Pub Date : 2024-03-25DOI: 10.7250/bjrbe.2024-19.628
Csaba Tóth, L. Petho, S. Rosta
The research project highlights the significance of incorporating reclaimed asphalt (RA) into hot mix asphalt (HMA) production for sustainable road construction. Despite limited RA utilization in Hungary in the past decades, the project demonstrates the feasibility of manufacturing HMA with significant RA content using advanced technology. The establishment of a capable asphalt plant and the development of laboratory assessments and mix design methodologies laid a solid foundation for future high RA integration in Hungarian road projects. Large-scale production trials confirmed the practicality of integrating high RA content into heavy-duty asphalt mixes with various binder types, including normal bitumen (B), polymer modified binder (PmB), and rubber modified bitumen (GmB). The large-scale validation project described in this paper was based on crucial binder blend designs carried out prior to the trials. Production control and performance-based laboratory testing proved that asphalt mixes can be designed and manufactured with high RA content while maintaining performance standards. Balancing resistance to distress modes like rutting and low-temperature cracking through careful binder blend design and mix design is achievable, even with high RA proportions. Visual assessments and production control indicated the uniformity of high RA content asphalt mixes. The details provided in this paper emphasise the potential for economic and environmental benefits through increased RA utilization in Hungarian road construction.
该研究项目强调了将再生沥青（RA）纳入热拌沥青（HMA）生产以实现可持续道路建设的重要意义。尽管过去几十年匈牙利对再生沥青的利用有限，但该项目证明了利用先进技术生产大量再生沥青的 HMA 的可行性。能力沥青厂的建立以及实验室评估和混合设计方法的开发，为未来匈牙利道路项目中的高 RA 融合奠定了坚实的基础。大规模生产试验证实，在重载沥青混合料中加入高 RA 含量的各种粘结剂（包括普通沥青（B）、聚合物改性粘结剂（PmB）和橡胶改性沥青（GmB））是切实可行的。本文所述的大规模验证项目基于试验前进行的关键粘结剂混合设计。生产控制和以性能为基础的实验室测试证明，沥青混合料的设计和生产可以在保持性能标准的前提下采用高 RA 含量。通过精心的粘结剂混合设计和混合料设计，即使采用高 RA 比例，也能实现抗车辙和低温开裂等破坏模式的平衡。目测评估和生产控制表明了高 RA 含量沥青混合料的均匀性。本文提供的详细信息强调了在匈牙利道路建设中提高 RA 利用率所带来的经济和环境效益潜力。
{"title":"Performance Characterisation of High RA Asphalt Mixes – A Laboratory and Field Study","authors":"Csaba Tóth, L. Petho, S. Rosta","doi":"10.7250/bjrbe.2024-19.628","DOIUrl":"https://doi.org/10.7250/bjrbe.2024-19.628","url":null,"abstract":"The research project highlights the significance of incorporating reclaimed asphalt (RA) into hot mix asphalt (HMA) production for sustainable road construction. Despite limited RA utilization in Hungary in the past decades, the project demonstrates the feasibility of manufacturing HMA with significant RA content using advanced technology. The establishment of a capable asphalt plant and the development of laboratory assessments and mix design methodologies laid a solid foundation for future high RA integration in Hungarian road projects. Large-scale production trials confirmed the practicality of integrating high RA content into heavy-duty asphalt mixes with various binder types, including normal bitumen (B), polymer modified binder (PmB), and rubber modified bitumen (GmB). The large-scale validation project described in this paper was based on crucial binder blend designs carried out prior to the trials. Production control and performance-based laboratory testing proved that asphalt mixes can be designed and manufactured with high RA content while maintaining performance standards. Balancing resistance to distress modes like rutting and low-temperature cracking through careful binder blend design and mix design is achievable, even with high RA proportions. Visual assessments and production control indicated the uniformity of high RA content asphalt mixes. The details provided in this paper emphasise the potential for economic and environmental benefits through increased RA utilization in Hungarian road construction.","PeriodicalId":506825,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":" 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384068","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}
Pub Date : 2024-03-25DOI: 10.7250/bjrbe.2024-19.629
Shahin Shabani, Jalal Ayoubinejad, N. B. Rahmanian
The sliding window method is a road network screening approach commonly used for identifying black spots. Previous studies have indicated that the selection of window length significantly impacts the black spot identification process. This research proposes a new method that optimizes the sliding window framework by examining its characteristics. The optimization methodology employed in this study is as follows: Firstly, the road is segmented, and for each segment, different scenarios of window lengths are chosen using the Density-Based Spatial Clustering of Applications with Noise algorithm. Next, a Safety Performance Function is developed to calculate the predicted and expected number of crashes, as well as the Potential Safety Improvement, for each window movement across all selected scenarios within the segment. Subsequently, the average differences are calculated using the analysis of variance, and the window length with the lowest dispersion of difference values from the mean is identified as the optimal length for each segment. The case study yielded noteworthy results, indicating that the utilization of the sliding window with optimal lengths led to the identification of 122 high-risk black spot-candidates. These points exhibit a higher crash density, effective length, and greater value in quantitative evaluation tests compared to the results obtained using windows with common fixed lengths.
{"title":"Identification of Road Black Spots Based on the Sliding Window Optimization and Safety Performance Function Development","authors":"Shahin Shabani, Jalal Ayoubinejad, N. B. Rahmanian","doi":"10.7250/bjrbe.2024-19.629","DOIUrl":"https://doi.org/10.7250/bjrbe.2024-19.629","url":null,"abstract":"The sliding window method is a road network screening approach commonly used for identifying black spots. Previous studies have indicated that the selection of window length significantly impacts the black spot identification process. This research proposes a new method that optimizes the sliding window framework by examining its characteristics. The optimization methodology employed in this study is as follows: Firstly, the road is segmented, and for each segment, different scenarios of window lengths are chosen using the Density-Based Spatial Clustering of Applications with Noise algorithm. Next, a Safety Performance Function is developed to calculate the predicted and expected number of crashes, as well as the Potential Safety Improvement, for each window movement across all selected scenarios within the segment. Subsequently, the average differences are calculated using the analysis of variance, and the window length with the lowest dispersion of difference values from the mean is identified as the optimal length for each segment. The case study yielded noteworthy results, indicating that the utilization of the sliding window with optimal lengths led to the identification of 122 high-risk black spot-candidates. These points exhibit a higher crash density, effective length, and greater value in quantitative evaluation tests compared to the results obtained using windows with common fixed lengths.","PeriodicalId":506825,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":" 1177","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140382278","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}
Pub Date : 2024-03-25DOI: 10.7250/bjrbe.2024-19.632
Michał Wymysłowski
This article presents an analytical method which takes into account the beneficial effects of the sheet piling located around the foundation in the calculations of ULS and SLS of shallow foundations. The analytical method proposed by the author was described in detail on the example of a “theoretical bridge” with the assumed geometry and loads as well as with the assumed subsoil and water conditions under the bridge. The stresses in the subsoil under the foundation and the settlement were determined. The author’s method was also used to calculate the foundation settlement of an “existing bridge” located in Gdańsk (Poland). In both cases, the results were compared with the results obtained using PLAXIS 3D Advanced 2023.1 and additionally with geodetic measurements for “existing bridge”. The author’s proposal was based on the EN 1997-1: Eurocode 7 standard applicable in the European Union. It has original elements that are not included in the cited standard. The proposed method is not the only one that could be used to assess the limit states of shallow foundations with sheet piling cover. However, it is based on the applicable regulations, gives similar results to the results obtained with FEM and geodetic measurements.
本文介绍了一种分析方法，该方法在计算浅基础的超限荷载和限载荷时考虑了位于基础周围的钢板桩的有利影响。作者提出的分析方法以一座 "理论桥梁 "为例进行了详细描述，该桥梁具有假定的几何形状和荷载，以及假定的桥下基土和水条件。确定了地基下的基土应力和沉降。作者的方法还用于计算位于波兰格但斯克的一座 "现有桥梁 "的地基沉降。在这两种情况下，计算结果都与使用 PLAXIS 3D Advanced 2023.1 获得的结果进行了比较，此外还与 "现有桥梁 "的大地测量结果进行了比较。作者的建议是基于适用于欧盟的 EN 1997-1：Eurocode 7 标准。它具有引用标准中未包含的原创元素。所提议的方法并不是唯一可用于评估带有钢板桩覆盖层的浅基础极限状态的方法。不过，该方法以适用法规为基础，得出的结果与使用有限元法和大地测量法得出的结果相似。
{"title":"Limit States of Shallow Bridge Foundations With Sheet Piling Covers","authors":"Michał Wymysłowski","doi":"10.7250/bjrbe.2024-19.632","DOIUrl":"https://doi.org/10.7250/bjrbe.2024-19.632","url":null,"abstract":"This article presents an analytical method which takes into account the beneficial effects of the sheet piling located around the foundation in the calculations of ULS and SLS of shallow foundations. The analytical method proposed by the author was described in detail on the example of a “theoretical bridge” with the assumed geometry and loads as well as with the assumed subsoil and water conditions under the bridge. The stresses in the subsoil under the foundation and the settlement were determined. The author’s method was also used to calculate the foundation settlement of an “existing bridge” located in Gdańsk (Poland). In both cases, the results were compared with the results obtained using PLAXIS 3D Advanced 2023.1 and additionally with geodetic measurements for “existing bridge”. The author’s proposal was based on the EN 1997-1: Eurocode 7 standard applicable in the European Union. It has original elements that are not included in the cited standard. The proposed method is not the only one that could be used to assess the limit states of shallow foundations with sheet piling cover. However, it is based on the applicable regulations, gives similar results to the results obtained with FEM and geodetic measurements.","PeriodicalId":506825,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":" 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140383912","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}
Pub Date : 2024-03-25DOI: 10.7250/bjrbe.2024-19.625
C. Machelski, Maciej Hildebrand, Maksymilian Kliński
The measurement of bridge deflection induced by a motor vehicle is an effective way of verifying the weight of the vehicle, and even of determining the layout of its axles. If the vehicle’s weight and the impacts of its individual axles are known, deflection measurements can be used to verify the stiffness of the bridge structure and to evaluate the effectiveness of steel-concrete composite span integration. The bridge in this case study had been specially permanently adapted to carrying very heavy loads, generated by overweight transports reaching the total weight of a few to over 10 MN. The results of measurements of span deflections induced by a heavy vehicle and the way they were used to assess the weight of another overweight transport unit crossing the bridge are presented in the paper. The existing strengthening of the bridge has been found to be universal and effective for various overweight transports.
{"title":"Investigation of the Stiffness of a Specially Strengthened Bridge When Crossed by Very Heavy Vehicles – A Case Study","authors":"C. Machelski, Maciej Hildebrand, Maksymilian Kliński","doi":"10.7250/bjrbe.2024-19.625","DOIUrl":"https://doi.org/10.7250/bjrbe.2024-19.625","url":null,"abstract":"The measurement of bridge deflection induced by a motor vehicle is an effective way of verifying the weight of the vehicle, and even of determining the layout of its axles. If the vehicle’s weight and the impacts of its individual axles are known, deflection measurements can be used to verify the stiffness of the bridge structure and to evaluate the effectiveness of steel-concrete composite span integration. The bridge in this case study had been specially permanently adapted to carrying very heavy loads, generated by overweight transports reaching the total weight of a few to over 10 MN. The results of measurements of span deflections induced by a heavy vehicle and the way they were used to assess the weight of another overweight transport unit crossing the bridge are presented in the paper. The existing strengthening of the bridge has been found to be universal and effective for various overweight transports.","PeriodicalId":506825,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"114 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381476","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}
Pub Date : 2024-03-25DOI: 10.7250/bjrbe.2024-19.630
J. Kreicbergs, Katerina Folla, J. Smirnovs
The aim of this article is to perform a comprehensive analysis of the data obtained during flow speed measurements on Latvian national roads. An algorithm for data selection was developed and implemented allowing for an analysis of comparable and unbiased traffic flow measurement data. In the course of the work, more than 150 000 000 traffic flow data records were received from the State Limited Liability Company Latvian State Roads for the period from autumn 2011 to the end of 2022. Above 30 000 000 records from 15 road sites were selected and processed. The results obtained during the analysis were visualized by depicting flow characteristics – average daily traffic, car proportion in traffic flow, average speed, speed histograms, speed rates V25, V50, V75, V90, V95, V99 and proportions of vehicles driven below various speed levels and speeding data. The data characterising the situation on Latvian national roads are intended to be used in the future traffic safety research.
{"title":"Road Traffic Flow Speed on Rural Roads in Latvia","authors":"J. Kreicbergs, Katerina Folla, J. Smirnovs","doi":"10.7250/bjrbe.2024-19.630","DOIUrl":"https://doi.org/10.7250/bjrbe.2024-19.630","url":null,"abstract":"The aim of this article is to perform a comprehensive analysis of the data obtained during flow speed measurements on Latvian national roads. An algorithm for data selection was developed and implemented allowing for an analysis of comparable and unbiased traffic flow measurement data. In the course of the work, more than 150 000 000 traffic flow data records were received from the State Limited Liability Company Latvian State Roads for the period from autumn 2011 to the end of 2022. Above 30 000 000 records from 15 road sites were selected and processed. The results obtained during the analysis were visualized by depicting flow characteristics – average daily traffic, car proportion in traffic flow, average speed, speed histograms, speed rates V25, V50, V75, V90, V95, V99 and proportions of vehicles driven below various speed levels and speeding data. The data characterising the situation on Latvian national roads are intended to be used in the future traffic safety research.","PeriodicalId":506825,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":" 74","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384173","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}
Pub Date : 2024-03-25DOI: 10.7250/bjrbe.2024-19.631
Andrzej Ambroziak, Maciej Malinowski, Mirosław Wałęga
The structural analysis of a road foldable prefabricated steel Bailey- type bridge located over the Tuga River in Żelichowo, Poland is performed in this paper. Interesting and untypical bridge redevelopment performed made it possible to lift the middle foldable bridge span by approximately 4.0 m concerning the existing state. The paper begins with a survey of literature carried out on the investigations of foldable Bailey-type bridge subject matter. A description of the numerical modelling of foldable prefabricated bridges is performed. The comparison of the proof load test results with the FEM numerical model results has shown very good compatibility. This paper can provide scientists, engineers, and designers the basis for structural analysis in the field of foldable Bailey-type bridge constructions and numerical simulations.
{"title":"Rebuilding Bailey Bridge to Bridge With Bascule Span – A Case Study","authors":"Andrzej Ambroziak, Maciej Malinowski, Mirosław Wałęga","doi":"10.7250/bjrbe.2024-19.631","DOIUrl":"https://doi.org/10.7250/bjrbe.2024-19.631","url":null,"abstract":"The structural analysis of a road foldable prefabricated steel Bailey- type bridge located over the Tuga River in Żelichowo, Poland is performed in this paper. Interesting and untypical bridge redevelopment performed made it possible to lift the middle foldable bridge span by approximately 4.0 m concerning the existing state. The paper begins with a survey of literature carried out on the investigations of foldable Bailey-type bridge subject matter. A description of the numerical modelling of foldable prefabricated bridges is performed. The comparison of the proof load test results with the FEM numerical model results has shown very good compatibility. This paper can provide scientists, engineers, and designers the basis for structural analysis in the field of foldable Bailey-type bridge constructions and numerical simulations.","PeriodicalId":506825,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"116 45","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381692","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}
Pub Date : 2024-03-25DOI: 10.7250/bjrbe.2024-19.627
Junxian Chen, Yonggang Wang
Sharp curves are vulnerable sections for rollover accidents. This study was conducted to investigate the effects of transition curve and superelevation on the critical speed and critical braking distance of truck rollovers. Using different transition types (spiral, Bloss and Grabowski curve) and different superelevation values (6%, 120 m transition length and 8%, 160 m) as variables, experiments of constant speed driving and hard braking were simulated and conducted by Trucksim. Conclusions regarding the influence of these road design factors on the stability of vehicles were then proposed. Grabowski curve allowed for the maximum critical rollover speed. The difference in critical rollover speed between different transition types was only determined by the length of the transition section. Simply extending the length of the transition section increased the critical rollover speed of spiral curve, at the same time decreasing the critical speed of Bloss and Grabowski curve. Hard braking experiments showed completely different characteristics. As the initial speed increased, only spiral curve became safer. Increasing superelevation made the braking behaviour of the vehicle more dangerous and fraught with uncertainties due to different target speed, starting curvature and changing superelevation. Based on these findings, a number of useful recommendations for drivers and road designers were put forward.
{"title":"Effects of Transition Curves and Superelevation on the Critical States of Truck Rollovers on Sharp Curves","authors":"Junxian Chen, Yonggang Wang","doi":"10.7250/bjrbe.2024-19.627","DOIUrl":"https://doi.org/10.7250/bjrbe.2024-19.627","url":null,"abstract":"Sharp curves are vulnerable sections for rollover accidents. This study was conducted to investigate the effects of transition curve and superelevation on the critical speed and critical braking distance of truck rollovers. Using different transition types (spiral, Bloss and Grabowski curve) and different superelevation values (6%, 120 m transition length and 8%, 160 m) as variables, experiments of constant speed driving and hard braking were simulated and conducted by Trucksim. Conclusions regarding the influence of these road design factors on the stability of vehicles were then proposed. Grabowski curve allowed for the maximum critical rollover speed. The difference in critical rollover speed between different transition types was only determined by the length of the transition section. Simply extending the length of the transition section increased the critical rollover speed of spiral curve, at the same time decreasing the critical speed of Bloss and Grabowski curve. Hard braking experiments showed completely different characteristics. As the initial speed increased, only spiral curve became safer. Increasing superelevation made the braking behaviour of the vehicle more dangerous and fraught with uncertainties due to different target speed, starting curvature and changing superelevation. Based on these findings, a number of useful recommendations for drivers and road designers were put forward.","PeriodicalId":506825,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":" 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140383820","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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