Hasil untuk "Highway engineering. Roads and pavements"

Youssef Aouni, Souad El Moudni El Alami, Mohammed Berrahal et al.

Road and highway authorities rely on pavement management systems(PMS), in particular regular pavement condition inspections, to manage and preserve this infrastructural heritage. To this end, visual surveys are regularly conducted to detect and classify pavement damage, assess pavement condition, and derive performance indicators. However, manual pavement inspection can be a subjective and time-consuming process that requires a high level of skill from those responsible for inspection and monitoring. This study proposes a machine learning (ML) technique to automatically classifying digital images of national road surfaces captured by a camera mounted on a smart vehicle equipped with a multifunctional road inspection system (SMAC). The image dataset, captured on different roads in Morocco, includes five classes of pavement damage and one class of no damage. The experimental results indicate that the ResNet50 model achieves superior classification accuracy of approximately 94%. This research contributes to the automation of road monitoring processes and provides road managers with an effective tool for planning and executing maintenance operations with enhanced reliability and efficiency.

Jan Dziuban

Abstract: The review of space applications of MEMS sensors as well as the fi rst presentation of plasma fluid optical gas microspectrometer and ion mass microspectrometer, developed in Poland for future Venusian, Martian and Lunar missions have been presented. Additionally, Polish subminiature biomedical lab-on-chip payload and its space tests at LOE has been showed. Finally CSAC atomic microclock and its applications has been discussed. Keywords: MEMS; Space; Miniaturization; Spectrometer; Lab-chip; CSAC

Wardana Galih Pamungkas, M. Latif, S. Sulistyowati

CBR (California Bearing Ratio) is a soil-bearing capacity test developed by the California State Highway Department. The principle of this test is penetration testing, which inserting an object into the sample. This way, the strength of the base soil or other materials used to make road pavements can be assessed. The main problem in this report is the lack of understanding and skills of civil engineering students in conducting CBR tests, and in assessing the bearing capacity of the base soil as a foundation layer of road pavements. Students are often constrained in understanding the basic principles of CBR tests, the use of laboratory equipment, and the interpretation of test results. This activity aims to improve student understanding through a combination of theoretical learning methods, discussions, and direct practice in the laboratory using standard procedures SNI 1738-2011 and SNI 1744-2012. The implementation of the test involves soil sample preparation, CBR test penetration testing, and analysis of results through a graph of the relationship between load and penetration depth. The results show that the increase in student understanding, as evidenced by the difference in pre-test and post-test scores indicated an increase in test implementation and analysis of the results. Students who initially did not understand the procedure and importance of CBR testing are now able to use it in the context of road pavement planning. In conclusion, this training has succeeded in improving students' competence in understanding and applying CBR testing, which will support them in civil engineering practices, especially in the design and analysis of road structure resistance based on soil-bearing capacity.

Xiwen Chang, Feng Wang, Rui Wu et al.

Recently, researchers in the road field are focusing on the development of green asphalt materials with lower emission of volatile organic compounds (VOCs). The characterization methodology of asphalt VOCs and the influencing factors on VOCs release have always been the basic issue of asphalt VOCs emission reduction research. Researchers have proposed a variety of asphalt VOCs characterization methodologies, which also have mutually irreplaceable characteristics. Asphalt VOCs volatilization is affected by many factors. In this study, asphalt VOCs characterization methodologies were summarized, including their advantages, disadvantages, characteristics and applicable requirements. Subsequently, the influencing factors of VOCs release, such as asphalt types and environment conditions, are summarized to provide theoretical support for the emission reduction research. The classification and mechanism of newly-development asphalt VOCs emission reduction materials are reviewed. The reduction efficiencies are also compared to select better materials and put forward the improvement objective of new materials and new processes. In addition, the prospects about development of VOCs release mechanism of asphalt materials during the full life cycle and feasibility research of high-efficiency composite emission reduction materials in the future were put forward.

Bohdan Zelenskyi

Introduction. This article explores the use of artificial intelligence (AI) to monitor the technical condition of bridges and predict the service life of structures. It outlines the relevance of this issue, analyzes recent research and publications, defines the purpose and objectives of the study, and describes the main material, results, conclusions, and prospects for further research. Problem Statement. Monitoring the technical condition of bridges and predicting their service life requires a lot of time to process the results of the survey and determine the actual technical condition of the bridge elements. Purpose. To analyze the possibility of using artificial intelligence to monitor the technical condition of bridges and predict their service life. To establish the reliability of the data obtained in comparison with traditional methods of assessing the technical condition. Materials and methods. To analyze the possibility of using artificial intelligence to monitor the technical condition of bridges, we use available resources and databases on the Internet. State standards and regulations in force in Ukraine are used as initial data for the assessment. Results. The analysis of foreign sources on the available software for the implementation of artificial intelligence in the system of monitoring the technical condition of structures was carried out. Conclusions. The introduction of artificial intelligence-based software for monitoring the technical condition of bridges will significantly improve and accelerate the process of analysis, evaluation, preparation of conclusions and recommendations for the further operation of transport facilities.

Mingjing Fang, Yiming Chen, Yungang Deng et al.

Traditional cement concrete has the disadvantages of low tensile strength, poor toughness, and rapid development of cracks while cracking, which causes a significantly negative influence on the safety and durability of concrete road pavement. This paper presents a state-of-the-art review of toughness improvement mechanisms and evaluation methods of cement concrete for road pavement. The review indicates that (i) The performance of concrete material depends on its material composition and internal structure. Aggregate size, cement properties and admixtures are the main factors of concrete toughness. (ii) The incorporation of rubber or fiber in pavement concrete improves the toughness of concrete materials. However, these additions must be maintained within a reasonable range. The amount of rubber and fiber are encouraged not more than 30% of the volume of fine aggregate and 2% of the volume of concrete, respectively. (iii) The toughness of pavement concrete material includes the toughness regarding bending, impact and fracture. The toughness of cement concrete for highway and municipal pavement is generally evaluated by bending and fracture toughness, while the toughness of airfield pavement concrete is more focused on impact toughness. (iv) The toughening measures of cement concrete for road pavement are mainly mixed with rubber or fiber, while these two materials have their defects, and the application of high-toughness cement concrete in the actual road still faces many challenges. For example, the synergistic effect of rubber and fiber, the development and application of new flexible admixtures, and the formulation of the toughness index of pavement cement concrete materials need further research.

Mariusz Wesołowski, Krzysztof Blacha, Adam Poświata

from the network of military and civil airports, are highway landing strips, which function, importance and usefulness have taken on a special dimension in the current geopolitical situation, especially during the ongoing armed conflict in Ukraine. Highway Landing Strips (Polish. DOL) are specially prepared sections of public roads adapted to perform air operations of take-off and landing of military aircraft (Polish. WSP) intended for operational tasks during crisis and war, as well as tasks resulting from the implementation of the flight training process. Detailed information on the requirements for DOL is presented in NO-17- A207:2022 Airfield pavements – Airfield road strips – Requirements and tests [1]. The above normative document outlines the minimum requirements for geometric dimensions, runway obstacle free zones and DOL surface construction systems. Requirements for the basic operating parameters of pavements on facilities used by road services have been presented. In addition, these requirements should be primarily used in designing and constructing DOL, modernizing and reconstructing the existing road sections of airfields, accepting the performed works, and technical and operational assessment. The normative provisions are appropriate for assessing the technical condition of DOLs throughout their entire technical lifetime, especially during their use by military aircraft. The technical and operational condition of the DOL surface has a direct impact on the safety of air operations. This enforces the need for up-to-date, full knowledge about their technical condition, which will help make the appropriate decisions to ensure their safe operation. The article presents the results of testing the operational parameters of the newly built structures of the surface of the Highway Landing Strip of Wielbark airport along provincial road No. 604 and the requirements of the applicable defence standard NO-17-A207:2022. The possible operational hazards for performing air operations by military aircraft and the ongoing works aimed at improving the security of the DOL, which are part of the critical and defence infrastructure of the country, are also discussed. Keywords: Road section of the airport; Critical infrastructure; Defence; Security; Airport pavement

Babak Karimi

Freeze-thaw cycles have a significant negative effect on the engineering behaviour of soil in cold regions. In this study, the compressive strength of stabilized, poorly graded sandy soil used in road pavement that was subjected to different freeze-thaw cycles was studied. Samples with three different particle shapes were stabilized with a binder developed by mixing polyvinyl acetate (PVAc) and ethylene glycol monobutyl ether (EGBE). The PVAc/EGBE weight ratio was 2:1, and PVAc was added at 1%, 2%, and 3% of the dry weight of the soil, with the effect of up to ten freeze-thaw cycles evaluated. Results showed that the addition of binder decreased optimum moisture content and increased compressive strength. An increase in particle roundness results in a decrease in the magnitude of compressive strength but increases the soil composite ductility. Changing particle shape from angular to rounded resulted in a more significant decrease in compressive strength than changing from rounded to well-rounded. The decrease in compressive strength is most significant between the first and fourth freezing-thawing cycles and marginal between the fourth and tenth. The negative effect of increasing the roundness of particles is compensated by increasing binder percentages.

Emad Maleki Tabrizi, Hamid Reza Tohidvand, Masoud Hajialilue-Bonab et al.

Industrial production of chemical cement leads to extreme emissions of greenhouse gases. Biological or bio-inspired sustainable materials for soil treatment projects can be employed instead of chemical cement to heal the carbon cycle in the ecosystem. The enzyme-induced calcite precipitation (EICP) method is one of the novel bio-inspired technologies that can be employed in soil treatment projects to increase desired properties of soils. While the monotonic and cyclic behavior of the enzymatically treated sands has been investigated comprehensively, the strain accumulation pattern in these improved soils under cyclic traffic loads has not been evaluated yet. In this paper, confined and unconfined cyclic compression tests are applied to the enzymatically lightly cemented sands, and the effects of the different parameters on their strain accumulation pattern are investigated for the first time in the literature. This study uses two types of specimens with unconfined compression strengths (UCS) equal to 42 ​kPa and 266 ​kPa. It is shown that the treated specimens have a rate-dependent behavior where cyclic loads with low frequencies lead to more resilient and plastic strains in the specimens. The results show that by approaching the maximum applied stresses to the UCS of the specimens (by breaking more calcite bonds between sand particles), the rate dependency behavior of specimens will reduce. Investigation of the effects of the cementation level demonstrated that by increasing the amount of the precipitated calcite from 0.38% to 0.83%, accumulated plastic strains are reduced almost 95% under the same loading condition. Effects of the initial static loads, confining pressures, the number of cycles, and amplitudes of the cyclic loads are also evaluated.

Artem Bezuglyi, Yuliya Bibyk, Ihor Hresko et al.

Introduction. The study of changes in prices for road construction materials facilitates the adoption of the right management decisions in the future and is a necessary prerequisite for the pricing process in the road industry. The dynamics of prices for the road construction materials is constantly changing and depends on the ratio of supply and demands of the domestic market. This is an important indicator, as it allows analyzing the price level for a certain period of time, make conclusions and predict future price levels and trends in the road construction materials market, get the needed information about the competitive environment. Today, assessing changes in the price for road construction materials is of practical importance for both customers and contractors who carry out works on road facilities, because it allows them to choose the suppliers with the most optimal price offer for their region. Problem statement. Under the market economic system, which is inherent in most modern countries and the world economy, price has a major impact on the national and world economy and is a complex economic category that is of great importance to all participants in the investment process. This article examines the dynamics of changes in prices for road construction materials and products used at road facilities. Prices for these material resources are constantly changing under the influence of various economic factors and other external and internal factors, so the dynamics of changes in prices for road construction materials and products in a market economy requires the deep study and understanding of their economic essence as well as determination of their impact on the total cost of road facilities. Purpose. The purpose of the article is to consider the dynamics of changes in prices for road construction materials in modern market relations. In order to comply with the principles of procurement established by Article 5 [1], in particular maximum economy and efficiency, researches are conducted for studying the situation on the market of road construction materials, analysis of commercial offers of suppliers and other sources of information, and the dynamics of their changes for the certain period of time. Materials and methods. Monitoring the dynamics of prices for road construction materials and products has to be performed during the entire investment process, for all types of road works financed at state expenses. Performing the systematic comparison of prices for road construction materials and products for a certain period of time allows to form a price base, the use of which then allows the selection of the material price from the supplier that, all things being equal (technical characteristics, delivery times, volumes etc.) is the lowest. The priority of this process is to ensure the appropriate level of objectivity of data, timeliness and relevance of processed information. Results. The study reveals the concept of dynamics of prices, determines its practical significance and analyzes the change in prices for road construction materials and products used in road works; the reasons that influenced the change in prices were identified, conclusions were made and proposals were presented to improve the situation on the market of road construction materials. Conclusions. With the help of the dynamics of price changes studies, price changes of producers and suppliers of road construction materials and products can be investigated to be taken into account in the preparation of the investment estimates, the bid price of the participant in the procurement procedure (contract price), as well as for their clarification when settling mutual payments for the work performed.

M. Montoya

Mery Silviana, Bunyamin, Lindawati

Penelitian ini dilakukan untuk menganalisis perbandingan tahanan nominal baut pada sambungan pelat baja secara eksperimen dan analitis dengan metode LRFD. Objek yang ditinjau yaitu sambungan pelat baja bertampang dua yang terdiri dari pelat penyambung dan pelat yang disambung dengan ketebalan yang sama. Pelat baja yang digunakan adalah pelat dengan ketebalan 8 mm dan 10 mm, baut yang dipakai pada penelitian, berdiameter 3/8 dan ½ inch. Perbandingan jumlah alat sambung yang ditinjau yaitu satu, dua, tiga dan empat baut. Jumlah total benda uji penelitian yang dibuat sebanyak 16 benda uji. Metode penelitian dilaksanakan dengan pengujian tarik  menggunakan Universal Testing Machine. Pengujian tarik sambungan batang tarik pelat baja dilakukan dengan memberikan beban tarik secara perlahan-lahan pada sambungan hingga sambungan runtuh. Tahanan nominal baut batang tarik yang didapatkan dari hasil pengujian akan dibandingkan dengan hasil analitis menggunakan Metode LRFD (Load Resistance and Factor Design). Dari hasil penelitian didapatkan selisih antara tahanan nominal baut dari hasil pengujian dan perhitungan teoritis adalah 3,37%. Hasil selisih persentase ini didapat dengan membandingkan nilai beban ultimit hasil eksperimen dengan perhitungan analitis tahanan nominal baut ultimit (tanpa faktor reduksi kekuatan ( ). Dari hasil perbandingan dapat disimpulkan bahwa dalam merencanakan kekuatan batang tarik baja, perhitungan kapasitas harus memasukkan faktor reduksi kekuatan agar batang tarik pelat baja dalam kondisi aman. Hal ini dikarenakan selisih persentase kekuatan yang sangat kecil antara ekseprimen dan analitis

Jose Manuel Sanz Garcia, Manuel Romana Garcia, Jose Antonio Ramos Garcia

Although the splash and spray phenomenon produced by heavy trucks on road pavements is not a significant issue in relation to traffic safety, it may cause considerable inconveniences for those driving cars or motorbikes. This paper addresses the issue of pavement engineering with regard to surface characteristics; particularly pavement texture and its influence on water mobilization and projection in conditions of wet weather and heavy traffic. Considering the theoretical concept of pavement macrotexture, the analysis starts with the hypothesis concerning a relationship between Mean Profile Depth (MPD) and water splashed during rain. In order to focus on the impact of texture on splash and spray, a field experiment was carried out to test the hypothesis using 5 test tracks on a range of different pavement textures. The experiment was performed using a Traffic Speed Drain Meter (TSDM), which is a new drainability survey device presented to PIARC for approval. This equipment employs the laser and image technology and allows one to simultaneously obtain MPD and water splash data. The results of drainability and MPD were compared for each test track. Having analysed the pavements with different MPD ranges in the experiment, it has been concluded that MPD and water splashed apparently have an inversely proportional relationship. In addition, the TSDM proved to be a suitable equipment (repeatability) at an affordable cost (high performance of data collection). Finally, it has been concluded that there is a way to reduce splash and spray adjusting the infrastructure rather trying to solve the issue modifying vehicle moving modes. Therefore, if the issue is properly addressed by civil engineers and road managers, road safety in the areas of heavy rain may be improved at an affordable cost. The experiment presented here is considered a starting point opening the path for further research.

Justyna Bójko, Marlena Wach

Terms related to the implementation of the Directive on the protection of the rights of whistleblowers By December 16, 2021, Directive (EU) 2019/1937 of the European Parliament and of the Council of October 23, 2019, on the protection of persons reporting breaches of EU law, the so-called Whistleblower Protection Directive (Directive). This directive will enter into force on 17 December 2021. This means that, at least for employers with 250 or more employees, the effective date of the provisions will be December 17, 2021. The directive provides for the possibility of postponing the implementation of obligations for entities employing 50 to 249 until December 17, 2023. employees. The obligation to protect whistleblowers will apply to all entrepreneurs employing more than 50 employees, but this criterion does not apply if the entrepreneur is covered by one of the EU acts listed in Annex I to the directive. This applies, inter alia, to regulations concerning financial aspects or AML (counteracting money laundering and terrorism), entities that participate in public procurement tenders or use EU funds as part of their activities. Then the entrepreneur is to be subject to the obligations to implement the whistleblower protection requirements, regardless of the number of employees. Additionally, the directive explicitly encourages the national legislator to extend the obligations also to other areas of law and a broader scope of entrepreneurs. Therefore, it will be specified in the Polish act implementing the Directive.

Piotr Świątecki

Abstract: A significant change was introduced to the legislation regulating the state-owned enterprises in the last decade of the 20th century. The change made it possible to transfer companies under control of different managerial entities on the basis of the so-called management contracts. In the following paper the author will give an account of the practices related to management contracts as concluded by the Ministry of Transport during the relevant period. Keywords: State-owned enterprise; Management contract; Transport

Pratiksha Patil, D. S. Patil

A well-developed transportation system plays vital role in economic development of the country. The huge increase in vehicular population creates traffic congestions on city roads. Thus, to reduce traffic bottleneck, creation of new road infrastructure as well as improvement of existing one has long term economic and social benefits. The economic benefits are calibrated on the basis of Economic Internal Rate of Returns (EIRR). The Mumbai and Pune are the major cities of Maharashtra state, due to economic and industrial development in those cities faces frequent and heavy traffic jam on highway connecting to both cities. The scope of present study consists of evaluating the impact on traffic and checking economic viability of the project. Strengthening and widening for six lanes flexible pavement which named as, Mumbai Pune section of NH-4. The HDM-4 is software used for checking the engineering and economic viability of the investment in this road project. It was observed that results obtained with improvement alternatives are economic viable. Keywords— Traffic congestions; Economic Internal Rate of Returns (EIRR); HDM-4 software; Economic viability; Social benefits.

A. M. Khalid

Pavement condition index is an important indication for road performance and safety driving. Abuse of highway roads always resulted in may difficulties like improper driving, long time of trips, travelers discomfort and many other problems. Uncontrolled traffic of heavy loaded trucks together with high temperatures and absence of road maintenance will certainly cause huge damages to asphalt pavement and as a result reduced road lifetime. In this paper an attempt was made to assess the necessary parameters that used to model pavement condition index by the use of bootstrapping via the SPSS ver. 23. The estimated parameters showed a reasonably reliable predictions when compared to actual data.

M. Alawi

this research emphasis on using laser scan technology with high positional accuracy and high density automation for modeling the road surface. Surface modeling is essential for all road maintenance applications. Road flexible pavement distresses will be classified and summarized. Five major categories of flexible pavement road distresses will be considered in this study. The study deals with issues of road surveying, the safety of surveyors, data acquisition methodology, data processing, assessment, analysis and achieved accuracy. The used methodology in this paper allows accurate determination of paving material volumes that should be milled off the upper layer of the road surface and the volume of the filling material required to achieve a smooth road surface. However, the present work shows that using terrestrial laser scanning technologies for modeling the road surface has advantages such as surveying speed, big roads, highways and tunnels. Also it provides the safety for surveyors and the absence of a disruption to traffic. 1INTRODUCTION ne of the main transportation systems in Saudi Arabia is the road system, which is developed in rapid manner. The main function of these roads is to connect the cities, towns and villages throughout the kingdom. Therefore, it is required to have roads with excellent pavements from structural and functional point of views. In the last five plans of Saudi Arabia, the Ministry of Transportation (MOT) did perform many projects to establish solid and strong infrastructure of ways with cost in billions of riyals, and now it is considered as long term national investment. The ministry of planning statistics in Saudi Arabia stated that the kingdom paid more than 4000 billion riyals through 27 years. From this it can be noticed how huge the investment in the roads network is. The kingdom established giant roads networks. In the year 1372H O MOHAMMAD H. ALAWI C: 27 the network roads increased from 240 km to more than 187000 km in the year 1418H. [3]. Due to the increase of population, technology, travelling, education etc., the demand of transportation people and goods will increase. To keep these roads safe and durable, maintenance should be taken in consideration. Pavement distress such as rutting, cracking, aging, stripping, raveling etc. cause a lot of problems and lack of comfort for vehicles and passengers. Also it may cause accidents due to unexpected stopping of cars. Moreover, failed pavements require costly maintenance and repairs which in turn cause restrictions to traffic flow, thus causing undesirable traffic congestion. Some of the solutions of these distresses are a complete removal or partial removal of the bituminous layer. In this study terrestrial 3D laser scanners are used. It is popular and is increasingly used in providing as-built and modeling data in transportation applications, including land surveying, archaeological studies, architecture, bridge structures, and highway surveys. Unlike the traditional total station of only making a few measurements in a minute, the terrestrial laser scanner captures thousands of surface points (i.e. point cloud) instead. After making a series of distance measurement in uniform angular increments in both horizontal and vertical planes, the terrestrial laser scanner can provide a detailed portrait of the surface of the object. Laser scanners can reduce lane closures, decrease risk of injuries, and increase productivity. The resulting point cloud and detailed 3D model allows engineers to extract all the required data in the office, decreasing or eliminating the need for surveyors to return to the site for additional measurements. Laser scanning technology is very economical with faster information processing speed and automation procedures as well as the aspect of information precision compared to other technologies with the same purposes. Compared to existing techniques systems from the high rate-of-capture and density of three dimensional data, laser scanning technology is much better. The greatest difference between Laser scanning technology and photogrammetry is each technology adopts active sensor and passive sensor. Different sensors support different way of getting and processing information as well as the form of information. Laser scanning technology allows a large amount of three-dimensional data including colours and intensity information and their rapid process. Furthermore, the survey of existing ground profiles is of particular importance for the design, construction and on-going maintenance of the road network. Road closure for surveying ground profiles, in particular for the high speed roads, is costly, easy to attract public discontent and not easy to be approved by the Police and Transport Department. To overcome the difficulties and for safety sake, the terrestrial laser scanner that employing the “contact-free” laser scanning technology is considered as a useful supplementary surveying tool for getting the road profiles without the need of road closure. The purpose of this study is to make full use of laser scanning technology for road surface surveying and for more accurate geometric information extraction for the roads. Furthermore, the suitable solutions for road surface maintenance will be suggested and detailed. 2CLASSIFICATION OF ROAD DISTRESSES In this paper road flexible pavement distresses are classified using survey instruments, information about these distresses will be summarized. Five major categories of flexible pavement road distresses are considered in this research [1, 2, 9], as shown in Fig.1. Figure 1 S.H.R.P Asphalt concrete surfaced pavement distress types C: 28 MANSOURA ENGINEERING JOURNAL, (MEJ), VOL. 41, ISSUE 1, MARCH 2016 Distresses occur in flexible pavements, causes, method of repairing, level of the distresses are summarized as following: a) Cracking 1Alligator (fatigue) cracking: Is a series of interconnected cracks that have many sided sharp angled pieces. Usually less than one foot on longest side. Chicken wire/alligator pattern. Occurs only in areas subjected to repeated loading (usually in wheel paths). Initially appears as longitudinal cracks:  Causes: fatigue failure under repeated traffic, weak or thin surface  Repair/maintenance techniques: surface seal, overlay or reconstruction  Low: if little cracks found parallel and not connected to each other  Moderate: if the cracks connected to each other but not deep (still at the surface)  High: if the cracks are connected to each other, separated and deep 2Block cracking: Is a rectangular piece of asphalt surface ranging in size from approximately one square feet to 100 square feet:  Causes: daily air temperature cycle, shrinkage of asphalt pavement surface,  Repair/maintenance techniques: surface seal, recycle or overlay,  Low: un spalled cracks with a mean width less than 6 mm, cracks with sealant in a good condition  Moderate: cracks that are moderately spalled, cracks with a mean width varies from 6 t0 19 mm.  High: cracks that are severely spalled with a mean width greater than 19 mm. 3Edge cracking: Is a crescent shaped cracks or fairly continuous cracks parallel to, and usually within one to two feet of, the outer edge of pavement.  Causes: when paved shoulders do not exist.  Repair/maintenance techniques: seal crack, partial or full depth patch  Low: if the cracks have a mean width less than 6 mm,  Moderate: if the cracks have a mean width varies from 6 mm to 19mm,  High: if the cracks have a mean width greater than 19mm. 4Longitudinal cracking: Cracks are relatively parallel to pavement centreline:  Causes: daily air temperature cycle, hardening of asphalt, poor paving lane joint,  Repair/maintenance techniques: seal crack, partial or full depth patch,  Light: if the cracks have a width less than 6 mm,  Medium: if the cracks have a thickness widths varies from 6 t0 19 mm,  Heavy: if the cracks have thickness widths greater than 19mm. 5Reflection cracking at joints: Is a crack in asphalt concrete overlay surfaces over jointed concrete pavements at original joints. Knowing slab dimensions beneath surface helps identify these cracks.  Light: if the cracks have a width less than 6 mm,  Medium: if the cracks have a thickness widths varies from 6 t0 19 mm,  Heavy: if the cracks have thickness widths greater than 19mm. 6Transverse cracking: Is a crack relatively perpendicular to pavement centreline (not load associated).  Causes: daily air temperature cycle, hardening of asphalt, poor paving lane joint,  Repair/maintenance techniques: seal cracks, partial or full depth batch,  Low: if the cracks have a width less than 6 mm,  Moderate: if the cracks have a thickness widths varies from 6 t0 19 mm,  High: if the cracks have thickness widths greater than 19mm. b) Patching and potholes 1Patch/patch deterioration: is apportion of pavement surface that has been removed and replaced  Causes: utility cut.  Repair/maintenance techniques: replace patch area.  Low: patch is in very good condition or has low severity distress of any type.  Moderate: patch has moderate severity distress of any type.  High: patch has high severity distress of any type. 2Potholes: is bowlshaped holes of various sizes in the pavement surface.  Causes: poor drainage, weakness of pavement surface, sub base or sub grade, thin surface.  Repair/maintenance techniques: partial or full depth patch.  Low: if the hole has a depth less than 25 mm, and area varies from 0.304 square meter to 0.912 square meter  Moderate: if the hole has a depth varies from 25 to 50 mm and area varies from 0.304 square meter to 0.912 square meter MOHAMMAD H. ALAWI C: 29  High: if the hole has a depth greater than 50 mm, and area greater than 0.912 square meter c) Surface deformation 1Rutting: is a longitudinal surface depression in the wheel path.  Causes: inadequate compaction, improper design, consolidation or lateral movement under traffic, lo

Bohián Pérez Stéfanov

Los siniestros viales en Costa Rica han cobrado la vida de más 1897 personas entre el 2012 y el 2016, de quienes el 86% fueron hombres, la gran mayoría conductores de carro o motocicleta. Del restante 14% de mujeres que fallecieron, más del 75% fueron pasajeras de algún vehículo, peatonas o ciclistas. Estos datos plantean una hipótesis: el sistema vial y la movilidad en Costa Rica, responden a una serie de condicionantes sociales, culturales e históricas, enmarcadas dentro de un esquema patriarcal en el cual predominan actitudes y roles de masculinidad y femineidad que propician una mayor exposición al riesgo de un siniestro vial y de sufrir lesiones mortales o graves entre los hombres que entre las mujeres, resultado de un sistema vial configurado desde el simbolismo impuesto por una mal entendida masculinidad. El artículo pretende ser un insumo inicial para generar una discusión mayor y más amplia sobre el impacto que tienen en la seguridad vial los roles sociales asociados con la condición de ser hombre o mujer.

Yongbao Wang, Renda Zhao, Yi Jia et al.

The reinforced concrete arch bridge with concrete-filled steel tubular stiffened skeleton is extensively used in the mountainous area of southwest China due to their long span and high stability. Beibanjiang Bridge located in Shanghai- Kunming high-speed railway, which had a record span of 445 m, has recently been completed in 2016. However, concrete creep and shrinkage have pronounced effects on the long-term deflection and stress redistribution of this bridge. Several concrete creep and shrinkage specimens in the natural environment were made to predict the long-term behaviour of this bridge accurately. They were used to measure the concrete creep and shrinkage of the core concrete and surrounding concrete used in the arch bridge. The test results were compared to ACI209 R-92 Prediction of Creep, Shrinkage and Temperature Effects in Concrete Structures model, 1990 CEB-FIP Model Code 1990: Design Code model, fib Model Code for Concrete Structures 2010 model and Creep and Shrinkage Prediction Model for Analysis and Design of Concrete Structures-Model B3. Based on the numerical fitting method, the fib Model Code for Concrete Structures 2010 model was modified to suit the concrete creep and shrinkage experimental results. Then, the modified fib Model Code for Concrete Structures 2010 model was used to predict the timedependent behaviour of a concrete arch bridge.