Road Barriers Research Articles

Enhancing Concrete Properties With Rubber Additives: Experimental Analysis And Performance Evaluation

This research investigates the effect of adding recycled rubber to concrete mixes as part of efforts to enhance environmental sustainability and improve the mechanical properties of concrete. The study focuses on evaluating the mechanical and physical performance of rubberized concrete by analyzing its properties such as compressive strength, tensile strength, and workability. Partial replacement of rubber by 0% to 15% of fine aggregate in concrete was studied, with standard tests conducted to determine the effect of rubber on overall performance. The importance of the research lies in providing a dual solution of reducing environmental waste from used tires, while improving some properties of concrete in non-structural applications. The results show that rubberized concrete achieves important advantages such as improved flexibility, abrasion resistance, and light weight, despite a slight decrease in compressive strength. The research also highlights the potential of using rubberized concrete in non-structural applications such as pavements, road barriers, and shock absorption systems. The research concludes by recommending further studies to improve the adhesion between rubber and concrete mix components, while exploring innovative applications to expand the use of rubberized concrete in sustainable construction projects.

Investigating Factor Associations in Barrier Crashes through Cluster Correspondence Analysis

Roadside and median barriers have proven effective in preventing crashes; however, a significant number of crashes still occur that involve road barriers across United States. This study focuses on analyzing the factors related to barrier crashes across Texas. The dataset includes 63,475 crashes involving road barriers and covering six years of crash data (2017–2022). Using cluster correspondence analysis (CCA) data mining approach, the study identifies six different clusters of crashes. Each cluster identifies factors contributing to barrier-related crashes. Before implying the CCA, variable importance analysis is also performed to identify the significance of the variables. The analysis highlighted that dry road surface conditions and clear weather are highly associated with high-speed crashes. Driver distraction and absence of traffic control devices can attribute to the crashes on roads with lower speed limits. Moreover, along with other factors, adverse weather conditions are also found to be a contributing factor that can influence the crash frequency and type of crashes. The analysis also implies that non-complex crash type related to a single vehicle are highly correlated with barrier crashes. The study concludes by making several policy-making implications to assist the transportation planners in reducing the frequency and severity of barrier-related crashes.

Evaluation of Road Safety Hazard Factors in Egypt Using Fuzzy Analytical Hierarchy Order of Preference by Similarity to Ideal Solution Process

To address road accident losses, there is a need to prioritize safety factors, especially in high-risk locations on the road network, toward assuring a sustainable transport system. This paper proposes an approach for quantitative risk assessments of safety factors in hazardous road locations and involves the integration of the Fuzzy logic model, the Analytic Hierarchy Process (FAHP) and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). This new innovative method offers a way to prioritize and select safety factors associated with hazardous locations using a hierarchical structure. To demonstrate the applicability of this method, a case study was conducted in Egypt. The assessment process involved active participation by professionals through multiple expert meetings. This collaborative approach ensures that the assessment incorporates valuable real-world knowledge and experiences. It analyzed road safety hazardous conditions across various sections, including intersections, non-intersection sections, narrow bridge sections, and curve sections. The application of FAHP-TOPSIS enables the determination of weights for safety factors within each section, facilitating the evaluation of safety indices between them and ranking the safety hazard sections. The achieved analysis revealed that the hazard safety factor index is comparatively higher in curved sections compared to other types of sections. Light utility poles and road barriers significantly affected the hazard index. By utilizing this approach, governments may make informed decisions regarding the allocation of resources and the implementation of safety measures at hazardous road locations.

Automobile response to road safety barriers upon collision

During a collision between an automobile and a road safety barrier, the vehicle will go through many behavior transition phases. This research will focus on determining the behavior of two car models including a sedan car and a pickup truck in collision with two safety road barriers using numerical simulation. This paper will also present images, total force graphs, and velocity graphs throughout the process to evaluate the vehicle's behavior at different impact speeds and angles. It is recognized that at similar impact speeds, collision angles, and barrier types, the pickup truck suffers more damage than the sedan. In addition, the pickup truck colliding with a concrete barrier exhibits the highest force, while the sedan colliding with a W-Beam barrier records the lowest force among the four collision types. Regarding the road safety barrier, the concrete barrier has a shorter force increase/decrease duration than the W-Beam barrier.

Discrete element method simulation of high-speed vehicle collisions with road barrier systems

AbstractThe behavior of road or perimeter protection barriers under vehicle impact are usually investigated based on crash tests and finite element (FE) numerical approaches, which are ether expensive or time-consuming. Several studies have proposed to reduce the computation time of the numerical analysis by substituting the complex FE models of vehicles using simplified mass–spring–damper system models. However, these models have drawbacks since consideration of different vehicle impact angles is difficult and they are unable to correctly simulate the risk of high-speed vehicle collision running over the barrier. In this paper, a new approach is proposed to simulate the collision of vehicles with barriers based on the discrete element method (DEM). Here, to save computation time only a handful of 3D non-spherical particles are used to represent the barrier and vehicle. These particles are generated based on the super-quadric function, which is capable of generating a variety of shapes needed for the model. The contact detection and evaluation are carried out based on discrete function representation of the particles with uniform sampling. The bond between two discrete elements is defined using a nonlinear cohesive beam model since the distance between the elements is relatively large. The simulation results obtained based on this approach are more accurate and complete than the simplified mass–spring models and computationally more efficient than the FE model.

Nonlinear dynamic finite element analysis of vehicle impacts into road restraint systems

Despite that the safety of cars is continuously increasing, improving the safety of road transportation remains a key issue of modern society. The design of suitable road restraint systems plays an important role. As the tests of barriers are technically demanding and expensive, and road traffic intensity is continuously growing, it is crucial to develop advanced models that would make it possible to explore various scenarios under which road vehicles may accidently impact into the road restraint barrier. The submitted study focuses on the use of nonlinear dynamic finite element analysis (NLDFEA) in the reliability assessment of road restraint systems, with a particular focus on steel barriers subjected to impacts by heavy vehicles. The outcomes of theoretical analyses are compared with the results in a compiled unique database of full-scale road barrier impact test results. It appears that a good match between crash test results and the validated NLDFEA model can be achieved, differences being mostly within a range of 10 %. When modelling the crashes of buses and HGVs, it is particularly important to model correctly shape and geometry of the front and impacting side of the vehicle, tyre sizes, wheelbase and overall truck dimensions, and position of the centre of gravity of the vehicle including trailer and cargo. Recommendations for subsequent research studies and for practical applications are finally provided.

Evaluation of the effect of road barriers on wildlife habitats

Despite limited research on the topic, understanding the barrier effect of roads on wildlife habitats in China is crucial for the placement of wildlife crossing structures. First, a habitat suitability evaluation model for goitered gazelle (Gazella subgutturosa) was established. Then, using the Linkage Mapper model, potential migration corridors were simulated along the expressway. The migration corridors were then overlaid with the crossing structures to evaluate the barrier effects of the expressway. A total of 12 barrier segments were identified by the results, eight of which were found to have crossing structures, and preliminary monitoring indicated that five of the bridges have been used by goitered gazelle (62.5%). Based on the results, recommendations for the mitigation of the barrier effect of expressways on goitered gazelle are provided.

Integrating visual factors in crash rate analysis at Intersections: An AutoML and SHAP approach towards cycling safety

Cycling crashes constitute a significant and rising share of traffic accidents. Consequently, exploring factors affecting cycling safety has become a priority for both governmental bodies and scholars. However, most existing studies have neglected the vision factors capable of quantitatively describing the city-level cycling environment. Moreover, they have relied on limited models that lack interpretability and fail to capture the spatial variations in the contribution of factors. To address these gaps, this research proposed a framework that used origin–destination-based cycling flow and vision factors generated from Google Street View images to identify the leading factors. It also employed the comparative Automatic Machine Learning and interpretable SHAP value-based geospatial analysis to explain each factor’s contribution to the cycling crash risk, with a particular focus on the spatial variations in the influence of vision factors. The effectiveness of this framework was validated by a case study in Manhattan, which examined the leading risk factors of cycling crash rates at intersections. The results showed that the LightGBM model, with selected subsets of factors, outperformed other models. Through SHAP explanations of global feature importance, the study identified the proportion of road barriers, the proportion of open sky, and the number of visible trucks as the leading visual risk factors. Additionally, using SHAP-based geospatial analysis, the study revealed the local variations in the effects of these three factors and identified eight areas with higher cycling crash rates. Based on these findings, the study provided practical measures for a safer cycling environment in Manhattan.

Changes in Physical Properties and Microstructure of Bamboo–Plastic Composites with Different Bamboo Powder/Polybutylene Succinate Ratios, Polypropylene, and Polyethylene

As the most promising biomass material, bamboo has been widely used, but at the same time, it is subject to many problems, such as processing residues and the failure of high-value utilization of residues. In this paper, bamboo powder and polybutylene succinate (PBS) were used as the main raw materials, and by changing the ratio of bamboo powder to PBS and adding polypropylene (PP) or polyethylene (PE) in combination with PBS, the effects of the ratio, as well as the effects of the use of PP and PE, on the physical–mechanical, thermal, and degradation properties of bamboo–plastic composites were investigated, and the microscopic changes of the materials were studied by chemical component analysis. The optimal formulation of bamboo powder/PBS composite material has been identified through experimentation, yielding a flexural strength of 24.87 MPa and a compressive strength of 29.74 MPa. This material can be used for outdoor furniture, wall panels, flooring, road barriers, and other applications, providing a new environmentally friendly approach to the consumption of residual bamboo materials.

Numerical Analysis of a Steel Hollow Beam Subjected to Axial Compression and Oblique Loadings

Over the past few decades there has been a growing interest in designing a structural component which is capable of absorbing a large amount of energy during impact. This so-called energy absorbers have found common usage in many applications such as in aircraft, automotive, and road barriers. This paper presents the crush analysis of a hollow square beam subjected to axial compression and oblique loadings. Quasi-static and dynamic numerical analyses using ANSYS finite element analysis commercial package were carried out on the beam subjected to various angles of oblique loadings applied at the edge of the beam to simulate one of the actual load cases which might occur in the event of impact. The isotropic strain hardening rule and the Johnson-Cook material models (for high strain rates) were utilized for the quasi-static and dynamic crush analyses respectively. Validation of the numerical analysis were carried out and the results were in good agreement with the published results which confirms the accuracy of the simulation scheme. Parametric study was performed for the steel hollow tube to investigate the effect of beam wall thickness, load obliquity, and the impact velocity onto the specific energy absorption (SEA) and the initial peak load. Based on the quasi-static analysis, it has been observed that the peak load and SEA increases with the beam wall thickness but linearly reduced when the oblique angles of the applied loadings are increased. On the other hand, increasing in the impact velocity has resulted in the increase in both the SEA and peak load.

Design of Automated Bascule Bridge and Collision Avoidance with Water Traffic

Abstract The development of movable bridges is a modern technological advancement that requires the integration of multi-disciplinary concepts such as control, automation, and design. In order to demonstrate how a collision avoidance system works, this research offers the design of an automated double-leaf bascule bridge with a pulley-rope moving mechanism and Pratt truss. The bridge is created where a settled railway or roadway intersection of a navigable stream cannot attain a steep profile. The design took into account the length, height, and width of the bridge as well as automatic ship identification and scaffold leaf movement activity for ship crossing. For the safe passage of cars on the bridge and for stopping vehicles during bridge movement, the system includes a collision avoidance control system and an automated road barrier system. After sensor adjustment, the model bridge’s performance under test produced results that were adequate, with a success rate of 100%.

A Smart Solution

Innovative moveable road barriers improve safety and mobility in tunnel work zones

Indexing the Maintenance Priority of Road Safety Barriers in Urban and Peri-Urban Contexts: Application of a Ranking Methodology in Bologna, Italy

The need for clear and updated information is pivotal when authorities plan and perform routinary, periodic and emergency maintenance of both road network and their roadside assets, e.g., curbs, signals, and barriers. With particular regard to road barriers, the development of remote sensing technologies, such as Laser Imaging Detection and Ranging (LiDAR), has played a disruptive role in acquiring information, so the surveys today are predominantly automatic, faster, and less biased than the traditional (i.e., visual and manual) inventorying methodologies. However, even though they are accurate, these emerging procedures usually focus only on the surveyed elements and do not provide any other information about the surrounding environment or about the qualitative degradation of the elements. The primary objective of this research effort was to present a ranking methodology for enhancing road safety in urban contexts. Due to an innovative synthetic index which takes into account both the deterioration and the location of the surveyed elements, maintenance priority of road barriers was outlined in Bologna, Italy. All the collected information was georeferenced in a Geographic Information System (GIS) environment and hence plotted in thematic maps for an easier analysis. In addition, compliance to the norm was verified. The research was tested to provide public authorities with an effective tool in the evaluation of maintenance activities and road safety policies.

Comparison of different methods to determine the sound reduction index R of walls

The laboratory method (ISO 10140-2:2021) is probably the most accurate method to determine the sound reduction index R of walls. Flanking noise (ISO 10848-1 and 4:2017) is almost fully eliminated in the laboratory setup whereas this is not the case for in situ measurements (ISO 10052:2021). The measurements are even more difficult for measurements in open air or in factory halls with mock-up setups. Manufactures of building elements, such as prefabricated walls, are interested in quick measurements of the sound reduction index R of their products. This paper compares the traditional laboratory measurements, the intensity method and the Sopranoise road barrier method (EN 1793-6) with the vibration velocity / sound pressure method (ISO 140-4:1998). Different setups were measured using different methods in laboratory and in open air. Most of the experiments were done with loudspeakers used as an excitation source, but some were also done with shakers and a tapping machine. The importance of the use of sound shielded accelerometers will be elucidated.

Measurement of bearing capacity of steel road barrier flange via Barkhausen noise emission

This paper reports about the bearing capacity of a steel road barrier flange and its non-destructive assessment via magnetic Barkhausen noise. Bearing capacity was investigated as a function of the variable degree of plastic straining accumulated in the flange. Plastic deformation was developed on the samples cut from the flange and loaded by uniaxial tension under different strain rates in order to model the dynamic behaviour of plastic deformation during the real collisions. The results of experiments demonstrate that the accumulation of plastic deformation expressed in terms of increasing dislocation density, and the corresponding hardness of the matrix, reduces the bearing capacity of the flange expressed in terms of notch toughness. This decrease is only gentle for the lower plastic strain and becomes steeper for higher strains. Barkhausen noise emission also drops down and MBN envelopes are shifted to higher magnetic fields along with increasing plastic straining as a result of increasing opposition of increasing dislocation density against domain walls motion. It was also found that MBN parameters strongly correlate with notch toughness and especially magnetic hardness is very sensitive for determination of the flange state not only under the high strain rates but also under the strong dynamic impacts as those expected in the high angle collisions. The study proposes the methodology in which the used flanges could be approved for their further use.

Intelligent German traffic sign and road barrier assist for autonomous driving in smart cities

Intelligent German traffic sign and road barrier assist for autonomous driving in smart cities

IMPROVING ROAD SAFETY ON THE NATIONAL ROAD NETWORK IN ROMANIA THROUGH PILOT SOLUTIONS

In recognition of outstanding work in the field of road safety, especially for the implementation of road safety pilot projects, N.C.R.I.A.-S.A. was declared the winner. The road safety pilot projects that have attracted the attention of the IRF, being a model to follow for all road administrations are: Roller Barriers; Impact attenuators; Road sector 2+1; Cable Road barriers; Illumination of dangerous sectors with light assemblies; Projects to increase road safety by creating elevated road crossings. The International Road Federation (IRF) encourages all companies and organizations in the road development sector to get involved in the awards program it grants, because by promoting innovative ideas a positive and motivating influence can be created. The National Company for Road Infrastructure Administration S.A, Traffic Safety Service participated in the "Find a Way Global Road Safety Award" organized by IRF. In this article, the road safety projects are presented, with their results and the road safety measures implemented by the national roads and highways administrator in Romania, so that other road administrations to be encouraged to implement as many road safety measures as possible.

Navigating Uncharted Territories: Stories of Pre-Retired Science Teachers Amid Emergency Remote Online Learning

The purpose of this qualitative inquiry was to explore the narratives of pre-retired Science teachers who are teaching remotely amid the global health crisis. It hopes to describe and elucidate the significant events, realizations, insights, and how the pandemic changed their stories as facilitators of learning. A Qualitative research design was employed in this study; specifically, it utilized the descriptive narrative approach to get the limited stories of the participants. The participants of the study consisted of four (4) pre-retired Science teachers, two of whom came from private schools and two came from public schools in Bacolod City. The participants were selected through purposive sampling. The data was gathered through a semi-structured interview questionnaire and focused group discussion (FGD). Three themes emerged regarding the stories of the participants, a.) Trials and Tribulations of Pre-retired Science Teachers in Crossing with three (3) sub-themes; Building the Ark Before it Starts to Rain, Hands Coated with Grease, and Changing Gears Manually. The second theme, b.) Involvement, Practices, and Role of Pre-retired Science Teachers with three (3) subthemes, Pre-retired Science Teachers as Drivers of Curriculum and Instruction, Curvy Roads Make a Skillful Driver and Overcoming Road Barriers and Practices in Teaching Science Online, and Lastly, Opportunities and Privileges in Teaching Amidst Pandemic with two (2) subthemes, Reinventing and Realigning the Wheels and Midway Cognizance. The study discovered that various issues and challenges primarily mark pre-retired teachers’ stories and encounters with emergency remote learning during a pandemic. Science teachers realized that acceptance, development, consideration, patience, passion for teaching, adequate instruction, and an open mind about emergency remote learning are all critical components for the effective implementation of emergency remote learning. Keywords: Pre-retired teachers, remote learning, narrative research, teaching

The application of high-grade steel to the road barrier design for the construction project cost efficiency

Steel is a construction material that has been used in the construction field for a long time, so we need to consider more about the quality and the grading. Meanwhile, the cost of steel is so high that it will also impact the implementation. On this occasion, Hutama Karya Group in the collaboration with PT Bhirawa Steel has done research and innovation to the High-Grade Steel Structure, especially for type 520 MPa reinforcing steel which includes the development of Tensile strength, Yield Strength, Elongation from the strength of the materials. High-Grade Steel will be a solution to the cost efficiency of construction. Nowadays, the usages are only permitted for the non-structural part based on the written requirement from National Standard in Indonesia (SNI 2847: 2019), even though the test requirements for structural needs are already fulfilled. The purpose of this study was to apply it to the road barrier design along one of the sections of the Trans-Sumatera Toll Road which has a total length of a section of 58 kilometres. The usage of High-Grade Steel has proven to reduce the total weight needs of the reinforcing bar which may cut the cost by around 26 percent for the Road Barrier design. This study may be one of the proofs of the cost-efficient use of High-Grade Steel materials. Therefore, in further study, the testing reference which has been included in the structural use of the high-grade steel can be the supporting reference to be included in the SNI.

Road guardrail beam made of natural stem (Stipa tenacissima L.) eco-composite: Impact energy absorption improvement by stems and pre-tensioning

Reducing accidents, deaths, and serious injuries is an objective to be achieved by every health and road authority. To avoid road leaving, rigid barriers or stretched cables are used at the edges of the roads. These structures are based on metallic materials. This paper presents an innovative structure based on a composite reinforced with natural esparto stems as road barriers absorbing shock energy. The structure is lightened and reinforced by tensioned cables to ensure the prestressing of the whole. Prestressing is a technique widely used in civil engineering but rarely in composites. To develop new crash beam barriers based on Epoxy/Alfa10% material, Charpy tests were conducted to determine the absorbed energy per section of material per weight. Knowing the energy to be absorbed, the section and weight of the barrier can be designed. In this paper, physical tests were conducted on solid, solid-compressed, perforated, and perforated-cable-reinforced specimens according to the ASTM E23-18 standard. The results show that the compression prestressing improves the Epoxy impact energy absorption by 37.22%. The Epoxy/Alfa10% composite compression prestressing improves the absorbed energy by 67.7%. The Epoxy/Alfa10% compressed, perforated, and reinforced by cables composites gives a better result than the raw Epoxy material, with a minimum improvement of 22.69% with respect to the ratio Resilience value of Charpy V-notch specimen (KCV)/weight. Reinforcement of holed samples with cables gives the best energy absorption results on all experimental tests for both materials with a value of 8.83 J. Finite element models calibrated on Aluminum to be predictive are developed for the four types of specimens.