Criteria for longitudinal evenness of asphalt-pavement driving surfaces

U cilju sagledavanja utjecaja opsega građevinskog zahvata i klase javnih cesta, u radu su opisani čimbenici koji utječu na postizanje ravnosti asfaltnih voznih površina. Statistički su analizirane vrijednosti indeksa ravnosti IRI100, izmjerene na, u posljednje četiri godine, izvedenim kolnicima hrvatske cestovne mreže. Utvrđeni su granični kriteriji ravnosti vozne površine za tri glavne klase cesta (autoceste; državne ceste; gradske ceste) te sedam kategorija asfaltnih kolnika.In order to define the influence of the scope of construction work and public road categories, the authors define factors that are significant for achieving evenness of asphalt-pavement driving surfaces. The values of international roughness index IRI100, measured on pavements built over the past four years on the Croatian road network, are analyzed statistically. Limit criteria for road pavement surfaces are defined for three principal road categories (motorways, national roads, and municipal roads) and seven asphalt pavement categories

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

ЦЕМЕНТНАЯ СТАБИЛИЗАЦИЯ : ХАРАКТЕРИЗОВАНИЕ МАТЕРИАЛОВ И ПРОЕКТНЫЕ КРИТЕРИИ

U radu su prikazane metode određivanja Youngovog modula elastičnosti i Poissonovog omjera cementom stabiliziranih materijala kao osnovnih svojstava za karakterizaciju materijala. Pregledom dosadašnjih istraživanja prikazani su projektni kriteriji ovih slojeva kolničke konstrukcije. Razmatran je i umor materijala kao projektni kriterij te projektni kriteriji novih, recikliranih materijala čiji utjecaj na svojstva ovih slojeva kolničke konstrukcije nije potpuno istražen.Methods for determining the Young's modulus of elasticity and the Poisson ratio, taken as basic properties for characterization of cement-stabilized materials, are presented in the paper. In the scope of presentation of studies conducted so far, design criteria are given for these layers of the pavement structure. The fatigue of materials is also considered as a design criterion, and design criteria are offered for new recycled materials whose influence on properties of these pavement-structure layers has not been fully investigated.Im Artikel beschreibt man die Methoden der Festlegung Young,s Elastizitätmoduls und Poisson,s Koeffizients von zementstabilisierten Materialen als grundlegende Kennzeichen für die Charakterisierung des Materials. Durch Übersicht der bisherigen Untersuchungen sind Projektkriterien dieser Fahrbahnschichten dargestellt. Man erwägte auch die Materialermüdung als Projektkriterium sowie Projektkriterien neuer, rezyklierter Materiale deren Einfluss auf die Kennzeichen dieser Fahrbahnschichten nicht vollständig erforscht ist.Les méthodes pour la détermination du module d'Young et du coefficient de Poisson, comme propriétés de base pour la caractérisation des matériaux stabilisés au ciment, sont présentées dans l'ouvrage. Au cours de présentation des études conduites jusqu'à présent, les critères pour l'étude de ces couches de chaussée sont fournis. La fatigue de matériaux est aussi considérée comme un critère d'étude, et les critères d'étude sont également fournis pour les nouveau matériaux recyclés dont l'effet sur propriétés de ces couches de chaussée n'a pas encore été pleinement étudié.В работе приведены методы определения модуля упругости Юнга и коэффициента Пуассона для материалов, стабилизованных цементом, в качестве основных свойств характеризации материалов. На основе обзора исследований, проведенных до настоящего времени, приведены проектные критерии для слоев дорожной одежды. В качестве проектного критерия рассмотрено уставание материала, а также проектные критерии для новых, рециклированных материалов, влияние которых на свойства слоев дорожной одежды еще полностью не исследовано

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

SPURRINNENBESTÄNDIGKEIT DES WASSERABDICHTUNGS : UND ASPHALTBELAGSYSTEMS VON BRÜCKEN

Na voznim površinama mostova pri primjeni klasičnih sustava hidroizolacije s tankim asfaltnim slojevima učestalo se pojavljaju plastične deformacije, posebice one oblika kolotraga. U okviru istraživanja provedena je analiza postojećih sustava u eksploataciji, laboratorijska ispitivanja i terenska mjerenja relevantnih svojstava pojedinih elemenata sustava, kao i sustava u cjelini, koji utječu na otpornost pojave kolotraga. Dobiveni rezultati su provjereni i potvrđeni na primjenjenom sustavu hidroizolacija – asfaltni kolnik pri izgradnji vijadukta Odra na autocesti A11.Application of traditional waterproofing systems with thin asphalt courses results in occurrence of plastic deformities on traffic areas of bridges, especially in the form of rutting. The investigations comprised the analysis of the existing systems in exploitation, laboratory testing and on site measurements of relevant properties of individual system elements, as well as the system as whole, which have an impact to the resistance to rutting. The achieved results were controlled and confirmed on the waterproofing – asphalt courses system executed during construction of the Odra viaduct on the A11 motorway.Die Anwendung traditioneller Wasserabdichtungssysteme mit dünnen Asphaltschichten führt zum Auftreten plastischer Verformungen in Verkehrsbereichen von Brücken, insbesondere in der Form von Spurrinnen. Die Untersuchungen in dieser Arbeit umfassen Analysen bestehender Systeme in Betrieb, experimentelle Versuche und, sowohl für individuelle Systemelemente als auch für ganze Systeme, Messungen vor Ort der relevanten Eigenschaften, die Einfluss auf die Spurrinnenbeständigkeit haben. Die erhaltenen Resultate sind im Laufe der Erbauung des Odra Viadukts auf der Autobahn A11 anhand des entsprechenden Wasserabdichtungs- und Asphaltbelagsystems kontrolliert und bestätigt worden

Inuence of Pressure on Water Permeability and Characteristic Opening Size of Nonwoven Geotextiles

Nonwoven geotextiles manufactured by mechanical carding process and bonding by needling process are investigated in this paper. Part of the samples was additionally bonded by thermal calendaring process. Sampling was conducted according to the standard for geotextile with certain modications. The samples were tested for water permeability perpendicular to the plane of samples using loads of 2, 20 and 200 kPa. Characteristic opening size of geotextiles was tested using sieving method. Research shows that dierent applied pressures signicantly change structure and properties i.e. thickness and water permeability normal to the plain under load of geotextile

EIGENSCHAFTEN VON MISCHUNGEN MIT RECYKLIERTEM ASPHALT ZUR AUSFÜHRUNG UNABHÄNGIGER TRAGSCHICHTEN

U radu je istražena mogućnost primjene recikliranog asfalta kao zamjene za prirodni agregat u mješavinama za izradu nevezanih nosivih slojeva. Istraživanje je provedeno na mješavinama u kojima je određeni udio prirodnog agregata (vapnenca, šljunka) zamijenjen recikliranim asfaltom. Programom istraživanja obuhvaćena su ispitivanja granulometrijskog sastava, parametara zbijanja, fizikalno-mehaničkih svojstava i nosivosti mješavina. Rezultati pokazuju da reciklirani asfalt, u određenom udjelu, može biti prikladna zamjena za prirodni agregat.The possibility of using recycled asphalt as replacement for natural aggregate in unbound base course mixes is explored in the paper. The mixes in which a certain proportion of natural aggregate (limestone, gravel) was replaced with recycled asphalt were analysed. The testing program involved analysis of the grading, compaction parameters, physicomechanical properties and bearing capacity of mixes. The results show that recycled asphalt can be used, in some proportions, as a suitable replacement for natural aggregate.In dieser Arbeit wird die mögliche Anwendung recykierten Asphalts als Ersatz für natürliche Gesteinskörnung in Mischungen zur Ausführung unabhängiger Tragschichten erforscht. Die Untersuchungen wurden an Mischungen durchgeführt, bei denen ein Anteil natürlicher Gesteinskörnung (Kalkstein, Kies) mit recykliertem Asphalt ersetzt wurde. Das Forschungsprogramm umfasste die Ermittlung der granulometrischen Zusammensetzung, der Verdichtungsparameter sowie der physikalisch-mechanischen Eigenschaften und der Tragfähigkeit der Mischungen. Aufgrund der Resultate zeigt sich, dass rezyklierter Asphalt in bestimmtem Anteil als angemessener Ersatz für natürliche Gesteinskörnung angesehen werden kann

USPOREDNO ISPITIVANJE SADRŽAJA NAFTALENA U GORIVU ZA MLAZNE MOTORE HPLC I UV METODAMA

Kvantitativni podatak o sadržaju aromatskih ugljikovodika važan je za razumijevanje utjecaja pojedinog tehnološkog procesa u preradi nafte na proizvodnju različitih komercijalnih tekućih naftnih goriva, a poznavanjem sastava aromata moguće je predvidjeti kvalitetu i ekološku prihvatljivost određenog naftnog proizvoda. Naftaleni su di-aromatska skupina ugljikovodika koja, za razliku od mono-aromata, jako doprinosi dimljenju i čađenju goriva za mlazne motore te se stoga njihov sadržaj redovito prati. U radu je prikazano poboljšanje postojećeg postupka ispitivanja naftalena u gorivima za mlazne motore suvremenom standardnom analitičkom tehnikom. Izvedeno je usporedno ispitivanje sadržaja naftalena u uzorcima goriva UV spektrofotometrijom koju propisuje INA norma i tekućinskom kromatografijom visoke djelotvornosti (HPLC) te su izračunati testovi signifikantnosti. Eksperimentalnim i računskim ispitivanjima ustanovljeno je da su dobiveni rezultati usporedivi

Analysis of completely connected pavement structures

Analizirane su deformacije i naprezanja od prometnog opterećenja u potpuno vezanim kolničkim konstrukcijama. Analiza je rađena uz tri promjenjiva parametra (geometrija konstrukcije, svojstva materijala, nosivost tla). Deformacije i naprezanja uspoređeni su s onima koja se javljaju kod uobičajenih kolničkih konstrukcija. U analizama je upotrijebljen računalni program BISAR. Potpuno vezane kolničke konstrukcije pokazale su se povoljnijima u pogledu deformacija od uobičajenih.The stress and strain values generated by traffic operated on completely connected pavements structures are analyzed. The analysis is made with three variable parameters (geometry of structure, properties of materials, and load bearing capacity of soil). Stress and strain values are compared with those occurring in usual pavement structures. The computer program BISAR is used in the analyses. Completely connected pavement structures have proven to be more resistant to strain that usual pavement structures

Sexually transmitted diseases as a risk for acquiring HIV infection among the population of men who have sex with men - A Case Control Study

At the beginning of the 1980-ies, HIV infection and AIDS were described for the first time, this among the population of men who have sex with other men. Nearly thirty years later, the MSM population is still a population under heightened risk for acquiring HIV infection and other sexually transmitted diseases. This study investigates sexually transmitted diseases as a risk for HIV infection. A total of 296 men who have sex with men (MSM) were included in this case control study. Differences among the frequencies of sexually transmitted diseases among the MSM of HIV positive and HIV negative status were tested. The history of HIV positive more often states falling ill with sexually transmitted diseases than this was the case before they became HIV positive, unlike those MSM who are not HIV infected (45,9% : 11,1% that is OR 6,79, 95% CI 3,49-13,19). Hepatitis B infection is more frequent in HIV positive MSM (11,5% : 1,9%; OR 6,58, 95%CI 1,86-23,3). The frequency of gonorrhea in case history of HIV positive MSM is significantly higher than in the HIV negative group (11,5% : 3,8%, OR 3,24 , 95%CI 1,13-9,34). In the group of HIV positive MSM, unlike the HIV negative group, syphilis (14,8 : 1,0%, OR 17,74 , 95%CI 3,43-122,87) and genital herpes (8,2% : 0,5%, OR 18,39 , 95%CI 2,03-424,7) are more frequent . The results of this study will be used in future preventive activities focused on the population of MSM, as a population under particular risk for acquiring sexually transmitted infections