scholarly journals Laboratory Methods for Assessing the Influence of Improper Asphalt Mix Compaction on Its Performance

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2476 ◽  
Author(s):  
Michał Wróbel ◽  
Agnieszka Woszuk ◽  
Wojciech Franus
Keyword(s):  
Weather Conditions ◽  
Void Content ◽  
Technological Parameters ◽  
The Road ◽  
Asphalt Mix ◽  
Negative Effect ◽  
Roller Compactor ◽  
Compaction Energy ◽  
On The Road ◽  
Pavement Construction

Compaction index is one of the most important technological parameters during asphalt pavement construction which may be negatively affected by wrong asphalt paving machine set, weather conditions, or the mix temperature. Presented laboratory study analyzes the asphalt mix properties in case of inappropriate compaction. The reference mix was designed for AC 11 S wearing layer (asphalt concrete for wearing layer with maximum grading of 11 mm). Asphalt mix samples used in the tests were prepared using Marshall device with the compaction energy of 2 × 20, 2 × 35, 2 × 50, and 2 × 75 blows as well as in a roller compactor where the slabs were compacted to various heights: 69.3 mm (+10% of nominal height), 66.2 mm (+5%), 63 mm (nominal), and 59.9 mm (−5%) which resulted in different compaction indexes. Afterwards the samples were cored from the slabs. Both Marshall samples and cores were tested for air void content, stiffness modulus in three temperatures, indirect tensile strength, and resistance to water and frost indicated by ITSR value. It was found that either insufficient or excessive level of compaction can cause negative effect on the road surface performance.

scholarly journals Fail to Yield? An Analysis of Ambulance Crashes in Taiwan

2021 ◽  
Vol 13 (3) ◽  
pp. 1566
Author(s):  
Rong-Chang Jou ◽  
Ming-Che Chao
Keyword(s):  
Public Education ◽  
Weather Conditions ◽  
Medical Emergency ◽  
Transportation Safety ◽  
Emergency Vehicle ◽  
The Road ◽  
Mnl Model ◽  
On The Road ◽  
Crash Injuries ◽  
The Relationship

Introduction—Medical emergency vehicles help patients get to the hospital quickly. However, there were more and more ambulance crashes on the road in Taiwan during the last decade. This study investigated the characteristics of medical emergency vehicle crashes in Taiwan from January 2003 to December 2016. Methods—The ordered logit (OL) model, multinominal logit (MNL) model, and partial proportional odds (PPO) model were applied to investigate the relationship between the severity of ambulance crash injuries and its risk factors. Results—We found the various factors have different effects on the overall severity of ambulance crashes, such as ambulance drivers’ characteristics and road and weather conditions. When another car was involved in ambulance crashes, there was a disproportionate effect on the different overall severity, as found by the PPO model. Conclusions—The results showed that male ambulance drivers and car drivers who failed to yield to an ambulance had a higher risk of severe injury from ambulance crashes. Ambulance crashes are an emerging issue and need further policies and public education regarding Taiwan’s ambulance transportation safety.

Enhanced Model for Continuous Dielectric-Based Asphalt Compaction Evaluation

2018 ◽  
Vol 2672 (26) ◽  
pp. 144-154 ◽  
Author(s):  
Kyle Hoegh ◽  
Shongtao Dai ◽  
Trevor Steiner ◽  
Lev Khazanovich
Keyword(s):  
Dielectric Constants ◽  
Void Content ◽  
Calibration Data ◽  
Stable Model ◽  
Asphalt Overlay ◽  
Longitudinal Joint ◽  
Asphalt Mix ◽  
Pavement Construction ◽  
Air Void ◽  
Air Void Content

The compaction of asphalt concrete significantly affects long-term pavement performance. Although coring provides a relatively accurate way of assessing in-place density at specific locations, the coverage of the assessment is limited, especially at longitudinal joint locations. This can be particularly problematic because it is difficult to identify problematic locations that are likely to fail prematurely using current compaction assessment methods. Ground penetrating radar (GPR) provides an attractive nondestructive testing alternative for evaluation of compaction quality, especially with recent significant improvements in the GPR technology for this specific application. However, assessment of the air void content of the asphalt mix from the GPR-measured dielectric constant of the surface requires conversion of dielectric variation to air void content variation, which is the subject of this paper. An alternative to the commonly used model is proposed, leading to more justifiable predictions for low values of dielectric constants. The proposed model was used to interpret data from a 7-mi long asphalt overlay construction project. The results of the interpretation as compared with the results obtained with the conventional model show an improvement on the stability of the prediction at low air void contents, especially when core calibration data are limited and uncertainty is considered. These results are promising in the direction of reducing field cores necessary to have a stable model providing continuous compaction assessment of new asphalt pavement construction.

scholarly journals Accurate whole-night sleep monitoring with dry-contact ear-EEG

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kaare B. Mikkelsen ◽  
Yousef R. Tabar ◽  
Simon L. Kappel ◽  
Christian B. Christensen ◽  
Hans O. Toft ◽  
...  
Keyword(s):  
High Performance ◽  
Well Being ◽  
Extensive Study ◽  
Sleep Monitoring ◽  
The Road ◽  
Scalp Eeg ◽  
Dry Contact ◽  
Negative Effect ◽  
On The Road

AbstractSleep is a key phenomenon to both understanding, diagnosing and treatment of many illnesses, as well as for studying health and well being in general. Today, the only widely accepted method for clinically monitoring sleep is the polysomnography (PSG), which is, however, both expensive to perform and influences the sleep. This has led to investigations into light weight electroencephalography (EEG) alternatives. However, there has been a substantial performance gap between proposed alternatives and PSG. Here we show results from an extensive study of 80 full night recordings of healthy participants wearing both PSG equipment and ear-EEG. We obtain automatic sleep scoring with an accuracy close to that achieved by manual scoring of scalp EEG (the current gold standard), using only ear-EEG as input, attaining an average Cohen’s kappa of 0.73. In addition, this high performance is present for all 20 subjects. Finally, 19/20 subjects found that the ear-EEG had little to no negative effect on their sleep, and subjects were generally able to apply the equipment without supervision. This finding marks a turning point on the road to clinical long term sleep monitoring: the question should no longer be whether ear-EEG could ever be used for clinical home sleep monitoring, but rather when it will be.

scholarly journals THE BITUMEN BATCHING SYSTEM'S MODERNIZATION AND ITS EFFECTIVE ANALYSIS AT THE ASPHALT MIXING PLANT

Transport ◽  
2010 ◽  
Vol 25 (3) ◽  
pp. 325-335 ◽  
Author(s):  
Justas Bražiūnas ◽  
Henrikas Sivilevičius
Keyword(s):  
Asphalt Concrete ◽  
Additive Model ◽  
Technological Parameters ◽  
Destructive Effect ◽  
The Road ◽  
Weighted Matrix ◽  
Bitumen Content ◽  
Before And After ◽  
On The Road ◽  
And Performance

Some particular aspects such as the improvement methods of technological parameters for hot bitu‐ men storage in a pipeline transport system, transportation and dosed supply to batch asphalt mixing plant (AMP) are evaluated in this paper. Bitumen in asphalt concrete binds together the material of mineral particles into a strong conglomerate of a complicated structure, capable of withstanding the destructive effect of vehicles and the factors on the road pavements. The optimal amount of bitumen determined by calculation and laboratory testing should be maintained in mix batches of hot‐mix asphalt (HMA) obtained from AMP mixer. In the periodic type of the asphalt concrete blender mass of the weighted matrix in the all merging batcher's tanks should correspond in percents equally in the HMA to the designed amount of the job‐mix formula (JMF). The bitumen batcher does not always weigh bitumen portions precisely. Their mass deviations from the amount determined by JMF and its variation impair HMA composition and performance. In addition,, an additive model for calculating the effect of factors causing the variance of bitumen content in the produced HMA mixture is presented in this current paper as well. The data on statistical evaluation of bitumen batcher's modernization performed at certain Lithuanian Enterprise are discussed. The differences in structures of reconstructed and not reconstructed bitumen batching systems (BBS) are analysed and methods of determining modernization effectiveness are presented. The effectiveness of BBS is analysed too, defining the deviations of bitumen content in subsamples, taken and extracted everyday for two seasons (before and after the batcher's modernization) of HMA mixture production from the value of JMF and comparing them to the values of tolerances. The analysis of column charts and histograms shows that the made modernization helped to increase the precision of supplying the required amount of bitumen to HMA mixture insignificantly. However, the control of BBS has been considerably increased.

scholarly journals Intelligent Accident Prevention in VANETs

2019 ◽  
Vol 8 (2) ◽  
pp. 2401-2405
Keyword(s):  
Road Safety ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Weather Conditions ◽  
Accident Prevention ◽  
Road Accidents ◽  
Human Errors ◽  
The Road ◽  
On The Road ◽  
Nearest Neighbour Classifier

Accident prevention has always been an important issue for governments and car manufacturers across the world. Roughly 1.5 million people are killed in road accidents annually in India. The primary causes of accidents are broken and weathered roads, hazardous weather conditions, as well as human errors such as over speeding, distracted driving, and not following road safety rules. The traffic police work hard to enforce strict rules and maintain accident-free roads, but this hasn’t proven to be efficient. A vehicular ad hoc network (VANET), as the name says, is a network consisting of nodes. These nodes depict vehicles on the road. This project aims to use this technology with K-Nearest Neighbour Classifier (KNN) to create a prototype of a system which can notify drivers of an impending accident caused by forward collisions, rear collision etc., thus enabling them to take immediate action and prevent it.

scholarly journals Research on Virtual Test of Automobile Automatic Emergency Braking System on Ice-Snow Road

2021 ◽  
Vol 261 ◽  
pp. 02065
Author(s):  
Xianchao Zhu ◽  
Sheng Chang ◽  
Bingtao Li ◽  
Hualei Lu
Keyword(s):  
Weather Conditions ◽  
Simulation Method ◽  
Time To Collision ◽  
The Road ◽  
Injury Reduction ◽  
Emergency Braking ◽  
Virtual Test ◽  
Braking Distance ◽  
On The Road ◽  
Basic Characteristics

In view of the severe weather conditions in cold regions, the basic characteristics and braking distance of ice snow covered pavement are analyzed. This paper uses the PreScan/CarSim/Simulink software co-simulation method to test the automatic emergency braking (AEB) system on ice-snow roads. Through the appropriate adjustment of the time to collision (TTC) threshold, the car makes automatic emergency braking on the road with low friction coefficient system can achieve the effect of collision avoidance and injury reduction.

scholarly journals Analysis of the distribution of the number of applications of the estimated load on the Federal roads during the year

2018 ◽  
Vol 5 (4) ◽  
Author(s):  
Vladimir Akulov ◽  
Artem Tiraturyan ◽  
Ilya Bodro ◽  
Anastasia Simakova ◽  
Marina Farnieva
Keyword(s):  
Traffic Flow ◽  
Statistical Processing ◽  
Weather Conditions ◽  
Design Stage ◽  
Traffic Intensity ◽  
Agricultural Industry ◽  
The Road ◽  
Calculated Load ◽  
On The Road ◽  
Favorable Weather

The article is devoted to the statistical processing of traffic intensity and composition of traffic flow obtained from the points of automated traffic intensity accounting for 2010-2018 in order to determine the distribution of the number of applications of the calculated load by months. The main source of information for statistical processing was the results of traffic accounting on highways M-1 «Belarus», a-107 MMK Mozhaisk-Volokolamsk highway, M-3 «Ukraine», M-4 «don», M-4 «don». The correct determination of the traffic intensity and composition of the traffic flow is an important task that allows you to make adequate decisions at the design stage of roads, namely to choose a road structure that can operate under load from the actual traffic flow for the entire service life. The authors calculated the total number of applications of the calculated load to the point on the surface of the coating, using the coefficients of reduction of vehicles to the calculated load of 115 kN. After calculating the total number of applications, the resulting value was divided by the number of days in the month in question. According to the data obtained, the total total number of applications of the calculated load at all points of accounting, by month, was found. The minimum values of the number of load applications are observed in winter (January, February, March), when the situation on the road deteriorates due to weather conditions. The values range from 4.75 % to 8 % for roads M-1 «Belarus», M-3 «Ukraine», M-4 «Don», M-4 «Don». The maximum values of the number of load applications observed in the warmer months (July, August, September, October), due to the fact that there are favorable weather conditions for recreation and the most active agricultural industry. The values range from 7.6 % to 11.3 % for the roads M-1 «Belarus», M-3 «Ukraine», M-4 «Don», M-4 «Don».

scholarly journals IDENTIFICATION OF INDICATORS OF INTERACTING INDUSTRIAL ENTERPRISE SUBSYSTEMS FOR ACHIEVING QUALITY MANAGEMENT PURPOSES

2021 ◽  
Vol 5 (12) ◽  
pp. 136-144
Author(s):  
O. Anikeeva ◽  
A. Ivahnenko ◽  
M. Storublev
Keyword(s):  
Asphalt Concrete ◽  
Weather Conditions ◽  
Poor Quality ◽  
Engineering Structures ◽  
Repair Work ◽  
The Road ◽  
Bitumen Emulsion ◽  
On The Road ◽  
Asphalt Concrete Pavement ◽  
The Impact

Highways are the most important component of country's economic development. They are a complex of engineering structures that are subject to various kinds of deformations during operation. The causes of premature defects are outdated technologies, poor quality materials, high traffic loads, and weather conditions. On average, after 2–3 years of the new road operation, pits, overflows, potholes, cracks, rutting occur on asphalt concrete pavement, its presence worsens the traffic conditions on the road and violates the unimpeded passage of cars. To extend the life cycle of a transport object, there are preventive measures that prevent the destruction of road surfaces. Such activities include regular maintenance and repair work. One of the effective measures is the use of road impregnation materials (RIM). Road-impregnation materials are used in case of need to prevent aging of the organic binder in the composition of asphalt concrete in the coating, as well as to reduce the impact of external factors. In this article, the influence of the basis of the impregnating material of two manufacturers on the indicators of the properties of asphalt concrete of various degrees of destruction is investigated. Among the considered impregnating compositions, solvent-based road impregnation materials proved to be the most effective. It has been established that the abrasive effect on samples of asphalt concrete significantly reduces the effectiveness of impregnating materials, especially based on bitumen emulsion.

scholarly journals STUDI ANALISA PERENCANAAN PERKERASAN LENTUR DAN RENCANA ANGGARAN BIAYA (PADA PROYEK JALAN RUAS JALAN TEMBELENGAN–DURJAN KABUPATEN SAMPANG)

2019 ◽  
Vol 2 (2) ◽  
pp. 235
Author(s):  
Mishbahul Aziz ◽  
Sigit Winarto ◽  
Yosef Cahyo Setianto Poernomo ◽  
Agata Iwan Candra
Keyword(s):  
Traffic Flow ◽  
Government Regulation ◽  
Flexible Pavement ◽  
The Road ◽  
Technical Requirements ◽  
Road Section ◽  
On The Road ◽  
Pavement Construction ◽  
The Cost ◽  
Pavement Thickness

There was a build-up of lumps of sand on the road, precisely Tambelang-Durjan. This build-up of sand chunks occurs because many of the piled sand hauling trucks that pass on the road is obstructed because the road section has been damaged (potholes) and is unfit for passage, resulting in obstruction of traffic flow. In addition, the width of the section is not in accordance with the technical requirements of the 2011 Government Regulation. Therefore, it requires a flexible pavement re-planning and a Cost Budget Plan for land transportation lines, so that motorist access is comfortable. Planning flexible pavement using Laston with a planning age of 10 years obtained flexible pavement thickness, namely 4 cm thick AC-WC, 6 cm thick AC-BC, and 40 cm of Upper Foundation Layers (LPA) with the estimated size of the Budget Plan The cost of the flexible pavement construction of Tambelang- Durjan of Sampang Regency with a length of 1,145 km in the amount of Rp 5,744,585,463.00Terjadi penumbukan bongkahan pasir urug tepatnya di ruas jalan Tambelangan-Durjan. Penumpukan bongkahan pasir ini terjadi karena banyak truk pengangkut bongkahan pasir urug tersebut yang melintas pada jalan itu terhambat karena ruas jalan mengalami kerusakan (berlubang) dan tidak layak dilalui, sehingga  yang mengakibatkan terhambatnya arus lalu lintas. Selain itu lebar ruas tidak sesuai dengan persyaratan teknis Peraturan Pemerintah tahun 2011. Oleh karena itu, memerlukan perencanaan ulang perkerasan lentur dan Rencana Anggaran Biaya untuk jalur transportasi darat supaya akses pengendara nyaman. Perencanaan perkerasan lentur menggunakan Laston dengan umur rencana 10 tahun didapatkan tebal perkerasan lentur yaitu AC-WC setebal 4 cm, AC-BC setebal 6 cm dan Lapis Pondasi Atas (LPA) setebal 40 cm dengan besar perkiraan Rencana Anggaran Biaya pembangunan perkerasan lentur ruas Tambelangan-Durjan Kabupaten Sampang sepanjang 1,145 km sebesar Rp 5.744.585.463,00.

scholarly journals Convective Мodel of Еmission Distribution on the Road Overpass Under Neutral Weather Conditions

2018 ◽  
Vol 0 (27) ◽  
pp. 23-31
Author(s):  
Olena Voloshkіna ◽  
Volodymyr Тrоfymоvych ◽  
Iryna Klimova ◽  
Roman Sipakov ◽  
Tetiana Tkachenko
Keyword(s):  
Weather Conditions ◽  
The Road ◽  
On The Road
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