COMPARISON OF CROATIAN AND EUROPEAN STANDARDS FOR DETERMINING THE FROST SUSCEPTIBILITY OF HYDRAULICALLY BOUND MIXTURES

The base layer of a multi-layered pavement structure is often a cement-bound material, which combines an aggregate with cement binder. This load-bearing layer is quite rigid, which improves pavement properties, including frost resistance, and extends the life cycle of the pavement. In geographic areas with low temperatures and significant ground water, the bearing capacity of pavement structures can be reduced by volume deformations from freezing and thawing. Cold winters and frost-susceptible soil are present in eastern Croatia and in the city of Osijek. Thus, in this paper we examine the frost susceptibility of cement-bound aggregates, made with materials commonly used in Croatia, in accordance with the current Croatian standard HRN U.B1.050 and a new European standard EN 13286-54. The test mixtures did not meet the conditions for frost-resistant materials. To meet these conditions, one must use a higher cement ratio or a cement with a higher strength class

MJERE ZA SMANJENJE PROMETNE BUKE NA PRIMJERU GRADA OSIJEKA

Noise pollution is a major environmental problem in urban spaces worldwide. The first step toward noise abatement is determining and evaluating noise levels in order to best prioritize and implement protective measures. The city of Osijek, as is obligated by law and the European Directive, has done this by creating a noise map. In this paper, we present measures for noise abatement, showing some of the measures implemented in Osijek based on their noise map, and review possible methods for abating noise in the most vulnerable areas.Zagađenje bukom danas je jedan od glavnih, u svijetu prisutnih problema zagađenja okoliša i urbanog prostora. Prvi korak ka smanjenju razina buke je utvrđivanje i ocjena razina buke kako bi se mogli definirati prioriteti za provedbu mjera zaštite. Grad Osijek, budući da je dužan prema Zakonu o zaštiti od buke i Direktivi Europskog parlamenta, izradio je kartu buke koja prikazuje razine buke i njihovu prostornu distribuciju. Ovaj rad prikazuje mjere za zaštitu od buke te neke od mjera provedene u gradu Osijeku i, na osnovu stanja utvrđenog kartom buke, razmatra mogućnosti provedbe mjera za zaštitu od buke najugroženijih područja

RAZVITAK TRAMVAJSKOG PROMETA GRADA OSIJEKA

The need for the introduction of trams in Osijek in the late 19th century was largely due to the poor connectivity between the areas of the city and the growing development of the city. Tram transport was an extremely important step in connecting and modernizing the city and a key step in the integration of the still unconnected areas of the city, a role it has played throughout history. From its beginnings, the residents of Osijek have been intricately connected to the tram, which has had a role in the modernization of the city and is today regarded as a symbol of the city. As a means of public transport, in Croatia, the tram is now used only in Zagreb and Osijek. Today, many cities around the world have reintroduced trams as a public transport system, and Osijek is one of the few “small” cities that can boast of its continuous existence and expansion. This paper describes the development and current state of tram traffic in Osijek as a contribution to the celebrations of the anniversary of the introduction of the electric tram in the city.Potreba za uvođenjem tramvaja u Osijeku krajem 19. stoljeća bila je velika zbog slabe povezanosti dijelova grada i njegove sve veće razvijenosti. Pokretanje tramvajskog prijevoza bio je iznimno važan korak u povezivanju i modernizaciji grada i ključni korak u integriranju tada još nepovezanih gradskih cjelina, a tu ulogu zadržao je kroz cijelu povijest. Od samih početaka, stanovnici Osijeka su posebno vezani za tramvaj koji je imao važnu ulogu i u modernizaciji grada, a danas je tramvaj svojevrstan simbol grada. Tramvaj u javnom prometu u Hrvatskoj danas se koristi jedino u Zagrebu i Osijeku. Mnogi gradovi svijeta danas ponovo uvode tramvaje u sustav javnog prijevoza, a Osijek je među rijetkim "malim" gradovima koji se mogu pohvaliti njegovim neprekinutim postojanjem i proširenjem. U ovome radu opisan je razvoj i postojeće stanje tramvajskog prometa u Osijeku, kao prilog obilježavanju obljetnice uvođenja električnog tramvaja u Osijeku

The potential of bioash for utilization in road construction in eastern Croatia

In recent years usage of biomass as energy source has intensified in eastern Croatia. Newly built biomass power plants generate great amounts of bioash that is being disposed at landfills. Due to its favorable properties bioashes could be reused as alternative materials in road construction or road fundation. Therefore, research on application of bioashes in construction industry is being conducted at Faculty of Civil Engineering in Osijek. The main motivation behind this research, in a form of biomass and bioash production in eastern Croatia as well as international research on potential application of this types of bioashes, is show in this paper

Laboratory Evaluation of the Properties of Asphalt Mixture with Wood Ash Filler

Today, the road construction profession is more than ever facing limited and increasingly expensive resources for component materials of asphalt mixtures, which has also led to the need for continuous research on the use of waste materials. One such potentially usable waste material is ash obtained by the combustion of wood biomass that is used to produce heat and electricity. The goal of this paper is to ascertain the possibility of using wood ash (WA) as the filler in asphalt concrete mixtures for the base-wearing layers of a pavement. The properties of Marshall stability (MS), quotient (MQ) and deformations, and the indirect tensile strength of water-conditioned samples and dry samples were tested on asphalt samples of an AC16 surf mixture with different contents of wood ash as the filler. The obtained values of MS and MQ indicate that a 50% content of bio ash in the filler results in an increase in asphalt’s resistance to the appearance of plastic deformations and greater tensile strength and in good asphalt resistance to the action of water

Laboratory Evaluation of the Properties of Asphalt Mixture with Wood Ash Filler

Today, the road construction profession is more than ever facing limited and increasingly expensive resources for component materials of asphalt mixtures, which has also led to the need for continuous research on the use of waste materials. One such potentially usable waste material is ash obtained by the combustion of wood biomass that is used to produce heat and electricity. The goal of this paper is to ascertain the possibility of using wood ash (WA) as the filler in asphalt concrete mixtures for the base-wearing layers of a pavement. The properties of Marshall stability (MS), quotient (MQ) and deformations, and the indirect tensile strength of water-conditioned samples and dry samples were tested on asphalt samples of an AC16 surf mixture with different contents of wood ash as the filler. The obtained values of MS and MQ indicate that a 50% content of bio ash in the filler results in an increase in asphalt’s resistance to the appearance of plastic deformations and greater tensile strength and in good asphalt resistance to the action of water

Evaluation of Strength Properties of Sand Stabilized with Wood Fly Ash (WFA) and Cement

The article describes the laboratory evaluation of mixtures of sand modified with wood fly ash (WFA) and additionally stabilized with different amounts of cement. Laboratory research includes determining the California Bearing Ratio (CBR), compressive and indirect tensile strengths of the mixtures, and the resistance of mixtures to freezing/thawing cycles. The aim of the research is to determine if WFA, an alternative material, can improve sand bearing capacity and contribute to strength development while reducing necessary cement amounts and satisfying the technical regulation for use in pavement base courses. The test results obtained show that WFA has a considerable stabilization effect on the sand mixture and improves its load bearing capacity. By adding a small quantity of the cement, the hydraulic reaction in the stabilized mixture is more intense and results in greater strengths and an improved resistance to freezing. The test results show that, by replacement of part of the sand with WFA (in the quantity of 30%), greater strengths can be achieved in relation to the mixture of only sand and cement. Additionally, the content of cement necessary for the stabilization of sand (usually 8–12%) is considerably reduced, which enables cost savings in the construction of pavement structures

Anwendung der GIS-Technologie in Straßenunterhaltungssystemen

Geografski informacijski sustav (GIS) korisna je tehnologija za upravljanje prostornim bazama podataka koje su osnova sustava za upravljanje kolnicima. Pri kreiranju sustava za upravljanje kolnicima u GIS-u treba uzeti u obzir potrebe i dostupna sredstva pojedine uprave za ceste. U radu je prikazana uspostava jednostavnog sustava za upravljanje i vođenje baze podataka za potrebe malih gradskih uprava. Baza podataka stvorena je ručnim prikupljanjem podataka o stanju kolnika nekoliko nerazvrstanih cesta u gradu Osijeku. Na osnovi prikupljenih podataka sustav proračunava PSI indeks i uspoređuje stanje kolnika.The Geographic Information System (GIS) is a useful technology for managing spatial databases, which are the basis of the Pavement Management System. When creating a pavement management system in GIS, the needs and available resources of individual road authorities should be considered. This paper describes establishment of a simple database management system for small city administrations. The database was created by manual collection of pavement condition data at several unclassified roads in the city of Osijek. Based on collected data, the system calculates the PSI index and compares pavement condition.Das geografische Informationssystem (GIS) ist eine nützliche Technologie für die Verwaltung der räumlichen Datenbanken, welche die Grundlage des Systems des Fahrbahnmanagements bildet. Bei der Entwicklung des Fahrbahnmanagementsystems im GIS müssen auch die Anforderungen und die Verfügbarkeit der Mittel einzelner Straßenverwaltungsbehörden berücksichtigt werden. In der Abhandlung werden die Einrichtung eines einfachen Systems für das Management und die Leitung der Datenbanken für die Bedürfnisse kleinerer städtischer Behörden. Die Datenbank wurde durch manuelles Zusammentragen von Daten über den Zustand von Fahrbahnen einiger nicht kategorisierter Straßen in der Stadt Osijek erstellt. Aufgrund der zusammengetragenen Daten berechnet das System den PSI Index und vergleicht den Zustand der Fahrba

Möglichkeit der Verwendung von Bioasche beim Straßenbau

Biopepeli su neizbježan proizvod ispunjavanja zahtjeva za sve većom primjenom obnovljivih izvora u proizvodnji energije. Ekološki i ekonomski problemi zbrinjavanja biopepela, zbog prikladnih kemijskih i fizikalnih svojstava, mogu se smanjiti njegovom primjenom kao sirovine u građevinarstvu. U radu se daje pregled istraživanja mogućnosti primjene biopepela pri gradnji cesta, uzimajući u obzir velik raspon svojstava koja ga karakteriziraju ovisno o porijeklu biomase i uvjetima izgaranja. U radu je također dan pregled istraživanja biopepela nastalog kao proizvod izgaranja biomase u termoelektranama na području Republike Hrvatske.Bioashes are inevitable product of meeting the demands to satisfy the increased use of renewable resources in energy production. Ecological and economic problems of bioash disposal, due to its appropriate chemical and physical properties, can be reduced by its application in the construction industry as raw materials. The paper therefore provides an research overview on various aspects of the bioash application in road construction, in compliance with a range of properties depending on the type of biomass and the conditions of combustion. Also shown is current state of research of bioash generated in the domestic thermal power plants.Bioasche ist aufgrund der Erfüllung der Forderungen nach immer größerer Verwendung von erneuerbaren Quellen bei der Energieerzeugung ein unvermeidliches Produkt. Die ökologischen und wirtschaftlichen Probleme bei der Entsorgung von Bioasche können wegen der angemessenen chemischen und physikalischen Eigenschaften durch dessen Verwendung als Rohstoff im Bauwesen verringert werden. Die Abhandlung gibt eine Übersicht über die Untersuchungen der Möglichkeiten der Verwendung von Bioasche beim Straßenbau, unter Berücksichtigung der großen Bandbreite an Eigenschaften, die sie abhängig von der Herkunft der Bioasche und den Verbrennungsbedingungen charakterisieren. Die Abhandlung gibt auch eine Übersicht über die Untersuchungen der Bioasche, die als Produkt der Verbrennung von Biomasse in Wärmekraftwerken auf dem Gebiet der Republik Kroatien entstanden ist