The Superpave Gradation Restricted Zone and Performance Testing With the Georgia Loaded Wheel Tester

1997 ◽  
Vol 1583 (1) ◽  
pp. 106-111 ◽  
Author(s):  
Donald E. Watson ◽  
Andrew Johnson ◽  
David Jared
Keyword(s):  
High Performance ◽  
Performance Testing ◽  
Mix Design ◽  
Design System ◽  
Department Of Transportation ◽  
Natural Sand ◽  
Aggregate Gradation ◽  
Actual Field ◽  
And Performance ◽  
Highway Research

Guidelines for the new hot-mix asphalt design system, Superpave, were developed under the Strategic Highway Research Program. One of the most controversial components of this system is the aggregate gradation restricted zone. This restricted zone was adopted as a gradation specification primarily to deter the use of high levels of natural sand in high-performance mixes. By designing mixes with gradations that avoid the restricted zone (i.e., limit natural sand), the internal strength provided by internal friction could be improved. Some agencies question the validity of the restricted zone. The specified gradations of many current mixes contain bands that enter the restricted zone, but the mixes have performed well for years in actual field conditions. The Georgia Department of Transportation (GDOT) currently specifies several standard mixes with gradations that enter the restricted zone and still perform well. These high-performance mixes contain good quality, 100 percent manufactured aggregates and no natural sand. GDOT recommends that the Georgia loaded wheel tester or some other proof tester be incorporated into the mix design process to screen mixes before rejecting them solely because their combined gradation enters the restricted zone. If mixes having combined gradations that enter the restricted zone are categorically rejected, mixes that are economical for the purpose intended may be rejected in the process.

Initial Approach to Performance (Balanced) Mix Design: The Virginia Experience

2019 ◽  
Vol 2673 (2) ◽  
pp. 335-345 ◽  
Author(s):  
Stacey D. Diefenderfer ◽  
Benjamin F. Bowers
Keyword(s):  
Performance Testing ◽  
Performance Criteria ◽  
Mix Design ◽  
Department Of Transportation ◽  
Innovative Methods ◽  
Asphalt Mix ◽  
Performance Additives ◽  
Virginia Department ◽  
Selection Of

Performance mix design (PMD) of asphalt mixtures, often referred to as balanced mix design, is a design methodology that incorporates performance testing into the mix design process. The Virginia Department of Transportation (DOT), like many owner agencies, is interested in ways to specify asphalt mix designs better in an effort to make its roadway network more sustainable, longer lasting, and more economical. By adding performance criteria through a PMD framework, that goal can be achieved. Further, a PMD framework should allow for the development of new, innovative methods to increase pavement recyclability, new performance additives, and other means to enhance pavement performance. This paper provides details and documentation of the approach being taken by the Virginia DOT in their efforts to develop a PMD specification. Aspects of development presented include PMD method options, selection of performance tests, and determination of acceptance criteria. A discussion about validating specifications with in-service performance data and addressing quality control and quality assurance is also provided. Although additional work is needed for full development and implementation, the methodology being applied has been found to provide useful outcomes for the Virginia DOT even in the initial stages of development.

Experimental Research and Performance Testing of Fe-Based Composite Plating

2011 ◽  
Vol 221 ◽  
pp. 364-368 ◽  
Author(s):  
Ping Fu ◽  
Cheng Zhao ◽  
Hua Tian
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
High Performance ◽  
Composite Coatings ◽  
Performance Testing ◽  
Optimum Process ◽  
Ferrous Chloride ◽  
Composite Plating ◽  
Micro Cracks ◽  
And Performance

By using self-made asymmetric AC - DC power supply and adding SiC in ferrous chloride bath, the high performance Fe-SiC iron-based composite coatings were prepared by electrodeposition method. The effect of Phase, composition and SiC particle content on the surface morphology, structure, hardness, wear resistance and corrosion resistance of Fe-SiC composite coatings were studied. The process parameters of Fe-SiC composite plating were optimized. The results showed that the micro-cracks in composite coatings would reduced and the hardness, wear resistance and corrosion resistance will increased by adding SiC particles under the condition of optimum process.

Hydrogen Peroxide-Based Gas Generator Design and Performance Testing as an Aircraft Emergency Power Unit

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
Gyaebyung Yang ◽  
Daejong Park ◽  
Chun Taek Kim ◽  
Sejin Kwon
Keyword(s):  
Hydrogen Peroxide ◽  
Power Unit ◽  
High Performance ◽  
Performance Testing ◽  
Gas Generator ◽  
H2o2 Decomposition ◽  
New Family ◽  
Emergency Power ◽  
And Performance ◽  
Generator Design

Hydrazine monopropellant is often used with a spontaneous catalyst a high-performance aircraft emergency power unit (EPU) and in aerospace propulsion; however, it is toxic and requires special handling. A hydrogen peroxide (H2O2)-based gas generator, which is suitable for a new family of environmentally friendly monopropellants and is a substitute for toxic hydrazine in EPUs, is introduced in this study. A MnO2/Al2O3 catalyst for H2O2 decomposition, superior to silver catalysts at normal starting and reactivity capabilities, was selected and developed. The performance tests of coupling the gas generator with a turbocharger showed acceptable results for an aircraft EPU with decomposition above 90%, 37 kW maximum turbine output power, and a maximum starting delay of 1.2 s during normal starting operation. The gas generator also demonstrated satisfactory performance during repeated pulse operation at a pulse duration of 3 s and 60 s under various output conditions.

The Mix Design Method and Performance for C60 Concrete Poles with High Strength, Impermeability and Frost Resistance

2014 ◽  
Vol 1035 ◽  
pp. 161-165
Author(s):  
Hai Jun Xing ◽  
Xin Tuo Hou ◽  
Bin Rong Zhu ◽  
Zi Fu Zhang ◽  
Zhen Fu Li
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Design Method ◽  
High Strength ◽  
Mix Design ◽  
Mineral Admixtures ◽  
Concrete Mix ◽  
And Performance ◽  
The Impact ◽  
The Relationship

In corrosive soils areasand extremely cold regions,high performance is required inthe impermeability and frost resistanceof concrete poles. In this paper, the mix design of C60 high performance concrete and the relationship between mix parameters and performance is studied and analyzed ,and the influence of the water-cement ratio, the amount of cementation materials, the mineral admixtures and other factors on High Performance Concrete is discussed, as well as the impact of different admixtures for concrete. According to the analysis results, the concrete mix is designed and used in practice.

Oil Free 8 kW High-Speed and High Specific Power Turbogenerator

2014 ◽  
Author(s):  
Hooshang Heshmat ◽  
James F. Walton ◽  
Andrew Hunsberger
Keyword(s):  
High Speed ◽  
High Performance ◽  
Modular Design ◽  
Preliminary Test ◽  
Specific Power ◽  
Design System ◽  
Turbine Engine ◽  
Foil Bearings ◽  
High Specific Power ◽  
And Performance

In the paper the authors will present the design and preliminary test results for a high specific power (i.e., kW/kg) fully integrated and completely oil-free gas turbine driven electric generating system that operates with commercially available heavy fuel. The oil-free, high-speed micro-turboalternator system achieves high specific power through operating speeds to 180,000 rpm and the use of compliant foil bearings, high performance compressor and turbine and a permanent magnet alternator. The high operating temperatures and speeds require that oil-free compliant foil bearings be used and that the alternator section be isolated from the turbine engine portion of the system. The selected modular design approach, including compressor and turbine aerodynamic design, system thermal management issues and the corresponding impact on rotor bearing system dynamics, will all be presented. The paper concludes with a presentation of preliminary testing results showing stable full speed operation and peak power generated. Data obtained compares well with design predictions both from a rotordynamic and with regard to the cycle efficiency and performance. Conclusions regarding the ability to scale the technology to even smaller systems will also be presented.

Developing QC/QA Specifications for Hot Mix Asphalt Concrete in Illinois

1997 ◽  
Vol 1575 (1) ◽  
pp. 66-74 ◽  
Author(s):  
Arti Patel ◽  
Marshall Thompson ◽  
Eric Harm ◽  
William Sheftick
Keyword(s):  
Quality Management ◽  
Asphalt Concrete ◽  
Hot Mix Asphalt ◽  
Management Program ◽  
Department Of Transportation ◽  
Certification Program ◽  
Aggregate Gradation ◽  
Percent Increase ◽  
And Performance

The Illinois Department of Transportation (IDOT) has recently undertaken a quality management program to improve the quality of construction, allow more innovation, and reduce IDOTs management of industry construction programs. The Asphalt Concrete (AC) Quality Control/Quality Assurance (QC/QA) program is a significant part of this quality management program. IDOT accredits the success of the AC QC/QA program to gradual implementation and contractor and industry involvement. In 1991, four projects were constructed under a newly developed QC/QA specification. After reviewing and evaluating feedback from the contractors and IDOT personnel, the specification was revised for use on 1992 projects. In 1992, IDOT let 30 QC/QA projects, and in 1993, 65 QC/QA projects. In 1994 and 1995, most AC projects containing over 225 metric tons (250 tons) of hot-mix asphalt (HMA) were designated as QC/QA projects. In conjunction with this effort on AC quality, an aggregate certification program was implemented. The program ensures that aggregate gradation is highly controlled and is acceptable for incorporation into the mixture. Training programs for contractor QC and aggregate certification were also implemented. Analysis of the data indicates an increase in uniformity of the HMA, potentially leading to a 15 percent increase in fatigue life. IDOT is now examining the implications of developing end-result and performance-related specifications (ERS/PRS) for the AC QC/QA program. In the summer of 1996, one QC/QA project was shadowed and evaluated based on newly developed ERS/PRS.

Trace nanoanalysis

1994 ◽  
Vol 52 ◽  
pp. 940-941
Author(s):  
D. E. Newbury ◽  
R. D. Leapman
Keyword(s):  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Detection Efficiency ◽  
Volume Element ◽  
And Performance ◽  
Trace Constituents ◽  
Secondary Ion ◽  
Concentration Levels ◽  
Structure Properties

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).

Digitalization system of ancient architecture decoration art based on neural network and image features

2020 ◽  
pp. 1-12
Author(s):  
Wu Xin ◽  
Qiu Daping
Keyword(s):  
Neural Network ◽  
Construction Industry ◽  
Three Dimensional ◽  
Performance Testing ◽  
Image Features ◽  
Three Dimensional Model ◽  
Performance Effect ◽  
Data Process ◽  
And Performance ◽  
Construction Mode

The inheritance and innovation of ancient architecture decoration art is an important way for the development of the construction industry. The data process of traditional ancient architecture decoration art is relatively backward, which leads to the obvious distortion of the digitalization of ancient architecture decoration art. In order to improve the digital effect of ancient architecture decoration art, based on neural network, this paper combines the image features to construct a neural network-based ancient architecture decoration art data system model, and graphically expresses the static construction mode and dynamic construction process of the architecture group. Based on this, three-dimensional model reconstruction and scene simulation experiments of architecture groups are realized. In order to verify the performance effect of the system proposed in this paper, it is verified through simulation and performance testing, and data visualization is performed through statistical methods. The result of the study shows that the digitalization effect of the ancient architecture decoration art proposed in this paper is good.

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