Marina Poposka, Borjan Petreski, Petar Cvetanovski, Denis Popovski
This article presents the advantages of using preloaded bolts in connections of steel structures. First we discussed the main differences between preloaded bolts and shear bolts. Then we explained the categories of shear connections and the categories of friction surfaces, along with their associated surface preparation and slip factor. To connect theory and codes with experiment, we showed the basic expressions used to calculate the design resistance of preloaded bolts and compared the design resistance of shear bolts. The slip factor was tested according to EN 1090-2:2008, Annex G, for two series of specimens, identical to those used in bridges in the Republic of Albania.
{"title":"EXPERIMENTAL PROCEDURE FOR SLIP FACTOR DETERMINING AT CONNECTIONS WITH PRELOADED BOLTS","authors":"Marina Poposka, Borjan Petreski, Petar Cvetanovski, Denis Popovski","doi":"10.13167/2014.8.5","DOIUrl":"https://doi.org/10.13167/2014.8.5","url":null,"abstract":"This article presents the advantages of using preloaded bolts in connections of steel structures. First we discussed the main differences between preloaded bolts and shear bolts. Then we explained the categories of shear connections and the categories of friction surfaces, along with their associated surface preparation and slip factor. To connect theory and codes with experiment, we showed the basic expressions used to calculate the design resistance of preloaded bolts and compared the design resistance of shear bolts. The slip factor was tested according to EN 1090-2:2008, Annex G, for two series of specimens, identical to those used in bridges in the Republic of Albania.","PeriodicalId":53887,"journal":{"name":"Electronic Journal of the Faculty of Civil Engineering Osijek-e-GFOS","volume":"5 1","pages":"37-43"},"PeriodicalIF":0.2,"publicationDate":"2014-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66265959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tunnels pose many fire risks. It is difficult to fight fires in tunnels due to their limited accessibility, the quantity of smoke, and high thermal radiation. Temperatures in tunnel fires can reach 1000 °C, and these fires can spread quickly and persist for long periods, the longest recorded in Europe lasting 53 h. The main requirements of tunnel pavement structures are driving safety and comfort, as well as low construction and maintenance costs. Choosing between using concrete or asphalt pavement structures in tunnels requires the assessment of many criteria, including safety, cost, ecology, and energy use. One must also consider the availability of technologies (finishers) and resources (bitumen or cement), as well as the probability of achieving the required contractor experience level, which impacts pavement management. This paper describes our analysis and process for deciding the pavement structure to be used in tunnels, as well as current European technical regulations for safe traffic flow in tunnels.
{"title":"Comparison of pavement structures in tunnels","authors":"Ivan Rimac, M. Šimun, S. Dimter","doi":"10.13167/2014.8.2","DOIUrl":"https://doi.org/10.13167/2014.8.2","url":null,"abstract":"Tunnels pose many fire risks. It is difficult to fight fires in tunnels due to their limited accessibility, the quantity of smoke, and high thermal radiation. Temperatures in tunnel fires can reach 1000 °C, and these fires can spread quickly and persist for long periods, the longest recorded in Europe lasting 53 h. The main requirements of tunnel pavement structures are driving safety and comfort, as well as low construction and maintenance costs. Choosing between using concrete or asphalt pavement structures in tunnels requires the assessment of many criteria, including safety, cost, ecology, and energy use. One must also consider the availability of technologies (finishers) and resources (bitumen or cement), as well as the probability of achieving the required contractor experience level, which impacts pavement management. This paper describes our analysis and process for deciding the pavement structure to be used in tunnels, as well as current European technical regulations for safe traffic flow in tunnels.","PeriodicalId":53887,"journal":{"name":"Electronic Journal of the Faculty of Civil Engineering Osijek-e-GFOS","volume":"5 1","pages":"12-18"},"PeriodicalIF":0.2,"publicationDate":"2014-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66265929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elevated nitrate concentrations in natural water sources are a worldwide concern due to the extensive levels of soil N-fertilization. This study investigates three commercially available polyethersulfone (PES) ultrafiltration (UF) membranes with different molecular weight cut-offs (5, 10, and 30 kDa), which we modified with a cationic surfactant, cetylpyridinium chloride to improve their nitrate removal. The nitrate removal efficiency of these membranes was examinated as functions of initial nitrate concentration, pH, and permeate flux. The best nitrate removal efficiency was obtained with a 5 kDa surface-modified UF membrane.
{"title":"NITRATE REMOVAL FROM WATER USING SURFACE-MODIFIED ULTRAFILTRATION MEMBRANES","authors":"M. Habuda-Stanić, M. Nujić, V. Santo","doi":"10.13167/2014.8.8","DOIUrl":"https://doi.org/10.13167/2014.8.8","url":null,"abstract":"Elevated nitrate concentrations in natural water sources are a worldwide concern due to the extensive levels of soil N-fertilization. This study investigates three commercially available polyethersulfone (PES) ultrafiltration (UF) membranes with different molecular weight cut-offs (5, 10, and 30 kDa), which we modified with a cationic surfactant, cetylpyridinium chloride to improve their nitrate removal. The nitrate removal efficiency of these membranes was examinated as functions of initial nitrate concentration, pH, and permeate flux. The best nitrate removal efficiency was obtained with a 5 kDa surface-modified UF membrane.","PeriodicalId":53887,"journal":{"name":"Electronic Journal of the Faculty of Civil Engineering Osijek-e-GFOS","volume":"5 1","pages":"67-72"},"PeriodicalIF":0.2,"publicationDate":"2014-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66266018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we compared the performance limits of building codes and assessed whether these limits could be applied to wide beams. We performed a parametric study, investigating the longitudinal reinforcement ratio, beam width, steel class, and type and spacing of the transverse reinforcement. We obtained the following results from these analyses: Increasing the longitudinal reinforcement ratio reduced the deformation limit corresponding to code-based performance limits. Changing the confinement properties significantly affected the TEC 2007 and ASCE/SEI 41 limits. The performance limits defined by EC8 and ASCE/SEI 41 had similar corresponding plastic deformations, lower than those corresponding to the TEC 2007 strain-based damage limits. The results show that assessing the performance of wide beams by using the performance limits from different codes could produce contradictory results.
{"title":"A PARAMETRIC STUDY OF CODE-BASED PERFORMANCE LIMITS FOR WIDE BEAMS","authors":"E. Tore, Talip Demiral","doi":"10.13167/2014.8.1","DOIUrl":"https://doi.org/10.13167/2014.8.1","url":null,"abstract":"In this study, we compared the performance limits of building codes and assessed whether these limits could be applied to wide beams. We performed a parametric study, investigating the longitudinal reinforcement ratio, beam width, steel class, and type and spacing of the transverse reinforcement. We obtained the following results from these analyses: Increasing the longitudinal reinforcement ratio reduced the deformation limit corresponding to code-based performance limits. Changing the confinement properties significantly affected the TEC 2007 and ASCE/SEI 41 limits. The performance limits defined by EC8 and ASCE/SEI 41 had similar corresponding plastic deformations, lower than those corresponding to the TEC 2007 strain-based damage limits. The results show that assessing the performance of wide beams by using the performance limits from different codes could produce contradictory results.","PeriodicalId":53887,"journal":{"name":"Electronic Journal of the Faculty of Civil Engineering Osijek-e-GFOS","volume":"5 1","pages":"1-11"},"PeriodicalIF":0.2,"publicationDate":"2014-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66265922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Public investment projects are projects in which the public interest is paramount. The public administration generates public projects, which can be grouped into portfolios. We often witness poor, disordered public investment and project selection. One reason is the lack of adequate, consistent methodology for evaluating and selecting projects. It can be difficult to choose from comparable projects within the portfolio, and the attitudes of the stakeholders can hinder decision-making, highlighting the need for multi- criteria analysis. To select the best project, we designed a model to evaluate and rank public administration projects. We presented a hierarchical structure of objectives and criteria for comparing projects. To select and compare projects according to these defined criteria and assigned weights, we used PROMETHEE II. We simulated and validated this model using the portfolio of the city of Kastav. This model contributes to higher quality and more consistent decision-making in selecting the best investment project from a public administration portfolio.
{"title":"Establishing a model to evaluate public administration projects","authors":"I. Marović, D. Car-Pušić, Zlatko Hrvatin","doi":"10.13167/2014.8.7","DOIUrl":"https://doi.org/10.13167/2014.8.7","url":null,"abstract":"Public investment projects are projects in which the public interest is paramount. The public administration generates public projects, which can be grouped into portfolios. We often witness poor, disordered public investment and project selection. One reason is the lack of adequate, consistent methodology for evaluating and selecting projects. It can be difficult to choose from comparable projects within the portfolio, and the attitudes of the stakeholders can hinder decision-making, highlighting the need for multi- criteria analysis. To select the best project, we designed a model to evaluate and rank public administration projects. We presented a hierarchical structure of objectives and criteria for comparing projects. To select and compare projects according to these defined criteria and assigned weights, we used PROMETHEE II. We simulated and validated this model using the portfolio of the city of Kastav. This model contributes to higher quality and more consistent decision-making in selecting the best investment project from a public administration portfolio.","PeriodicalId":53887,"journal":{"name":"Electronic Journal of the Faculty of Civil Engineering Osijek-e-GFOS","volume":"5 1","pages":"56-66"},"PeriodicalIF":0.2,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66266009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
U radu je dan pregled svojstava poroznog betona te prikazane prednosti njegove uporabe u kolnickim konstrukcijama. Pripremljene su dvije mjesavine
这一天的工作是检查多孔混凝土的性质及其在殖民地建筑中使用的优势。准备了两个空格。
{"title":"PRIMJENA POROZNOG BETONA U KOLNIČKIM KONSTRUKCIJAMA","authors":"Melani Felja, Krunoslav Ćosić, Ivanka Netinger","doi":"10.13167/2013.7.7","DOIUrl":"https://doi.org/10.13167/2013.7.7","url":null,"abstract":"U radu je dan pregled svojstava poroznog betona te prikazane prednosti njegove uporabe u kolnickim\u0000 konstrukcijama. Pripremljene su dvije mjesavine","PeriodicalId":53887,"journal":{"name":"Electronic Journal of the Faculty of Civil Engineering Osijek-e-GFOS","volume":"4 1","pages":"68-75"},"PeriodicalIF":0.2,"publicationDate":"2013-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66265870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Major part of energy in conventional dwelling structures is used for space heating. At older dwelling structures with no heating insulation at outer walls, as well as structures with inadequate construction and heating insulation, heat losses are evident and unavoidable. Infra red thermography proved as a very powerful, successful and simple method for detecting heat losses through construction elements. It is possible to detect structural and insulation failings based on results interpretations without destruction, and thus to increase energy efficiency of structures by removing the failings. The paper gives an overview of IC thermography potential for detecting heat losses and for assessing energy efficiency of dwelling structures proven on several cases using FLIR i7 IC camera.
{"title":"TERMOGRAFIJA I ENERGETSKA UČINKOVITOST STAMBENIH OBJEKATA","authors":"R. Šišić, Amela Hodžić, Adi Kevilj, O. Hrustić","doi":"10.13167/2013.7.3","DOIUrl":"https://doi.org/10.13167/2013.7.3","url":null,"abstract":"Major part of energy in conventional dwelling structures is used for space heating. At older dwelling structures with no heating insulation at outer walls, as well as structures with inadequate construction and heating insulation, heat losses are evident and unavoidable. Infra red thermography proved as a very powerful, successful and simple method for detecting heat losses through construction elements. It is possible to detect structural and insulation failings based on results interpretations without destruction, and thus to increase energy efficiency of structures by removing the failings. The paper gives an overview of IC thermography potential for detecting heat losses and for assessing energy efficiency of dwelling structures proven on several cases using FLIR i7 IC camera.","PeriodicalId":53887,"journal":{"name":"Electronic Journal of the Faculty of Civil Engineering Osijek-e-GFOS","volume":"24 1","pages":"24-31"},"PeriodicalIF":0.2,"publicationDate":"2013-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66265756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nakon katastrofalnih posljedica potresa na Aljasci i u Niigati 1964. godine, Seed i Idriss su razvili i objavili metodu za procjenu otpornosti tla na
1964年阿拉斯加和尼里格发生地震，造成灾难性后果。年，Seed和Idriss在
{"title":"UTJECAJ ODZIVA PLITKO TEMELJENE ARMIRANOBETONSKE OKVIRNE KONSTRUKCIJE NA LIKVEFAKCIJSKI POTENCIJAL TLA","authors":"Damir Džakić, Ivan Kraus, Mensur Mulabdić","doi":"10.13167/2013.7.6","DOIUrl":"https://doi.org/10.13167/2013.7.6","url":null,"abstract":"Nakon katastrofalnih posljedica potresa na Aljasci i u Niigati 1964. godine, Seed i Idriss su razvili i objavili metodu za procjenu otpornosti tla na","PeriodicalId":53887,"journal":{"name":"Electronic Journal of the Faculty of Civil Engineering Osijek-e-GFOS","volume":"4 1","pages":"56-67"},"PeriodicalIF":0.2,"publicationDate":"2013-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66265858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Otpadne vode se moraju procistiti prije ispustanja u recipijent. Jedan od nacina prociscavanja otpadnih voda je prociscavanje biljnim uređaj
废水必须在排入接收器之前进行清理。评估废水的一种方法是评估工厂设备
{"title":"BILJNI UREĐAJI ZA PROČIŠĆAVANJE OTPADNIH VODA","authors":"Marija Šperac, Jelena Kaluđer, Željko Šreng","doi":"10.13167/2013.7.8","DOIUrl":"https://doi.org/10.13167/2013.7.8","url":null,"abstract":"Otpadne vode se moraju procistiti prije ispustanja u recipijent. Jedan od nacina prociscavanja otpadnih voda je prociscavanje biljnim uređaj","PeriodicalId":53887,"journal":{"name":"Electronic Journal of the Faculty of Civil Engineering Osijek-e-GFOS","volume":"4 1","pages":"76-86"},"PeriodicalIF":0.2,"publicationDate":"2013-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66265879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article deals with the material flow problems of a cylindrical conical steel silos during discharge. Since the silos discharge process belongs to one of the most critical load cases, it is necessary to be accounted for during design. During the silos discharge the several modes of material flow can occur. Due to fact that each of the flow modes result in significantly different pressures on the silos walls, from the safety and economical aspect, it is required to have reliable assessment of the discharge process. Depending on the silos purpose and stored material properties it is necessary to design with aim to achieve the desired discharging mode. In conclusion, the present work, through the numerical analysis, gave insights into how the small variations in the silos structural geometry can cause different discharging modes.
{"title":"PROJEKTIRANJE SILOSA S ASPEKTA NAČINA PROTOKA MATERIJALA PRI PRAŽNJENJU","authors":"Davor Skejić, M. Bolanča","doi":"10.13167/2013.7.2","DOIUrl":"https://doi.org/10.13167/2013.7.2","url":null,"abstract":"This article deals with the material flow problems of a cylindrical conical steel silos during discharge. Since the silos discharge process belongs to one of the most critical load cases, it is necessary to be accounted for during design. During the silos discharge the several modes of material flow can occur. Due to fact that each of the flow modes result in significantly different pressures on the silos walls, from the safety and economical aspect, it is required to have reliable assessment of the discharge process. Depending on the silos purpose and stored material properties it is necessary to design with aim to achieve the desired discharging mode. In conclusion, the present work, through the numerical analysis, gave insights into how the small variations in the silos structural geometry can cause different discharging modes.","PeriodicalId":53887,"journal":{"name":"Electronic Journal of the Faculty of Civil Engineering Osijek-e-GFOS","volume":"4 1","pages":"12-23"},"PeriodicalIF":0.2,"publicationDate":"2013-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66265748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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