Tomasz E. Burghardt, A. Pashkevich, Kevin M. Wenzel
Road markings are a necessary safety feature on almost all roads. For appropriate performance they must be reflectorised with glass beads. To demonstrate the differences between traditional and modern thin-layer road marking solutions, four road marking systems were compared in the field. Based on measurements of retroreflectivity, influence of glass beads and paint on service life was estimated. The use of high-performance waterborne paint reflectorised with premium glass beads permitted for over sixfold extension of durability. Financial analysis demonstrated that the considerable additional expense associated with purchase of modern materials was fully offset through increased service life: even 65% savings could be realised in the long term. Subsequent analysis of the used glass beads under optical and scanning electron microscopes provided information about their surface; intact and damaged glass beads were observed. Surprisingly, damaged glass beads were found to have crater-like surface features instead of the expected scratches.
{"title":"A study of premium glass beads for road marking materials","authors":"Tomasz E. Burghardt, A. Pashkevich, Kevin M. Wenzel","doi":"10.7409/RABDIM.021.008","DOIUrl":"https://doi.org/10.7409/RABDIM.021.008","url":null,"abstract":"Road markings are a necessary safety feature on almost all roads. For appropriate performance they must be reflectorised with glass beads. To demonstrate the differences between traditional and modern thin-layer road marking solutions, four road marking systems were compared in the field. Based on measurements of retroreflectivity, influence of glass beads and paint on service life was estimated. The use of high-performance waterborne paint reflectorised with premium glass beads permitted for over sixfold extension of durability. Financial analysis demonstrated that the considerable additional expense associated with purchase of modern materials was fully offset through increased service life: even 65% savings could be realised in the long term. Subsequent analysis of the used glass beads under optical and scanning electron microscopes provided information about their surface; intact and damaged glass beads were observed. Surprisingly, damaged glass beads were found to have crater-like surface features instead of the expected scratches.","PeriodicalId":44000,"journal":{"name":"Roads and Bridges-Drogi i Mosty","volume":"41 1","pages":"125-138"},"PeriodicalIF":0.5,"publicationDate":"2021-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89093152","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}
R. Lusa, Paweł Skierczyński, Joanna Prasalska-Nikoniuk, J. Kraszewska
Under specific conditions water vapor condensates on traffic signs (dew), resulting in deterioration of retroreflective properties of the reflective film. The dew is visible in the form of black patches, which may render the sign illegible. The objective of the presented research was to limit dew formation through the use of materials with various thermal conductivity and determine the impact of material on intensity and speed of condensation. The tests were performed at a field test site, using traffic sign blanks made of various materials. Each sign was divided into 4 sections, using 2 types of retroreflective films (in 3 colors) with or without anti-dew film. The occurrence of dew was recorded by performing serial photographs of each sign. Luminance, coefficient of retroreflection and temperature distribution were measured and analyzed in terms of their changes in time. The results of the research confirmed that at the chosen field test site the impact of the materials on the intensity of dew formation was insubstantial.
{"title":"Evaluation of the impact of road sign material on the occurrence of dew","authors":"R. Lusa, Paweł Skierczyński, Joanna Prasalska-Nikoniuk, J. Kraszewska","doi":"10.7409/RABDIM.021.007","DOIUrl":"https://doi.org/10.7409/RABDIM.021.007","url":null,"abstract":"Under specific conditions water vapor condensates on traffic signs (dew), resulting in deterioration of retroreflective properties of the reflective film. The dew is visible in the form of black patches, which may render the sign illegible. The objective of the presented research was to limit dew formation through the use of materials with various thermal conductivity and determine the impact of material on intensity and speed of condensation. The tests were performed at a field test site, using traffic sign blanks made of various materials. Each sign was divided into 4 sections, using 2 types of retroreflective films (in 3 colors) with or without anti-dew film. The occurrence of dew was recorded by performing serial photographs of each sign. Luminance, coefficient of retroreflection and temperature distribution were measured and analyzed in terms of their changes in time. The results of the research confirmed that at the chosen field test site the impact of the materials on the intensity of dew formation was insubstantial.","PeriodicalId":44000,"journal":{"name":"Roads and Bridges-Drogi i Mosty","volume":"1 1","pages":"115-124"},"PeriodicalIF":0.5,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90964160","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}
W artykule przedstawiono autorską metode określenia przepustowości relacji podporządkowanych na skrzyzowaniu bez sygnalizacji,dolączających sie na jezdni glownej do kolejki pojazdow spowodowanej dzialaniem sygnalizacji świetlnej na kolejnym skrzyzowaniu. Zaproponowany sposob obliczenia przepustowości tych relacji sklada sie z czterech etapow. Na początku obliczono dlugośc pasa zwalnianą przez pojazdy opuszczające skrzyzowanie z sygnalizacją świetlną. W drugim etapie określono przepustowośc relacji prawoskretnej dolączającej sie do kolejki pojazdow. W kolejnym kroku obliczono przepustowośc relacji lewoskretnej dolączającej sie do kolejki pojazdow. Ostatni etap to obliczenie czasu blokowania skrzyzowania przez pojazdy poruszające sie w kolejce.
{"title":"An attempt to determine capacity of movements from minor entries in case of congestion on the major street","authors":"K. Gasz","doi":"10.7409/RABDIM.021.006","DOIUrl":"https://doi.org/10.7409/RABDIM.021.006","url":null,"abstract":"W artykule przedstawiono autorską metode określenia przepustowości relacji podporządkowanych na skrzyzowaniu bez sygnalizacji,dolączających sie na jezdni glownej do kolejki pojazdow spowodowanej dzialaniem sygnalizacji świetlnej na kolejnym skrzyzowaniu. Zaproponowany sposob obliczenia przepustowości tych relacji sklada sie z czterech etapow. Na początku obliczono dlugośc pasa zwalnianą przez pojazdy opuszczające skrzyzowanie z sygnalizacją świetlną. W drugim etapie określono przepustowośc relacji prawoskretnej dolączającej sie do kolejki pojazdow. W kolejnym kroku obliczono przepustowośc relacji lewoskretnej dolączającej sie do kolejki pojazdow. Ostatni etap to obliczenie czasu blokowania skrzyzowania przez pojazdy poruszające sie w kolejce.","PeriodicalId":44000,"journal":{"name":"Roads and Bridges-Drogi i Mosty","volume":"16 1","pages":"95-113"},"PeriodicalIF":0.5,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89429789","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}
Increasing mobility results in growing overcrowding of roads and streets. Attempts to improve travel conditions through an increase in road capacity usually only worsen the situation. The main purpose should be an increased share of public transport, including bicycle traffic, in the modal split. An increased share of bicycles in everyday traveling requires, however, a competitive advantage of that means of transport over other transport possibilities. It involves the need for adequate infrastructure which would provide bicycle users with the possibility to move efficiently, comfortably, and above all, safely. This paper describes the problems resulting from insufficient quality of the regulations on cycling infrastructure design and proposes directions of changes and complements that are vital for traffic safety. It applies mainly to design speed on bicycle routes, widening of bikeways on curves, bikeway clearances, and visibility on cycle crossings enabling uninterrupted cycling.
{"title":"Selected issues of designing cycling infrastructure in the aspect of road traffic safety","authors":"A. Brzeziński, K. Jesionkiewicz-Niedzińska","doi":"10.7409/RABDIM.021.005","DOIUrl":"https://doi.org/10.7409/RABDIM.021.005","url":null,"abstract":"Increasing mobility results in growing overcrowding of roads and streets. Attempts to improve travel conditions through an increase in road capacity usually only worsen the situation. The main purpose should be an increased share of public transport, including bicycle traffic, in the modal split. An increased share of bicycles in everyday traveling requires, however, a competitive advantage of that means of transport over other transport possibilities. It involves the need for adequate infrastructure which would provide bicycle users with the possibility to move efficiently, comfortably, and above all, safely. This paper describes the problems resulting from insufficient quality of the regulations on cycling infrastructure design and proposes directions of changes and complements that are vital for traffic safety. It applies mainly to design speed on bicycle routes, widening of bikeways on curves, bikeway clearances, and visibility on cycle crossings enabling uninterrupted cycling.","PeriodicalId":44000,"journal":{"name":"Roads and Bridges-Drogi i Mosty","volume":"60 1","pages":"75-89"},"PeriodicalIF":0.5,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85877489","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}
W pracy przedstawiono oryginalny model deformacji ściskanych pretow pryzmatycznych w zakresie dokrytycznym. Uwzgledniono trzy pojawiające sie sekwencyjnie etapy deformacji: skrocenie preta o osi prostoliniowej, etap przejściowy (rownoczesne odksztalcenie postaciowe i wyboczenie preta ściśliwego) oraz etap wyboczenia preta o osi nieściśliwej. Kolejne etapy deformacji wyodrebniono na podstawie analizy wynikow przeprowadzonego eksperymentu stateczności, w postaci wykresow zmian sily oraz skladowych przemieszczenia, naprezenia i odksztalcenia. Pojawienie sie przemieszczenia poprzecznego preta wyjaśniono jako skutek odksztalcenia powstalego po osiągnieciu maksymalnej wartości energii odksztalcenia postaciowego. Zweryfikowano kryterium utraty stateczności opisanej warunkiem maksymalnej energii odksztalcenia sprezystego. Omowiono przypadek utraty stateczności pretow smuklych, ktore przenoszą sile krytyczną, jak rowniez pretow średnich smuklości, dla ktorych stan graniczny jest określony warunkami przejścia do trzeciego etapu deformacji. W drugim z wymienionych przypadkow utraty stateczności wyodrebniono smuklości, przy ktorych wystepuje przeskok konfiguracji preta oraz smuklości, przy ktorych stan graniczny określony jest niestatecznością materialową.
{"title":"Subcritical deformation of the bridge structure compressed members","authors":"S. Imiełowski","doi":"10.7409/RABDIM.021.002","DOIUrl":"https://doi.org/10.7409/RABDIM.021.002","url":null,"abstract":"W pracy przedstawiono oryginalny model deformacji ściskanych pretow pryzmatycznych w zakresie dokrytycznym. Uwzgledniono trzy pojawiające sie sekwencyjnie etapy deformacji: skrocenie preta o osi prostoliniowej, etap przejściowy (rownoczesne odksztalcenie postaciowe i wyboczenie preta ściśliwego) oraz etap wyboczenia preta o osi nieściśliwej. Kolejne etapy deformacji wyodrebniono na podstawie analizy wynikow przeprowadzonego eksperymentu stateczności, w postaci wykresow zmian sily oraz skladowych przemieszczenia, naprezenia i odksztalcenia. Pojawienie sie przemieszczenia poprzecznego preta wyjaśniono jako skutek odksztalcenia powstalego po osiągnieciu maksymalnej wartości energii odksztalcenia postaciowego. Zweryfikowano kryterium utraty stateczności opisanej warunkiem maksymalnej energii odksztalcenia sprezystego. Omowiono przypadek utraty stateczności pretow smuklych, ktore przenoszą sile krytyczną, jak rowniez pretow średnich smuklości, dla ktorych stan graniczny jest określony warunkami przejścia do trzeciego etapu deformacji. W drugim z wymienionych przypadkow utraty stateczności wyodrebniono smuklości, przy ktorych wystepuje przeskok konfiguracji preta oraz smuklości, przy ktorych stan graniczny określony jest niestatecznością materialową.","PeriodicalId":44000,"journal":{"name":"Roads and Bridges-Drogi i Mosty","volume":"29 1","pages":"19-40"},"PeriodicalIF":0.5,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89933320","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}
Mastyks asfaltowy ma duzy wplyw na wlaściwości mieszanki mineralno-asfaltowej. O jego cechach decydują nie tylko wlaściwości poszczegolnych skladnikow, ale takze wzajemne proporcje miedzy nimi – glownie stosunek wypelniacz/lepiszcze. Do oceny mastyksu mozna stosowac te same metody badan, co do oceny asfaltow drogowych, traktując go jako lepiszcze o bardzo duzej lepkości. Wyniki badan mogą posluzyc do wstepnego projektowania skladu mieszanki asfaltu lanego, zwlaszcza w kontekście trwalości nawierzchni na obiektach mostowych, gdzie asfalt lany stanowi warstwe ochronną izolacji. W artykule przedstawiono wyniki badan ciągliwości mastyksu i odporności na deformacje trwale asfaltu lanego, zawierających asfalt drogowy 35/50 zmodyfikowany dodatkiem asfaltu naturalnego Trinidad Epure. Celem przeprowadzonych badan bylo ustalenie wplywu stosunku wypelniacz/lepiszcze oraz dodatku asfaltu naturalnego na umowną energie rozciągania w badaniu ciągliwości, a takze określenie korelacji pomiedzy wlaściwościami mastyksu zawierającego zmodyfikowane lepiszcze a cechami mieszanki asfaltu lanego.
{"title":"Influence of composition and properties of mastic with natural asphalt on mastic asphalt mixture resistance to permanent deformation","authors":"Krzysztof Kołodziej, Lesław Bichajło, T. Siwowski","doi":"10.7409/RABDIM.021.004","DOIUrl":"https://doi.org/10.7409/RABDIM.021.004","url":null,"abstract":"Mastyks asfaltowy ma duzy wplyw na wlaściwości mieszanki mineralno-asfaltowej. O jego cechach decydują nie tylko wlaściwości poszczegolnych skladnikow, ale takze wzajemne proporcje miedzy nimi – glownie stosunek wypelniacz/lepiszcze. Do oceny mastyksu mozna stosowac te same metody badan, co do oceny asfaltow drogowych, traktując go jako lepiszcze o bardzo duzej lepkości. Wyniki badan mogą posluzyc do wstepnego projektowania skladu mieszanki asfaltu lanego, zwlaszcza w kontekście trwalości nawierzchni na obiektach mostowych, gdzie asfalt lany stanowi warstwe ochronną izolacji. W artykule przedstawiono wyniki badan ciągliwości mastyksu i odporności na deformacje trwale asfaltu lanego, zawierających asfalt drogowy 35/50 zmodyfikowany dodatkiem asfaltu naturalnego Trinidad Epure. Celem przeprowadzonych badan bylo ustalenie wplywu stosunku wypelniacz/lepiszcze oraz dodatku asfaltu naturalnego na umowną energie rozciągania w badaniu ciągliwości, a takze określenie korelacji pomiedzy wlaściwościami mastyksu zawierającego zmodyfikowane lepiszcze a cechami mieszanki asfaltu lanego.","PeriodicalId":44000,"journal":{"name":"Roads and Bridges-Drogi i Mosty","volume":"17 1","pages":"57-73"},"PeriodicalIF":0.5,"publicationDate":"2021-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82576751","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}
Ensuring high standard of service of public transport is among the most important goals of sustainable mobility. One of the most promising subsystems of public transport in this respect is the tram transport. Trams are eco-friendly and able to transport large numbers of passengers. However, in order to shape an efficient tram system, it is important to minimize the possibility of occurrence of incidents involving trams and road vehicles at intersections of roadways and tram tracks. The paper presents a proposition of a method of analysis of incidents in such locations. For ensuring a comprehensive approach to safety problem, the analysis encompasses two aspects: temporal and spatial. The proposed method has been presented on the example of tram network of the Metropolis GZM (Metropolitan Association of Upper Silesia and Dąbrowa Basin) area. The analysis has enabled identification of causes of incidents for the two most hazardous intersections of roadways and tram tracks. For each of these locations, proposed solutions to improve the level of safety have been determined.
确保公共交通的高水准服务是可持续交通最重要的目标之一。在这方面，公共交通中最有前途的子系统之一是有轨电车。有轨电车是环保的，能够运送大量的乘客。然而，为了塑造一个高效的有轨电车系统，重要的是要尽量减少在道路和有轨电车轨道交叉路口发生有轨电车和道路车辆事故的可能性。本文提出了一种分析此类地点事件的方法。为了确保对安全问题的全面分析，分析包括两个方面:时间和空间。以上西里西亚和Dąbrowa盆地大都会协会(Metropolitan Association of Upper Silesia and Dąbrowa Basin)地区的有轨电车网络为例，介绍了该方法。该分析能够确定两个最危险的公路和电车轨道交叉路口的事故原因。对于这些地点，已经确定了提高安全水平的建议解决方案。
{"title":"The analysis of traffic safety on the intersections of roadways and tram tracks","authors":"R. Żochowska, M. Kłos, Piotr Soczówka","doi":"10.7409/RABDIM.021.003","DOIUrl":"https://doi.org/10.7409/RABDIM.021.003","url":null,"abstract":"Ensuring high standard of service of public transport is among the most important goals of sustainable mobility. One of the most promising subsystems of public transport in this respect is the tram transport. Trams are eco-friendly and able to transport large numbers of passengers. However, in order to shape an efficient tram system, it is important to minimize the possibility of occurrence of incidents involving trams and road vehicles at intersections of roadways and tram tracks. The paper presents a proposition of a method of analysis of incidents in such locations. For ensuring a comprehensive approach to safety problem, the analysis encompasses two aspects: temporal and spatial. The proposed method has been presented on the example of tram network of the Metropolis GZM (Metropolitan Association of Upper Silesia and Dąbrowa Basin) area. The analysis has enabled identification of causes of incidents for the two most hazardous intersections of roadways and tram tracks. For each of these locations, proposed solutions to improve the level of safety have been determined.","PeriodicalId":44000,"journal":{"name":"Roads and Bridges-Drogi i Mosty","volume":"3 1","pages":"41-56"},"PeriodicalIF":0.5,"publicationDate":"2021-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90647197","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}
Tomasz E. Burghardt, A. Pashkevich, Jacek Bartusiak
Road markings are a necessary safety feature that guides drivers. For visibility in darkness, when accident risk and severity are the highest, road markings must be reflectorised with glass beads to be visible when vehicle headlights shine on them. Renewal of thick-layer structured road markings that have lost retroreflectivity but have retained the structure mostly intact is performed through application of thin-layer paint coatings. Based on a field experiment, it was demonstrated that selection of premium glass beads profoundly extends the durability of the renewed markings, which could be further enhanced through the use of high-performance waterborne paint. Whereas the standard system based on solventborne paint and typically used glass beads failed after a single winter, the use of premium road marking system at least doubled the service life. The extended road marking service life translates to 50% savings in material consumption, 50-97% lower emissions of volatile organic compounds, and a decrease in long-term financial expense by 5-26%.
{"title":"Solution for a two-year renewal cycle of structured road markings","authors":"Tomasz E. Burghardt, A. Pashkevich, Jacek Bartusiak","doi":"10.7409/RABDIM.021.001","DOIUrl":"https://doi.org/10.7409/RABDIM.021.001","url":null,"abstract":"Road markings are a necessary safety feature that guides drivers. For visibility in darkness, when accident risk and severity are the highest, road markings must be reflectorised with glass beads to be visible when vehicle headlights shine on them. Renewal of thick-layer structured road markings that have lost retroreflectivity but have retained the structure mostly intact is performed through application of thin-layer paint coatings. Based on a field experiment, it was demonstrated that selection of premium glass beads profoundly extends the durability of the renewed markings, which could be further enhanced through the use of high-performance waterborne paint. Whereas the standard system based on solventborne paint and typically used glass beads failed after a single winter, the use of premium road marking system at least doubled the service life. The extended road marking service life translates to 50% savings in material consumption, 50-97% lower emissions of volatile organic compounds, and a decrease in long-term financial expense by 5-26%.","PeriodicalId":44000,"journal":{"name":"Roads and Bridges-Drogi i Mosty","volume":"22 1","pages":"5-18"},"PeriodicalIF":0.5,"publicationDate":"2021-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82861146","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}
The paper analyses the properties of Portland-composite cement CEM II/B-M (V-W) prepared by addition of mixture of siliceous and calcareous fly ashes – in percentage proportion of 20:0, 10:10, 20:10 or 15:15 – to Portland cement CEM I 42.5R. Blaine’s surface area of cements equalled 4000 ± 100 cm 2 /g. Hydration heat, standard consistency, initial setting time, soundness and compressive strength were analysed in the paper. Partial replacement of siliceous fly ash with calcareous fly ash in cement gives a Portland-composite cement CEM II/B-M (V-W) of strength class 52.5N or even 52.5R, if the percentage proportion of siliceous to calcareous fly ash is 20:10.
本文分析了在硅酸盐水泥CEM I 42.5R中分别以20:0、10:10、20:10、15:15的比例加入硅质和钙质粉煤灰混合料制备的硅酸盐复合水泥CEM II/B-M (V-W)的性能。Blaine水泥的表面积为4000±100 cm 2 /g。对水化热、标准稠度、初凝时间、稳固性和抗压强度进行了分析。当硅质粉煤灰与钙质粉煤灰的比例为20:10时，将水泥中的硅质粉煤灰部分替代得到强度等级为52.5N甚至52.5R的波特兰复合水泥CEM II/B-M (V-W)。
{"title":"The possibility of use of mixture of siliceous and calcareous fly ash for production of Portland-composite cement type CEM II/B-M (V-W) 52.5","authors":"E. Tkaczewska","doi":"10.7409/RABDIM.020.017","DOIUrl":"https://doi.org/10.7409/RABDIM.020.017","url":null,"abstract":"The paper analyses the properties of Portland-composite cement CEM II/B-M (V-W) prepared by addition of mixture of siliceous and calcareous fly ashes – in percentage proportion of 20:0, 10:10, 20:10 or 15:15 – to Portland cement CEM I 42.5R. Blaine’s surface area of cements equalled 4000 ± 100 cm 2 /g. Hydration heat, standard consistency, initial setting time, soundness and compressive strength were analysed in the paper. Partial replacement of siliceous fly ash with calcareous fly ash in cement gives a Portland-composite cement CEM II/B-M (V-W) of strength class 52.5N or even 52.5R, if the percentage proportion of siliceous to calcareous fly ash is 20:10.","PeriodicalId":44000,"journal":{"name":"Roads and Bridges-Drogi i Mosty","volume":"51 1","pages":"267-282"},"PeriodicalIF":0.5,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86189245","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}
The paper presents an example of analysis of concrete cracking during construction of a massive bridge element, together with a demonstration of the expert diagnostic work aimed at a comprehensive assessment of the causes of crack development. The finite elements method analysis software FE-tool ConTeSt Pro was used. In the presented case there were typical doubts as to the reason of concrete cracking, and the performed analysis enabled identification of thermal shock as the primary cause of the observed distress. Finite element numerical simulations were adopted in order to analyze the temperature impact on crack development in the bridge elements. The complex case study analysis presented in the article may be treated as guidance on the use of scientific analysis methods in practical reinforced concrete cracking diagnostics. As a result of the work, thermal shock was identified to be the main reason for the damage of the massive bridge elements.
{"title":"Thermal shock as a cause of cracking of concrete in massive bridge support elements - a case study","authors":"P. Woyciechowski, P. Łukowski, G. Adamczewski","doi":"10.7409/RABDIM.020.019","DOIUrl":"https://doi.org/10.7409/RABDIM.020.019","url":null,"abstract":"The paper presents an example of analysis of concrete cracking during construction of a massive bridge element, together with a demonstration of the expert diagnostic work aimed at a comprehensive assessment of the causes of crack development. The finite elements method analysis software FE-tool ConTeSt Pro was used. In the presented case there were typical doubts as to the reason of concrete cracking, and the performed analysis enabled identification of thermal shock as the primary cause of the observed distress. Finite element numerical simulations were adopted in order to analyze the temperature impact on crack development in the bridge elements. The complex case study analysis presented in the article may be treated as guidance on the use of scientific analysis methods in practical reinforced concrete cracking diagnostics. As a result of the work, thermal shock was identified to be the main reason for the damage of the massive bridge elements.","PeriodicalId":44000,"journal":{"name":"Roads and Bridges-Drogi i Mosty","volume":"14 1","pages":"297-313"},"PeriodicalIF":0.5,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90050509","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：