87 research outputs found
TRAFFIC CALMING IN THE CITIES
Koncept „smirivanja prometa“ temelji se na zahtjevu povećanja sigurnosti prometa, a postiže se
smanjivanjem brzine kretanja vozila u stambenim zonama i u blizini škola i dječjih vrtića te poboljšanju
preglednosti. Smirivanjem prometa moguće je postići i povećanje udobnosti i sigurnosti kod pješaka te smanjenje
neposrednih štetnih utjecaja na okoliš: smanjenje razine buke i onečišćenja zraka. Za postizanje postavljenog
cilja treba provesti čitav niz postupaka koji se sastoje od preuređenja postojeće cestovne mreže, postavljanja
posebne opreme i signalizacije za smirivanje prometa te uvođenja dosljedne i učinkovite regulative. U članku su
prikazane različite mjere smirivanja prometa uvažavajući europska i domaća iskustva te dan osvrt na hrvatsku
zakonsku i tehničku regulativu iz ovog područja.The concept of "traffic calming" is based on a request to increase traffic safety which is achieved by
reducing the speed of vehicles in residential zones and near schools and kindergartens, and improving
visibility.Traffic calming can also improve the comfort and safety for pedestrians and reduce the negative impact
on the environment: reducing noise and air pollution. Achieving expected goals requires a series of procedures
that comprise the refurbishment of the existing road network, installation of special equipment and signs for traffic
calming and the introduction of consistent and effective regulation. The article presents various traffic calming
measures respecting European and domestic experiences and describes the Croatian legal and technical
regulations in this area
PRONOS ZAGAĐENJA PROCJEDNIM VODAMA IZ KOLNIČKIH KONSTRUKCIJA S LETEĆIM PEPELOM
Water is an ideal solvent; some products placed on or in the soil will eventually end up in the groundwater. Seepage water from road construction can contain
significant quantity of noxious substances that are transported from aquifers. The paper presents transport of pollutants in seepage water from pavement
structure with inbuilt fly ash. Substances from fly ash can have a noxious impact on the surrounding air, soil, and water. Depending on the concentration of
noxious substances in seepage waters, drainage can be carried out by two methods. Seepage water with a critical concentration of noxious substances is drained
through the sewage system and treated. Another method is used in case of small concentrations, which can be disintegrated by means of natural purification
processes in the soil, with seepage water discharged into the surrounding soil or waterway. Continual quality control of both seepage water and surface water
and groundwater is necessary. If fly ash of good quality is inbuilt in pavement structure (in the right proportion), it doesn't have an adverse impact on the
neighbouring air, soil, and water.Voda kao idealno otapalo pronosi različite suspendirane i otopljene tvari s površinskih u podzemne slojeve. Procjedne vode iz kolničke konstrukcije mogu
sadržavati značajne količine štetnih tvari koje se dalje pronose kroz vodonosne slojeve. U radu je opisan pronos zagađenja procjednih voda iz kolničke
konstrukcije u koju je ugrađen leteći pepeo, a koji zbog svog sastava može imati štetan utjecaj na okolni zrak, tlo i vodu. Ovisno o koncentraciji štetnih tvari u
procjednim vodama njihova odvodnja se može izvesti na dva načina. Kod kritičnih koncentracija štetnih tvari u procjednim vodama one se odvode sustavom
kanalizacije i pročišćavaju, dok kod malih koncentracija, koje se mogu razgraditi putem samopročišćavanja kroz procese u tlu, procjedne se vode mogu
upustiti u okolno tlo ili vodotok. Potrebna je stalna kontrola kvalitete kako procjednih tako i površinskih i podzemnih voda. Dosadašnja istraživanja i rezultati
pokazali su da, iako postoji opasnost od mogućeg štetnog utjecaja letećeg pepela iz kolničke konstrukcije na okoliš, ukoliko se pepeo ugradi kvalitetno i u
pravom omjeru ne predstavlja opasnost po okolno tlo, zrak i vodu
Compressive strenght of steel slag stabilized mixes
U radu su opisana ispitivanja tlačnih čvrstoća stabilizacijskih mješavina sa zgurom iz željezare Sisak i ’’standardnih’’ stabilizacijskih mješavina s drobljenim kamenim agregatom iz kamenoloma ’’Velika”. Ispitivanjem se nastojalo utvrditi pogodnost zgure kao agregata u nosivim slojevima kolničkih konstrukcija te utjecaj udjela veziva i granulometrijskog sastava stabilizacijskih mješavina na tlačne čvrstoće. Rezultati tlačnih čvrstoća dobivenih ispitivanjem zadovoljili su stroge kriterije postavljene tehničkim propisima te potvrdile mogućnost primjene zgure u stabiliziranim nosivim slojevima kolničkih konstrukcija.The compressive strength testing, conducted on stabilisation mixes with steel-furnace slag originating from the Sisak Ironworks, and on ”standard” stabilisation mixes with crushed stone aggregate from ”Velika” Quarry, is presented in the paper. The testing was made to check whether slag can be used as aggregate in pavement base courses, and to determine in what way compressive strength values are influenced by binder content and grading of stabilisation mixes. Compressive strength results obtained during this testing comply with stringent criteria set in technical regulations, and confirm that slag can be used in stabilized base courses of pavement structures
DRUCKFESTIGKEIT VON STABILISIERUNGSMISCHUNGEN AUS STAHLSCHLACKE
U radu su opisana ispitivanja tlačnih čvrstoća stabilizacijskih mješavina sa zgurom
iz željezare Sisak i ’’standardnih’’ stabilizacijskih mješavina s drobljenim kamenim
agregatom iz kamenoloma ’’Velika”. Ispitivanjem se nastojalo utvrditi pogodnost
zgure kao agregata u nosivim slojevima kolničkih konstrukcija te utjecaj udjela veziva
i granulometrijskog sastava stabilizacijskih mješavina na tlačne čvrstoće. Rezultati
tlačnih čvrstoća dobivenih ispitivanjem zadovoljili su stroge kriterije postavljene
tehničkim propisima te potvrdile mogućnost primjene zgure u stabiliziranim nosivim
slojevima kolničkih konstrukcija.The compressive strength testing, conducted on stabilisation mixes with steel-furnace
slag originating from the Sisak Ironworks, and on ”standard” stabilisation mixes with
crushed stone aggregate from ”Velika” Quarry, is presented in the paper. The testing
was made to check whether slag can be used as aggregate in pavement base courses,
and to determine in what way compressive strength values are influenced by binder
content and grading of stabilisation mixes. Compressive strength results obtained
during this testing comply with stringent criteria set in technical regulations, and
confirm that slag can be used in stabilized base courses of pavement structures.In der Arbeit wird die Prüfung der Druckfestigkeit von Stabilisierungsmischungen aus
Stahlschlacke aus der Werft Sisak und „standardmäßige” Stabilisierungsmechanismen
mit gebrochenem Zuschlag aus dem Steinbruch ”Velika” beschrieben. Bei der
Prüfung, die zufriedenstellend ausgefallen ist, war man bestrebt, die Eignung der
Schlacke als Zuschlag in den Tragschichten von Fahrbahnkonstruktionen sowie
den Einfluss des Bindemittels und der granulometrischen Zusammensetzung der
Stabilisierungsmischungen auf die Druckfestigkeit festzustellen
VERWENDUNG VON REZYKLIERTEN GESTEINSKÖRNUNGEN IN ASPHALTMISCHUNGEN
U radu su opisana ispitivanja mogućnosti primjene recikliranog asfalta u proizvodnji
asfaltnih mješavina. Ispitivanjima u laboratoriju istražena je pogodnost za primjenu
recikliranog asfalta te projektiran sastav asfaltnih mješavina BNHS-22 s 10%, 15% i 20%
recikliranog asfalta nakon čega je izvedena pokusna proizvodnja projektiranih asfaltnih
mješavina. Dobiveni rezultati omogućili su donošenje zaključaka o primjenjivosti i
potrebnom udjelu recikliranog asfalta, tehnologiji proizvodnje te mogućim uštedama
u proizvodnji novih asfaltnih mješavina.Possibilities for using recycled asphalt in the asphalt mix manufacturing process are
described in the paper. The applicability of recycled asphalt was tested in laboratory, and
asphalt mixes BNHS-22 containing 10 %, 15 % and 20 % of recycled asphalt were designed.
The trial production of asphalt mixes designed in this way was then operated. The results
obtained have lead to conclusions about the applicability and necessary proportion of
recycled asphalt, manufacturing technology, and possible savings in the manufacture of
new asphalt mixes.In der vorliegenden Arbeit ist die mögliche Anwendung von rezykliertem Asphalt in
der Herstellung von Asphaltmischungen erforscht. Durch experimentelle Versuche in
Laborbedingungen ist die Eignung von rezykliertem Asphalt für Asphaltmischungen
untersucht und die Zusammensetzung von BNHS-22 Mischungen mit 10 %, 15 % und 20
% rezykliertem Asphalt entworfen worden. Anschließend ist eine Versuchsherstellung
der zusammengestellten Asphaltmischungen durchgeführt worden. Die erhaltenen
Ergebnisse haben Schlussfolgerungen bezüglich der Verwendbarkeit von rezykliertem
Asphalt, der erforderlichen Mischungsanteile, der Fertigungstechnik und der möglichen
Einsparungen im Herstellungsprozess von neuen Asphaltmischungen ermöglicht
Transport of pollutants in seepage water from pavement structures with inbuilt fly ash
Voda kao idealno otapalo pronosi različite suspendirane i otopljene tvari s površinskih u podzemne slojeve. Procjedne vode iz kolničke konstrukcije mogu sadržavati značajne količine štetnih tvari koje se dalje pronose kroz vodonosne slojeve. U radu je opisan pronos zagađenja procjednih voda iz kolničke konstrukcije u koju je ugrađen leteći pepeo, a koji zbog svog sastava može imati štetan utjecaj na okolni zrak, tlo i vodu. Ovisno o koncentraciji štetnih tvari u procjednim vodama njihova odvodnja se može izvesti na dva načina. Kod kritičnih koncentracija štetnih tvari u procjednim vodama one se odvode sustavom kanalizacije i pročišćavaju, dok kod malih koncentracija, koje se mogu razgraditi putem samopročišćavanja kroz procese u tlu, procjedne se vode mogu upustiti u okolno tlo ili vodotok. Potrebna je stalna kontrola kvalitete kako procjednih tako i površinskih i podzemnih voda. Dosadašnja istraživanja i rezultati pokazali su da, iako postoji opasnost od mogućeg štetnog utjecaja letećeg pepela iz kolničke konstrukcije na okoliš, ukoliko se pepeo ugradi kvalitetno i u pravom omjeru ne predstavlja opasnost po okolno tlo, zrak i vodu.Water is an ideal solvent; some products placed on or in the soil will eventually end up in the groundwater. Seepage water from road construction can contain significant quantity of noxious substances that are transported from aquifers. The paper presents transport of pollutants in seepage water from pavement structure with inbuilt fly ash. Substances from fly ash can have a noxious impact on the surrounding air, soil, and water. Depending on the concentration of noxious substances in seepage waters, drainage can be carried out by two methods. Seepage water with a critical concentration of noxious substances is drained through the sewage system and treated. Another method is used in case of small concentrations, which can be disintegrated by means of natural purification processes in the soil, with seepage water discharged into the surrounding soil or waterway. Continual quality control of both seepage water and surface water and groundwater is necessary. If fly ash of good quality is inbuilt in pavement structure (in the right proportion), it doesn\u27t have an adverse impact on the neighboring air, soil, and water
UTJECAJ GEOMREŽA NA SVOJSTVA TLA
As a part of the research project in progress at the Civil Engineering Faculty in Osijek a new large pullout testing device has been developed and
specially instrumented for characterisation of interaction between soil and geosynthetic in a pullout box by measuring wave velocity in the soil
around the geosynthetic, before and at stops during pullout procedure. This paper presents some of the results of investigation carried out on one
geogrid in one type of gravel, in terms of modulus of elasticity E and shear modulus G developed in the soil around the geogrid, under different
vertical stresses and different grid displacements. The results presented are part of a wider range of testing results in the project. When state after
compaction was tested, significant influence of the grid on E and G values compared to non-reinforced soil was not clearly detected. It is expected
that after some displacement of geogrid during pullout process, E and G values for reinforced and non-reinforced soil will be significantly
different. Examining this is the next step in the research programme.Za potrebe ispitivanja interakcije tla i geosintetika, u okviru znanstvenog projekta istraživanja učinkovitosti armature na Građevinskom fakultetu
u Osijeku, razvijen je posebno instrumentirani veliki uređaj za izvlačenje "pullout box" pomoću kojeg je moguće mjeriti brzinu valova u tlu u blizini
geosintetika, prije početka i u prekidima ispitivanja. Ovaj rad iznosi samo dio rezultata ispitivanja modula elastičnosti E i modula posmika G
koji nastaju u tlu oko geomreže, a koji su dio rezultata opsežnijih istraživanja u okviru spomenutog projekta. Predstavljena su ispitivanja na jednom
tipu geomreže u šljunku jedne granulacije pri različitim vertikalnim naprezanjima i pomacima mreže. Kod ispitivanja u zbijenom stanju nije
bio jasno uočljiv utjecaj mreže na vrijednosti E i G modula u odnosu na tlo bez mreže. Po ostvarivanju određenog pomaka geomreže za očekivati
je da će vrijednosti E i G modula za armirano i nearmirano tlo biti bitno drugačije. Istraživanje ove pretpostavke je sljedeći korak u programu ispitivanja
STRENGTH PROPERTIES OF FLY ASH STABILIZED MIXES
A laboratory investigation of the properties of cement-stabilized pavement base
course materials consisting of sand from the river Drava stabilized by hydraulic binder made
of cement and fly ash is presented. The goal of the investigation was to determine the
influence of several factors on the compressive and indirect tensile strengths. The factors
included: a change in the structure of the stabilized mixes, a change in the treatment
temperature and the time used in the sample treatment. The hydraulic binder was prepared
using different percentages of fly ash in the binder: 0% (control mix), 25%, 50%, and 75%. It
was determined that the amount of fly ash strongly influences the strength of the stabilized
mixes. Increasing the amount of fly ash in the binder leads to a decrease in the compressive
and indirect tensile strengths
KARAKTERIZACIJA CEMENTOM STABILIZIRANIH NOSIVIH SLOJEVA KOLNIČKIH KONSTRUKCIJA METODOM ULTRAZVUKA
Performance of ultrasonic pulse velocity (UPV) in hydraulically bound mixtures is examined as a non-destructive testing, in order to estimate its potential for pavement material characterization. Test results show that an increase in cement content results in an increase in UPV values. Increase in steel slag aggregate content results in a decrease in UPV values. Analyses of relationship between UPV values and strengths have shown strong polynomial relationship. For UPV values ranging 2 ÷ 3,2 km/s cement stabilized material can be classified as appropriate for usage in road construction. Test results have shown good potential for UPV measure as non-destructive method in cement stabilized material characterization.U radu je ispitana mogućnost primjena metode mjerenja brzine ultrazvučnog impulsa kao nerazorne metode pri karakterizaciji hidraulički vezanih materijala kolničkih konstrukcija. Rezultati ispitivanja su pokazali da povećanje količine cementa rezultira povećanjem vrijednosti brzine ultrazvuka. Povećanje udjela čeličanske zgure u agregatu rezultira smanjenjem vrijednosti brzine ultrazvuka. Analiza odnosa brzine ultrazvuka i čvrstoće materijala pokazala je jaku polinomnu vezu. Za vrijednosti brzine ultrazvuka u rasponu od 2 ÷ 3,2 km/s cementom stabilizirani materijal može biti klasificiran kao prikladan za uporabu u cestogradnji. Rezultati ispitivanja pokazali su moguću uporabu metode mjerenja ultrazvuka kao nerazorne metode pri
karakterizaciji cementom stabiliziranih materijala kolničke konstrukcije
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