge zemlje članice Europske unije gdje su bolje plaćeni i gdje imaju bolje radne uvjete, ali i gubitkom njihove radne efikasnosti uslijed rada pri visokim temperaturama. Sve to u konačnici rezultira produljenjem trajanja projekta i povećanjem troškova što govori da možda ipak jeftina radna snaga i nije ekonomski isplativa. U ovome radu prikazan je proračun produljenja trajanja projekta u odnosu na početno, planirano, trajanje u ovisnosti o atmosferskim utjecajima i aklimatiziranosti radnika.A significant problem in the construction industry in the Republic of Croatia is the emigration of qualified domestic labor to countries with better working and living conditions. This results in the need to import labor from other countries. One of the main issues with importing labor is the lack of qualifications for performing construction work and the lack of adaptation to the climate in Croatia, which leads to decreased productivity and quality of construction projects, as well as difficulties in planning current and future projects. In addition to the fact that foreign workers, due to their lack of expertise, increase the risk of injuries on the construction site, their lack of adaptation to the climate can result in health problems if they do not follow the instructions of their superiors and can lead to project delays. Furthermore, there is the issue of language barriers and the inability to read blueprints, which further deteriorates the overall situation on the construction site. Croatian construction is forced to deal with the characteristics of non-acclimatized workers, the lengthy process of obtaining permits for their stay and work, and their quick departure to other EU member states where they are better paid and have better working conditions. Additionally, there is a loss of their work efficiency due to working in high temperatures. All of this ultimately results in project delays and increased costs, suggesting that cheap labor may not be economically viable. This paper presents the calculation of the project duration extension about the initial planned duration, depending on atmospheric influences and worker acclimatization
Management of hydro-energy potential of watershed
No full textCilj ovog rada bio je za odabrani sliv rijeke Orljave procijeniti njegov hidroenergetski potencijal te predložiti mogućnosti za iskorištavanje identificiranog neiskorištenog hidroenergetskog potencijala. Za analizu slivnog područja korišten je digitalni model terena preko kojeg su određene vododijelnice, riječnog tokovi i pripadajuća slivna područja. Nakon toga, provedeni su proračuni
različitih tipova hidroenergetskog potencijala. Za izradu prijedloga lokacije za smještaj hidroelektrane rađen je proračun potencijala duž toka primjenom različitih kriterija. Analizom je utvrđeno prikladno područje za izgradnju hidroelektrane te je dan prijedlog za iskorištavanje tog potencijala postavljanjem male protočne hidroelektrane.The aim of this paper was to assess the hydroelectric potential of the selected Orljava River basin and to propose possibilities for utilizing the identified unused hydroelectric potential. A digital terrain model was used for the analysis of the basin area, through which watersheds, river flows, and corresponding drainage areas were determined. Subsequently, calculations of various types of hydroelectric potential were conducted. To propose a location for the hydroelectric power plant, potential along the river flow was calculated using different criteria. The analysis identified a suitable area for the construction of a hydroelectric power plant, and a proposal was made to utilize this potential by installing a small run-of-river hydroelectric power plant
Stability analysis of embankment dam
No full textU okviru ovog diplomskog rada provedena su laboratorijska ispitivanja kojima se pratilo procjeđivanje kroz modele nasute brane manjeg mjerila, s ciljem analiziranja stabilnosti takvih objekata. Izgrađena su dva modela homogene brane nagiba pokosa 1:1,3 i 1:2, koristeći riječni (dravski) pijesak poznate granulacije. Svi model izgrađeni su na nepropusnoj podlozi. Za provedbu ovih ispitivanja korišten je fizikalni model HM 169 kojim se regulirala brzina punjenja rezervoara i visina gornje vode pri čemu se pratilo formiranje procjedne linije. Na temelju dobivenih podataka izrađeni su numerički modeli koristeći računalni program GeoStudio 2024.1.0. Pomoću Seep/W analize simulirano je procjeđivanje vode kroz tijelo brane kroz točno određeno vrijeme te su tako dobiveni porni tlakovi korišteni kao ulazni parametri za Slope/W analizu, kako bi se mogla analizirati stabilnost pokosa, potencijalne klizne plohe i pripadajući faktori sigurnosti. Model s nagibom pokosa 1:2, što je ujedno i preporuka za izgradnju ovakvih objekata, pokazao je izdržljivost i mogućnost da se odupre postavljenim uvjetima, dok se kod modela sa strmijim nagibom pokosa (1:1,3) javio slom. Kako bi i drugi model zadovoljio stabilnost, poduzete su dodatne mjere u vidu ojačanja modela geotekstilom te je i takva situacija modelirana u računalnom programu GeoStudio 2024.1.0.In this study, laboratory tests were conducted to monitor seepage through the small-scale embankment dam model, with the aim of analyzing the stability of such structures. Two models of homogeneous dams with slopes of 1:1.3 and 1:2 were constructed using river (Drava) sand of known grain size. All models were built on an impermeable base. The HM 169 physical model was used for these tests, regulating the reservoir filling rate and the upstream water level while monitoring the formation of the seepage line. Based on the obtained data, numerical models were created using the GeoStudio 2024.1.0 software. The Seep/W analysis simulated water seepage through the dam body over a specified period, and the resulting pore pressures were used as input parameters for the Slope/W analysis to analyze the slope stability, potential slip surfaces, and corresponding safety factors. The model with a 1:2 slope, which is recommended for the construction of such structures,
demonstrated resilience and the ability to withstand the set conditions, whereas the model with a steeper slope (1:1.3) experienced failure. To ensure the stability of the second model, additional measures were taken by reinforcing the model with geotextile, and this scenario was also modeled using the GeoStudio 2024.1.0 software
Calculation of velocities using projections of displacements
No full textOvaj završni rad sastoji se od teorijski obrađene dvije velike grane mehanike – kinematike i dinamike. Uz teorijski dio, završni rad također sadržava i dva zadatka, jedan iz područja kinematike (zadatak 1) i iz područja dinamike (zadatak 2). U prvom dijelu rada prikazan je i riješen mehanizam uz pomoću plana pomaka i vektora, dok je u drugom dijelu prikazan i riješen zadatak gibanja složenog tijela.This final paper consists of a theoretical treatment of two major branches of mechanics - kinematics and dynamics. In addition to the theoretical part, the final paper also contains two assignments, one from the area of kinematics (assignment 1) and one from the area of dynamics (assignment 2). In the first part of the paper, the mechanism is presented and solved using the displacement plan and vectors, while in the second part, the problem of the motion of a complex body is presented and solved
Shaping of creager weir
No full textNa temelju zadane teme „Oblikovanje preljeva praktičnog profila“ napisan je završni rad iz kolegija „Hidromehanika“ koji obuhvaća dvije cjeline. Prva cjelina opisuje teorijski problem prelijevanja preko preljeva praktičnog profila. U drugoj cjelini obrađeni su podaci dobiveni laboratorijskim mjerenjima te je prikazan proračun oblikovanja preljeva praktičnog profila. Na kraju rada napisan je zaključakOn the basis of the given topic "Design of a practical profile spillway", the final paper from the course "Hydromechanics" was written, which includes two units. The first unit describes the theoretical problem of overflow over a practical profile overflow. In the second part, the data obtained by laboratory measurements was processed and the calculation of the design of the
overflow of a practical profile was presented. A conclusion is written at the end of the paper
Potresno ponašanje tradicijskih zidova od nabijene zemlje s područja istočne Hrvatske
No full textAncient earthen building techniques that originated before the advent of conventional building materials have regained the attention of the scientific and broader public with the beginning of the 21 century. Research has been performed throughout
the world in the past few years. However, due to a lack of information, the Croatian earthen building fund was not widely recognised. This study was performed within the scope of the first scientific research project, which is directed at understanding the seismic behaviour of eastern Croatian rammed earth houses. In order to understand the advancements in earthen houses made worldwide, a literature review of several manuals and normative documents, as well as more than 50 research papers, was performed. Observation of existing rammed earth houses in eastern Croatia was performed, and five documented houses were presented and their layout and usage discussed, thus creating a database of eastern Croatian rammed earth houses. Key observations concern differences in granular composition between literature recommendations and eastern Croatian rammed earth houses. On the other hand, soil plasticity and compressive strength are in line with the majority of recommendations.
Knowledge gained through literature review and field observation was the valuable foundation for performing experimental analysis of rammed earth walls. Four rammed earth walls were tested in-plane by varying excitation regimes, material composition and drying periods. However, it was determined that differences did not majorly affect the load-bearing capacity of walls or structural behaviour factor. Results were further used to perform numerical model validation in ANSYS. A parametric analysis comprising 54 numerical models was performed. In total, 18 different wall systems found i traditional rammed earth houses from eastern Croatia were analysed by applying three levels of vertical stress on top of the wall. Parametric analysis showed that rammed earth walls should not be considered free-standing units, separated from other walls in the structure, since the loadbearing and seismic capacity could be overestimated. However, the flange wall length does not need to be longer than 50 % of the observed wall length. A structural behaviour factor of ca. 2.0 was determined, thus proving that values greater than
1.5 can be used for wall systems observed. Two approaches for determining response spectrum curves were followed: the current generation of Eurocode 8 and a draft of a new generation of the standard. Thus, differences between the two generations were considered in the context of rammed earth walls. Namely, according to the draft of a new generation of Eurocode 8, traditional rammed earth walls could withstand seismic activities that could be expected in eastern Croatia, but only if the shortest
return period is considered. However, the current version of Eurocode 8 yields a more negative assessment because rammed earth walls did not show adequate seismic behaviour in any of the observed cases.Drevne tehnike zemljane gradnje, nastale prije pojave konvencionalnih građevinskih materijala, ponovno su zaokupile pozornost znanstvene i šire javnosti početkom 21. stoljeća. Proteklih godina, istraživanja su provedena diljem svijeta, ali hrvatski zemljani građevinski fond nije bio prepoznat zbog nedostatka informacija. Ovo je istraživanje provedeno u sklopu prvog znanstveno-istraživačkog projekta usmjerenog na razumijevanje potresnog ponašanja kuća od nabijene zemlje s područja istočne Hrvatske. Kako bi se razumio napredak u razumijevanju istraživanja zemljanih kuća diljem svijeta, proveden je pregled literature, koji je obuhvatio nekoliko priručnika i normativnih dokumenata te više od 50 istraživačkih radova. Provedeno je istraživanje postojećih zemljanih kuća u istočnoj Hrvatskoj te je prikazano pet dokumentiranih kuća i raspravljen njihov prostorni raspored i uporaba, čime je stvorena baza podataka zemljanih kuća istočne Hrvatske. Ključna zapažanja odnose se na razlike u sastavu materijala između preporuka u literaturi i kuća od nabijene zemlje u istočnoj
Hrvatskoj. S druge strane, plastičnost i tlačna čvrstoća tla u skladu su s većinom preporuka. Saznanja stečena pregledom literature i terenskim istraživanjem bila su vrijedan temelj za provođenje eksperimentalne analize zidova od nabijene zemlje. Četiri zida ispitana su u ravnini, variranjem režima pobude, sastava materijala i razdoblja sušenja. Međutim, utvrđeno je da razlike nisu značajno utjecale na nosivost zidova niti faktor ponašanja konstrukcije. Nadalje, rezultati eksperimenta su korišteni za provođenje validacije numeričkog modela u programu ANSYS. Provedena je parametarska analiza koja se sastoji od 54 numerička modela. Analizirano je ukupno 18 različitih zidnih sustava koji se mogu naći u tradicionalnim kućama od nabijene zemlje istočne Hrvatske, primjenom tri razine vertikalnog naprezanja na vrhu zida. Parametarska analiza je pokazala da se zidovi od nabijene zemlje ne bi trebali smatrati samostojećim jedinicama, odvojenim od ostalih zidova u konstrukciji jer bi nosivost i potresna otpornost mogla biti precijenjena. Međutim, duljina poprečnih zidova ne mora biti duža od 50 % duljine promatranog zida. Određen je faktor ponašanja konstrukcije u iznosu 2.0, čime je za promatrane zidne sustave dokazano da se mogu koristiti vrijednosti veće od 1.5. Primijenjena su dva pristupa za određivanje krivulja spektra odziva: trenutna generacija Eurokoda 8 te nacrt nove generacije norme. Stoga su razmotrane razlike u dvije generacije normi, u kontekstu zidova od nabijene zemlje. Naime, prema nacrtu nove generacije Eurokoda 8, očekuje se
da bi tradicionalni zidovi od nabijene zemlje mogli izdržati intenzitet potresne aktivnosti koje se mogu očekivati u istočnoj Hrvatskoj, ali samo uz najkraći povratni period. Međutim, trenutna generacija Eurokoda 8 daje negativniju procjenu, budući
da zidovi od nabijene zemlje nemaju zadovoljavajuće potresno ponašanje u nijednom promatranom slučaju
Consumption of timber when covering a roof with different dimensions of roof tiles
No full textTijekom pandemije COVID-19 došlo je do naglog porasta cijena što je utjecalo na svakidašnji život i životne navike. Cijene građevinskog materijala i nakon završetka pandemije nastavile su rasti te se danas investitori češće odlučuju na kupovinu obiteljske kuće ili stana kako bi uštedjeli jer je gradnja obiteljske kuće vrlo skupa. Jedan od skupljih elemenata pri izgradnji kuće jest krov. U radu su opisani pojmovi vezani za krovnu konstrukciju i krovne pokrove. Također, detaljno su opisani glineni crjepovi koji su uzeti kao primjer za usporedbu utroška drvne građe za izvedbu krovne konstrukcije s obzirom na dimenziju crijepa i kako potrošnja crijepa i drvne građe utječe na ukupnu cijenu izvođenja krova. Dani su primjeri utroška drvne građe na krovu gdje se postavlja Glinex crijep ili Cezar crijep na obiteljskoj kući čija je ukupna površina krovne plohe 115,40 m .During the COVID-19 pandemic, there was a sudden increase in prices, which affected everyday life and lifestyle. The prices of construction materials continued to rise even after the end of the pandemic, and today investors more often decide to buy a family house or apartment in order to save money, because the construction of a family house is very expensive. One of the more expensive elements when building a house is the roof. The paper describes terms related to roof construction and roof coverings. Also, clay tiles are described in detail, which were taken as an example for comparing the consumption of timber for the construction of the roof structure with regard to the size of the tiles and how the consumption of tiles and timber affects the total cost of the roof construction. Examples are given of the consumption of timber on the roof where Glinex tiles or Caesar tiles are installed on a family house with a total roof area of 115.40 m
Project control methods
No full textU ovom diplomskom radu bilo je potrebno analizirati i opisati metode kontrole projekata u fazi izvršenja. Potrebno je primijeniti odabranu metodu kroz kontrolu troškova, vremena i tehničku izvedbu zadanog projekata. Nakon provedene analize odnosa planiranih, stvarnih i ostvarenih vrijednosti potrebno je komentirati indekse izvršenja. U prvom poglavlju objašnjen je pojam građevinskog projekta i koje su preporuke za skraćivanje prekoračenja izvedbe projekata. U drugom poglavlju opisan je sustav kontrole izvedbe projekata te objašnjena je kontrola vremena, troškova, kvalitete i njihove međusobne integracije. Zatim su opisane metode koje se koriste u kontroli izvršenja projekata kao što su EVA metoda, WBS, OBS i S - krivulja. Nakon toga definirano je upravljanje projektima koje obuhvaća planiranje, upravljanje i kontrolu. U sklopu upravljanja projektom navedena su i objašnjena projektna područja upravljanja projektom. Zaključno poglavlje sadrži prikaz primjene metode kontrole projekata na konkretnom projektu obnove građevine u Petrinji.In this thesis, it was necessary to analyze and describe the methods of project control in the execution phase. It is necessary to apply the selected method through control of costs, time and technical performance of the given project. After the analysis of the relationship between planned, actual and realized values, it is necessary to comment on the execution indices. In the first chapter, the construction project itself is explained and what are the recommendations for shortening project overruns. The second chapter describes the project performance control system and explains the control of time, costs, quality and their mutual integration. Then the methods used in project execution control are described, such as the EVA method, WBS, OBS and S-curve. After that, project management was defined, which includes planning, management and control. As part of project management, the project areas of project management are listed and explained. The last chapter contains a escription of the application of the project control method on the specific building renovation project in Petrinja