scholarly journals Determination of Friction Performance of High Friction Surface Treatment Based on Alternative Macrotexture Metric

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6895
Author(s):  
Hua Zhao ◽  
Fulu Wei ◽  
Ce Wang ◽  
Shuo Li ◽  
Jie Shan
Keyword(s):  
Surface Treatment ◽  
Friction Surface ◽  
Surface Friction ◽  
Test System ◽  
Test Methods ◽  
Friction Test Methods ◽  
Profile Depth ◽  
Aggregate Loss ◽  
Friction Performance

Surface friction is currently the most common metric for evaluating the performance of high friction surface treatment (HFST). However, friction test methods such as the locked wheel skid tester (LWST) commonly provide a spot measurement. Large variations may arise in the LWST testing on curves. Based on 21 actual HFST projects, a study was performed to use a macrotexture metric, i.e., the mean profile depth (MPD) to evaluate HFST’s performance and improve its quality control (QC)/quality assurance (QA) procedures. The material properties were presented to understand the aspects of HFST. The method for calculating MPD was modified to account for the variations of macrotexture measurements. A vehicle-based test system was utilized to measure MPD periodically over an 18-month period since HFST installation. Statistical analysis was performed on the MPD measurements to identify the effects of influencing factors. Compared with the friction from LWST, MPD was equally effective in evaluating HFST performance. However, the use of MPD eliminated the errors as arisen in LWST testing and made it possible to detect surface distresses, including aggregate loss, delamination, and cracking. The expected overall MPD may be calculated by combining the MPD measurements made three months after installation at different HFST sites and used as a metric for evaluating HFST performance and QC/QA.

scholarly journals Investigation of Durability and Performance of High Friction Surface Treatment

2021 ◽  
Author(s):  
Fulu Wei ◽  
Ce Wang ◽  
Xiangxi Tian ◽  
Shuo Li ◽  
Jie Shan
Keyword(s):  
Surface Treatment ◽  
Friction Surface ◽  
Coefficient Of Thermal Expansion ◽  
Good Condition ◽  
Surface Friction ◽  
Loading Test ◽  
System Integrity ◽  
Chip Seal ◽  
Friction Performance ◽  
And Performance

The Indiana Department of Transportation (INDOT) completed a total of 25 high friction surface treatment (HFST) projects across the state in 2018. This research study attempted to investigate the durability and performance of HFST in terms of its HFST-pavement system integrity and surface friction performance. Laboratory tests were conducted to determine the physical and mechanical properties of epoxy-bauxite mortar. Field inspections were carried out to identify site conditions and common early HFST distresses. Cyclic loading test and finite element method (FEM) analysis were performed to evaluate the bonding strength between HFST and existing pavement, in particular chip seal with different pretreatments such as vacuum sweeping, shotblasting, and scarification milling. Both surface friction and texture tests were undertaken periodically (generally once every 6 months) to evaluate the surface friction performance of HFST. Crash records over a 5-year period, i.e., 3 years before installation and 2 years after installation, were examined to determine the safety performance of HFST, crash modification factor (CMF) in particular. It was found that HFST epoxy-bauxite mortar has a coefficient of thermal expansion (CTE) significantly higher than those of hot mix asphalt (HMA) mixtures and Portland cement concrete (PCC), and good cracking resistance. The most common early HFST distresses in Indiana are reflective cracking, surface wrinkling, aggregate loss, and delamination. Vacuum sweeping is the optimal method for pretreating existing pavements, chip seal in particular. Chip seal in good condition is structurally capable of providing a sound base for HFST. On two-lane highway curves, HFST is capable of reducing the total vehicle crash by 30%, injury crash by 50%, and wet weather crash by 44%, and providing a CMF of 0.584 in Indiana. Great variability may arise in the results of friction tests on horizontal curves by the use of locked wheel skid tester (LWST) due both to the nature of vehicle dynamics and to the operation of test vehicle. Texture testing, however, is capable of providing continuous texture measurements that can be used to calculate a texture height parameter, i.e., mean profile depth (MPD), not only for evaluating friction performance but also implementing quality control (QC) and quality assurance (QA) plans for HFST.

Laboratory and Field Evaluation of Single Layer and Double Layer High Friction Surface Treatments

2019 ◽  
Vol 2673 (2) ◽  
pp. 552-561 ◽  
Author(s):  
Shuo Li ◽  
Peiliang Cong ◽  
Demei Yu ◽  
Rui Xiong ◽  
Yi Jiang
Keyword(s):  
Double Layer ◽  
Friction Surface ◽  
Single Layer ◽  
Aggregate Size ◽  
Surface Friction ◽  
Field Evaluation ◽  
The United States ◽  
Aggregate Gradation ◽  
State Highway ◽  
Friction Performance

High friction surface treatment (HFST) has been proactively used as a solution to extreme friction demands at locations such as horizontal curves, ramps, bridge decks, and intersections. Considerable efforts have been made to evaluate the use of HFST across the United States (U.S.) The American Association of State Highway and Transportation Officials (AASHTO) has issued a provisional specification, i.e., AASHTO PP 79-14, to help state Departments of Transportation (DOTs) to successfully apply HFST. This paper presents a further effort made by the authors to evaluate and compare the friction performance and durability of single and double layer HFTS systems with calcined bauxite aggregate. The laboratory accelerated polishing was conducted to evaluate the effects of aggregate candidate gradations on the friction performance, such as friction coefficient and macrotexture mean profile depth (MPD), and to determine the aggregate gradation for field evaluation. Field evaluation was conducted on both single and double layer HFST systems using test strips under actual traffic polishing over a time period of nine months that covered an entire snow season. It was found that larger aggregate size tends to yield larger MPD, but larger MPD does not necessarily imply larger friction. The double layer HFST did not outperform the single layer HFST with respect to friction and durability. If the properties of calcined bauxite aggregate are precisely defined, either surface friction or MPD can solely be utilized as the frictional metric for quality assurance (QA) of HFST.

High Friction Surface Treatment Deterioration Analysis and Characteristics Study

2021 ◽  
pp. 036119812110296
Author(s):  
Cibi Pranav ◽  
Yi-Chang (James) Tsai
Keyword(s):  
Surface Treatment ◽  
Performance Measures ◽  
Friction Surface ◽  
Laser Scanning ◽  
Performance Monitoring ◽  
Performance Measure ◽  
Safety Performance ◽  
Test Track ◽  
Percentage Area ◽  
Aggregate Loss

High friction surface treatment (HFST) is used to improve friction on curved roadways, especially on curves that have a history of wet pavement crashes. Observations on the long-term performance monitoring of HFST sections at the National Center for Asphalt Technology (NCAT) Test Track showed friction (skid number, SN) dropped significantly at the end of service life of HFST, creating unsafe driving conditions. There is no clear, observed friction deterioration trend to predict the friction drop when using friction performance measures like SN. Therefore, there is an urgent need to explore and develop supplementary HFST safety performance measures (such as aggregate loss) that can correlate to friction deterioration and provide predictable, cost-effective, and easily measurable results. The objectives of this paper are to (i) analyze the correlation between HFST aggregate loss percentage area and friction value using a dynamic friction tester (DFT), and (ii) study the characteristics of HFST deterioration associated with aggregate loss, at the NCAT Test Track and at selected HFST curve sites in Georgia (using 2D imaging and high-resolution 3D laser scanning). Results show a strong correlation between HFST aggregate loss percentage area and DFT friction coefficient. Where friction measurement is used as the primary safety performance measure, it is recommended that HFST aggregate loss be used as a supplementary performance measure for monitoring the HFST safety performance deterioration. Aggregate loss can be easily identified by characteristics such as color and texture change. Preliminary texture analyses of 3D HFST surface profiles show lower mean profile depth (MPD) and ridge-to-valley depth (RVD) texture indicators can also identify loss of aggregate spots on HFST surface.

DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

2020 ◽  
pp. 19-26
Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar
Keyword(s):  
Mathematical Model ◽  
Surface Friction ◽  
Building Structures ◽  
Maximum Torque ◽  
Military Equipment ◽  
Military Vehicles ◽  
Force Magnitude ◽  
Vehicle Mobility ◽  
The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

Competency management of laboratory personnel using LIMS

2020 ◽  
Vol 10 (6) ◽  
pp. 636-641
Author(s):  
Konstantin S. Varaksin ◽  
◽  
Artem S. Makarov ◽  
Alexander Y. Lyapin ◽  
◽  
...  
Keyword(s):  
Quality Management ◽  
Management System ◽  
Quality Management System ◽  
Information Management System ◽  
Test System ◽  
Test Methods ◽  
Laboratory Activities ◽  
Resource Requirements ◽  
Laboratory Workers ◽  
Competence Test

The updated edition of the ISO/IEC 17025 standard introduced significant changes to the structure, terminology, resource requirements, processes, quality management system of testing and calibration laboratories. New requirements were established for the organization of laboratory activities – a process approach and risk-based thinking, which provides for a reduction in part of the prescriptive requirements and the introduction of requirements based on the analysis of the performance of actions. In accordance with GOST ISO IEC 17025-2019, the laboratory must authorize personnel to perform specific laboratory activities, as well as guarantee their competence. This article discusses the organization of the competence management system for the personnel of the laboratories of the organizations of Transneft system using the laboratory information management system (LIMS). The model of the process implementation has been described. It has been established that the competence test system allows you to regularly monitor the skills and knowledge of laboratory workers both in terms of the elements of the Quality Management System and in the applied measurement (test) methods. The personnel responsibility matrix implemented in LIMS regulates the powers and functionality of employees, ensuring that employees are allowed to perform work in accordance with their competence. The functions implemented in LIMS made it possible to automate the management of the competence of laboratory workers in accordance with the requirements of GOST ISO/IEC 17025-2019 and other regulatory documents.

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