scholarly journals REHABILITATION OF THE PAVEMENT OF FOUR ROUNDABOUTS BY MEANS OF THIN CONCRETE REINFORCEMENT ("THIN WHITETOPPING")

10.6036/9757 ◽  
2021 ◽  
Vol 96 (3) ◽  
pp. 250-253
Author(s):  
RUBEN LOPEZ CARRENO ◽  
SERGIO CARRASCON ORTIZ ◽  
ANTONIO AGUADO DE CEA ◽  
PABLO PUJADAS ALVAREZ
Keyword(s):  
Bearing Capacity ◽  
Road Surface ◽  
Heavy Vehicle ◽  
Heavy Vehicles ◽  
Bituminous Mixture ◽  
Detailed Design ◽  
National Road ◽  
Fuel Resistance ◽  
Concrete Reinforcement ◽  
Design And Construction

This article describes the design and construction of the structural rehabilitation of the bituminous pavement of four roundabouts by means of the arrangement of a 12 cm layer of vibrated concrete with fibres with very close joints (technique known as "thin whitetopping"). The roundabouts, which belong to the N-II National Road as it passes through La Jonquera (Spain), are subject to high levels of heavy vehicle traffic (IMDp > 4,000 heavy vehicles/day). In the project phase, the causes of deterioration of the original road surface were studied, its remaining bearing capacity was characterised and the thickness of concrete to be used was calculated. In the most damaged areas, the bituminous mixture was completely replaced by a lower quality concrete which was adhered to the concrete of the reinforcement by means of metal connectors. In addition, a detailed design of the transitions between the rehabilitated and the existing pavement and the arrangement of the joints was also carried out. Throughout the document, the different tasks carried out for the design and construction of the adopted solution are described in detail and, finally, design and construction recommendations are provided based on the results obtained. Keywords: Concrete, concrete bonding, Concrete with fibres, Reinforcement of pavements with concrete, Fuel resistance, Whitetopping.

scholarly journals Petrographic and Geotechnical Characteristics of Carbonate Aggregates from Poland and Their Correlation with the Design of Road Surface Structures

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2034
Author(s):  
Jerzy Trzciński ◽  
Emilia Wójcik ◽  
Mateusz Marszałek ◽  
Paweł Łukaszewski ◽  
Marek Krajewski ◽  
...  
Keyword(s):  
Road Surface ◽  
Surface Structures ◽  
Engineering Properties ◽  
Geological Engineering ◽  
Functional Relationships ◽  
Road Design ◽  
Geotechnical Characteristics ◽  
Design Calculations ◽  
Building Engineering ◽  
Design And Construction

The paper presents the basic problem related with practical application of carbonate rocks in construction: are carbonate aggregates produced from such rocks favorable for building engineering, particularly for road design and construction? To resolve this problem, (1) the geological-engineering properties of aggregates are presented, (2) the correlation between petrographic and engineering parameters is shown, and (3) a strict correlation between the geological-engineering properties and the freezing-thawing and crushing resistance is recognized. This knowledge has allowed to assess the usefulness of asphalt concrete (AC) made from dolomite and limestone aggregates in the design and construction of road surface structures. The petrography was characterized using optical microscopy and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscope (EDS). Engineering properties were determined in accordance with European and Polish norms and guidelines. Statistical and design calculations were performed using dedicated software. The petrographic properties, and selected physical and mechanical parameters of the aggregates, were tested to show their influence on the freezing–thawing and crushing resistance. Strong functional relationships between the water adsorption, and the freezing–thawing and crushing resistance have been observed. Aggregate strength decreased after saturation with increasing concentrations of salt solutions. Calculations of AC fatigue durability and deformation allow for reducing the thickness of the road surface structure by about 20% in comparison to normative solutions. This conclusion has impact on the economy of road design and construction, and allows for a rational utilization of rock resources, which contributes to sustainable development of the construction industry.

scholarly journals EVALUATING THE EFFECT OF HEAVY VEHICLES ON TRAFFIC PARAMETERS BY USING HEAVY VEHICLE FACTOR

2018 ◽  
Vol 6 (4) ◽  
pp. 95-104
Author(s):  
Parthkumar Patel ◽  
H.R. Varia
Keyword(s):  
Travel Time ◽  
Traffic Flow ◽  
Road Traffic ◽  
Freight Transport ◽  
Heavy Vehicle ◽  
Mixed Traffic ◽  
Heavy Vehicles ◽  
Highway Traffic ◽  
Ideal Situation ◽  
The Impact

Safe, convenient and timely transportation of goods and passengers is necessary for development of nation. After independence road traffic is increased manifold in India. Modal share of freight transport is shifted from Railway to roadways in India. Road infrastructures continuously increased from past few decades but there is still need for new roads to be build and more than three forth of the roads having mixed traffic plying on it. The impact of freight vehicles on highway traffic is enormous as they are moving with slow speeds. Nature of traffic flow is dependent on various traffic parameters such as speed, density, volume and travel time etc. As per ideal situation these traffic parameters should remain intact, but it is greatly affected by presence of heavy vehicle in mixed traffic due to Svehicles plying on two lane roads. Heavy vehicles affect the traffic flow because of their length and size and acceleration/deceleration characteristics.  This study is aimed to analyse the impact of heavy vehicles on traffic parameters.

scholarly journals Comparative Analysis of Effects of Heavy Vehicles on Roads in Southern and Northern Nigeria

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
C. C. Osadebe ◽  
H. A. Quadri
Keyword(s):  
Northern Region ◽  
Design Guidelines ◽  
Traffic Volume ◽  
Southern Region ◽  
Heavy Vehicle ◽  
Heavy Vehicles ◽  
Passenger Cars ◽  
The Road ◽  
Equivalency Factors ◽  
On The Road

The prevalence of flexible pavement deterioration in the country has been adduced largely by highway researchers to trucks or heavy vehicles carrying much in excess of permitted legal limits. This study investigated levels of deterioration of Abuja-Kaduna-Kano road (Northern region) and Port Harcourt-Enugu road (Southern region) caused by heavy vehicles through a 14 day traffic counts conducted at 5 strategic points each in the Northern and Southern regions. Traffic data generated were analyzed with AASHTO Design Guidelines (1993) to evaluate Equivalent Single Axle Loads (ESALs) and Vehicle Damage effects on the road. The Traffic Volume, Average Daily Traffic (ADT), and Heavy Vehicle per day (HV/day) were estimated to be 2,063,977; 147,427; and 12,246 respectively in the Northern region, while in the Southern region they were estimated to be 750,381; 53,670; and 20,951 respectively. Motorcycles, Passenger cars, Mini-buses/Pick-ups, and Heavy vehicles constitute 18.7%, 49.7%, 23.3% and 8.31% of the total traffic volume respectively in the Northern region while in the South they constitute 4.6%, 30.1%, 26.2% and 39.1% respectively. ESALs were estimated according to AASHTO Design Guidelines in the Northern and Southern regions as 547,730 and 836,208 respectively. An average Load Equivalency Factors (LEFs) of 3.43 and 3.02 were estimated for each heavy vehicle plying the Northern and Southern roads respectively and this could explain some failures (alligator cracks, potholes, depressions, linear or longitudinal cracks along the centre line amongst others) inherent on the road.

scholarly journals Study on Pre-Warning Method of the Lateral Security of Heavy Vehicle in Deteriorative Weather

2014 ◽  
Vol 8 (1) ◽  
pp. 292-296
Author(s):  
Zhi-Guo Zhao ◽  
Min Chen ◽  
Nan Chen ◽  
Yong-Bing Zhao ◽  
Xin Chen
Keyword(s):  
Friction Coefficient ◽  
Critical Speed ◽  
Warning System ◽  
Heavy Vehicle ◽  
Heavy Vehicles ◽  
Core Technology ◽  
Road Friction ◽  
Turning Radius ◽  
Safety Features ◽  
Road Friction Coefficient

The lateral security of heavy vehicle in deteriorative weather is one of the main causes of accidents of vehicles on roads. Road safety has become a subject of great concern to institutions of higher education and scientific research institutions. There are important theoretical and practical significances to explore applicable and effective lateral safety warning methods of heavy vehicles. One of the purposes of this paper is to provide a good theoretical basis for the core technology of heavy vehicle safety features for our country's independent research and development. Aiming at the issue of lateral security of heavy vehicle for road conditions in deteriorative weather, this paper constructs the framework of the lateral security pre-warning system of heavy vehicles based on cooperative vehicle infrastructure. Moreover, it establishes vehicle lateral security statics model through analysis of the force of the car in the slope with section bending and states the parameters of vehicles for no rollover. The side slip is indexed to calculate critical speed of vehicles in a bend. This paper also analyzes the influence of road friction coefficient, the road gradient and the turning radius on the lateral security of the vehicle with critical speed on the asphalt pavement with surface conditions ranging from wet, dry, snowing or icy. The calculation results show that the bad weather road conditions, road friction coefficient and turning radius have obvious influence on the lateral security critical speed. Experimental results indicate that the critical speed error warning is within 4% and it meets the design requirements.

Analysing the Performance of a Fuzzy Lane Changing Model Using Data Mining

2015 ◽  
pp. 1540-1566
Author(s):  
Sara Moridpour
Keyword(s):  
Traffic Safety ◽  
Traffic Simulation ◽  
Heavy Traffic ◽  
Heavy Vehicle ◽  
Heavy Vehicles ◽  
Passenger Cars ◽  
Lane Changing ◽  
Microscopic Traffic Simulation ◽  
Traffic Characteristics ◽  
Using Data

Heavy vehicles have substantial impact on traffic flow particularly during heavy traffic conditions. Large amount of heavy vehicle lane changing manoeuvres may increase the number of traffic accidents and therefore reduce the freeway safety. Improving road capacity and enhancing traffic safety on freeways has been the motivation to establish heavy vehicle lane restriction strategies to reduce the interaction between heavy vehicles and passenger cars. In previous studies, different heavy vehicle lane restriction strategies have been evaluated using microscopic traffic simulation packages. Microscopic traffic simulation packages generally use a common model to estimate the lane changing of heavy vehicles and passenger cars. The common lane changing models ignore the differences exist in the lane changing behaviour of heavy vehicle and passenger car drivers. An exclusive fuzzy lane changing model for heavy vehicles is developed and presented in this chapter. This fuzzy model can increase the accuracy of simulation models in estimating the macroscopic and microscopic traffic characteristics. The results of this chapter shows that using an exclusive lane changing model for heavy vehicles, results in more reliable evaluation of lane restriction strategies.

Spring Load Restrictions in Finland: Current Policy and Research Implications

1998 ◽  
Vol 1615 (1) ◽  
pp. 29-31
Author(s):  
Jukka Isotalo
Keyword(s):  
Research Programme ◽  
Road Maintenance ◽  
Current Policy ◽  
Heavy Vehicles ◽  
Minimum Standard ◽  
Maximum Weight ◽  
Frost Action ◽  
Heavy Trucks ◽  
Restriction Policy ◽  
National Road

Roads in Finland are exposed to seasonal strength variation. Because of industrial policy, the maximum weight of heavy trucks is 60 metric tons all year. The policies applied by the Finnish National Road Administration (Finnra) to mitigate the effects of seasonal road strength variations on public roads, and the current research on the topic in Finland, are investigated. It has been estimated that the annual cost of road repairs because of spring damages is about $10 million under the present load restriction policy. The costs for road repairs would be $35 million without restrictions. The annual additional cost for all heavy transport is estimated at $15 million. An internal Finnra survey revealed that $80 million to $100 million is needed to repair all known frost-susceptible road sections. Finnra load restrictions are intended to prevent damage to roads by heavy vehicles during spring thaw. The restrictions will reduce and possibly eliminate increases in annual road maintenance costs. On the other hand, the restrictions will allow a minimum standard for vital transport. Finnra’s Road Structures Research Programme (TPPT) studies improvements in the durability, strength, and economy of road structures. A key part of the TPPT project concerns problems associated with frost, especially durability against frost action. The most important factors of frost action on roads are the freezing index, duration of frost and thaw seasons, surface temperature, and ground water level. Methods for testing and calculating frost effects are discussed, as are the questions that must be answered before more precise models can be published.

Benchmark Investigation of Dynamics Models for Design Optimization of Articulated Heavy Vehicles

2013 ◽  
Author(s):  
Md Manjurul Islam ◽  
Yuping He
Keyword(s):  
Design Optimization ◽  
Software Package ◽  
Eigenvalue Analysis ◽  
Heavy Vehicle ◽  
Tire Model ◽  
Heavy Vehicles ◽  
Plane Model ◽  
Motion Modes ◽  
Simulation Results ◽  
Dynamics Models

This paper represents validation of yaw plane and yaw-roll models of a tractor/semitrailer combination with TruckSim software package. A linear 3 degree-of-freedom (DOF) yaw-plane model and a linear 5 DOF yaw-roll model of tractor/semitrailer have been generated, compared and evaluated. This paper investigates the applicability of vehicle models with linear tire model. The models of the articulated heavy vehicle (AHV) yield excellent simulation results which are validated by comparing the simulation results obtained from TruckSim. This paper also includes eigenvalue analysis of the models to estimate their unstable motion modes. Benchmark comparison of the models has been performed to investigate the fidelity, complexity and applicability.

Study on Diseases of Multi-Box Girder Bridge

2012 ◽  
Vol 446-449 ◽  
pp. 1182-1185
Author(s):  
Wen Liang Qiu ◽  
Cai Liang Huang ◽  
Zhao Yi Chen
Keyword(s):  
Bearing Capacity ◽  
Box Girders ◽  
Load Bearing Capacity ◽  
Box Girder ◽  
Load Bearing ◽  
Large Load ◽  
Torsion Rigidity ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Design And Construction

Because the multi-box girder bridge has many advantages, such as large torsion rigidity, large load-bearing capacity, stability, fine appearance, good applicability and convenient construction, it is widely used in China. But for the defection existing in design and construction, many box girders have serious diseases. Aiming at the diseases of a viaduct bridge, the causes of diseases are analyzed and the enforcement method is proposed in this paper. The study shows that, though the box girders have large torsion rigidity, the diaphragms are designed necessarily to enhance the transversal connection between the box girders, to make them bear the loads together, to reduce their stresses and deformation, and to reduce the stresses of deck too.

Issues in Heavy Vehicles

1993 ◽  
Vol 37 (9) ◽  
pp. 579-579
Author(s):  
F. Renae Bowers-Carnahan ◽  
Rhonda Kinghorn ◽  
Alvah Bittner ◽  
Syd Reynolds ◽  
Anne-Marie Feyer ◽  
...  
Keyword(s):  
Human Factors ◽  
Heavy Vehicle ◽  
Heavy Vehicles ◽  
Driver Fatigue ◽  
Long Distance ◽  
Fitness For Duty ◽  
Safety Issues ◽  
Technological Advances ◽  
Operational Practices ◽  
Operational Issues

The heavy vehicle industry includes medium-duty trucks, heavy-duty trucks, and buses. Vehicle size, driver location relative to the road, and duration of time in the vehicle distinguish heavy vehicles from the passenger car and light truck industry. During the past decade, the industry has been changing. Technological advances, as well as political, economic, and cultural forces, have combined to create a new environment. The driver has become more important in this new environment. A driver shortage and safety issues have heightened the interest in human factors and ergonomics in the heavy vehicle industry. The purpose of this symposium is to highlight some of the current human factors research in the field of heavy vehicles. While there are many possible topics to discuss, the first two papers will address vehicle design issues and the second two papers will address operational issues. Ms. Kinghorn will discuss a technique to estimate the current population of US Truck Drivers. She proposes that some of the shortcomings of the available data, such as changes in the population over the last decade and dimensions for which no data are available, can be overcome by estimating the current truck driver population from data on the general population. Mr. Reynolds will discuss the discrepancies observed between a design eyellipse location and actual driver eye locations in a small exploratory study. He will describe the primary contributor to the discrepancy, the H-point, and suggest several other potential contributors. Ms. Feyer will discuss a study on the effects of operational practices on driver fatigue. She will compare and contrast the operational practices of various segments of the long distance passenger and freight hauling industries. Her results indicate that different strategies must be applied to the passenger and freight industries to combat fatigue, even though the causes of fatigue are the same. Ms. Freund is from the US Federal Highway Administration's Office of Motor Carriers. She will discuss their plans for research concerning truck and bus driver operational regulation. Specific areas that are of interest include proficiency testing, fitness for duty, and substance abuse. She will elaborate on the program, addressing driver fatigue and loss of alertness.

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