The Measurement of Thickness and Model Prediction of Hot Asphalt Mixture in the Rolling Compacting Process

2012 ◽  
Vol 204-208 ◽  
pp. 1706-1714 ◽  
Author(s):  
Xiao Chen ◽  
Jian Long Zheng
Keyword(s):  
Quality Control ◽  
Temperature Field ◽  
Deformation Theory ◽  
Asphalt Mixture ◽  
Forecast Model ◽  
Test Methods ◽  
Temperature Fields ◽  
Temperature Changes ◽  
Thickness Prediction ◽  
Measurement Of Thickness

The thickness test and models prediction methods and rheological deformation theory have an important impact on quality control in the process of hot asphalt mixture field rolling compaction. DSL30 leveling instrument are used to measure the thickness in the process of hot asphalt mixture. Pt100 and Paperless Recorder are joined to test the temperature field and results of compaction thickness and temperature changes are obtained, and the model is established for mixture rheological deformation theory and compaction thickness prediction. The results shows that: by using the thickness and temperature field test methods, relevant data of hot asphalt mixture can be gained accurately, viscoplastic rheological theory correctly reflects its deformation behavior and the thickness forecast model can efficiently show the mixture layer. In this way, new methods are provided for the asphalt pavement quality control, rheological theory and temperature fields testing.

scholarly journals Non-Uniform Temperature Fields and Effects of Steel Structures: Review and Outlook

2020 ◽  
Vol 10 (15) ◽  
pp. 5255
Author(s):  
Wucheng Xu ◽  
Deshen Chen ◽  
Hongliang Qian
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Longwave Radiation ◽  
Steel Structures ◽  
Test Methods ◽  
Temperature Fields ◽  
Future Research ◽  
Uniform Temperature ◽  
Uniform Temperature Field ◽  
Correct Understanding

Due to the dynamic coupling effects of solar radiation, longwave radiation, convective heat transfer, shadows, and other factors, the temperature field and effect of steel structures are significantly non-uniform, differing from traditional concepts that regard the temperature variation of steel structures as a slow and uniform progress. This difference can hinder the correct understanding of the thermal behavior of steel structures and ignore some potential safety hazards. This paper provides a review of the studies for the non-uniform temperature field and effect of steel structures, and presents some outlooks on future developments on the basis of the current research situation. A summary of research on the temperature field and effect of space structures, bridges and radio telescopes initially establishes the basic cognitive framework for this field. In addition, then, the basic principles of the numerical simulation of temperature fields are introduced through heat transfer mechanism, and the experimental test methods of temperature and its effects are described based on typical test cases. Finally, with a view to the future, some suggestions and opinions are provided in consideration of deficiencies in the current research status. This paper hopes to provide some valuable references for future research in this field through research summary, method introduction and outlook.

Study on Temperature Field of Low Heat Accumulation Asphalt Concrete Pavement

2011 ◽  
Vol 97-98 ◽  
pp. 108-113 ◽  
Author(s):  
Zhen Zhen Li ◽  
Jian Guang Xie
Keyword(s):  
Temperature Field ◽  
Asphalt Concrete ◽  
Marked Effect ◽  
Asphalt Mixture ◽  
Test Methods ◽  
Temperature Data ◽  
Heat Accumulation ◽  
Powder Specimen ◽  
Concrete Temperature ◽  
Asphalt Concrete Pavement

Experimental results showed that low heat accumulation asphalt mixture had a marked effect on the reduction of surface temperatures. However changes in temperature over the test methods were not thoroughly studied. In the process of test, LJ infrared powder is used to prepare for making the content of 6% asphalt mixture specimen. Several temperature data of infrared powder specimen were compared with the data of ordinary specimen. Each number was compared and analyzed. At last, concrete temperature variation discipline of the temperature field was found.

Indirect Tensile Test (IDT) to Determine Asphalt Mixture Performance Indicators during Quality Control Testing in New Jersey

2018 ◽  
Vol 2672 (28) ◽  
pp. 394-403 ◽  
Author(s):  
Thomas Bennert ◽  
Edwin Haas ◽  
Edward Wass
Keyword(s):  
Quality Control ◽  
Tensile Test ◽  
Asphalt Mixture ◽  
Performance Testing ◽  
Fatigue Cracking ◽  
Test Methods ◽  
Mixture Design ◽  
Indirect Tensile Test ◽  
Quality Control Testing ◽  
Indirect Tensile

In recent years, there has been a growing interest in incorporating performance testing during the mixture design and quality control testing of asphalt mixtures. The move toward utilizing performance related specifications (PRS) and balanced mixture design concepts have pushed the need for asphalt mixture performance testing to the forefront. Numerous researchers have proposed a variety of laboratory tests that have showed promise at predicting asphalt mixture performance, yet most of these test methods are never adopted due to a number of issues often cited by the asphalt industry: (1) equipment cost; (2) equipment/test method complexity; and (3) time/labor effort required. The research presented here summarizes the effort to evaluate the indirect tensile test (IDT) as a potential performance indicator for hot-mix asphalt that can be easily utilized during quality control testing at an asphalt plant. Utilizing the same test equipment and basic procedure, both high-temperature rutting and intermediate-temperature fatigue cracking can be evaluated in a timely manner. Comparison testing to more standardized and accepted rutting and fatigue cracking test methods have shown excellent agreement, indicating that the suite of IDT tests have potential for adoption within a quality control testing program. Examples of criteria are given utilizing the New Jersey Department of Transportation’s (NJDOT) PRS.

Technology of Temperature Measurement in Concrete Bridge Pier

2012 ◽  
Vol 193-194 ◽  
pp. 770-775
Author(s):  
Yun Fang Wu ◽  
Zhi Yong Zhang
Keyword(s):  
Temperature Field ◽  
Temperature Measurement ◽  
Measurement Accuracy ◽  
Temperature Sensors ◽  
Test Methods ◽  
Temperature Fields ◽  
Paper Briefly ◽  
Advantages And Disadvantages ◽  
High Measurement ◽  
Section Model

In order to accurately get the concrete pier temperature field, this paper briefly introduces the types, advantages and disadvantages, development of temperature sensors and the composition, function and measurement accuracy of LTM-8663 intelligent temperature monitoring system. The system has high measurement precision, so we can measure the temperature field by it. In order to certify the rationality of test methods, taking a concrete pier section model as an example, we use the system to measure its sunshine temperature fields in different ways of embedding sensor. According to the comparative analysis of sunshine temperature fields measured in pier section model, we get useful conclusions and recommendations to be provided references for the concrete temperature measurement in piers and other structures.

Animal Models and Alternatives in the Quality Control of Vaccines: Are In Vitro Methods or In Vivo Methods the Scientific Equivalent of the Emperor's New Clothes?

1995 ◽  
Vol 23 (1) ◽  
pp. 61-73
Author(s):  
Coenraad Hendriksen ◽  
Johan van der Gun
Keyword(s):  
Quality Control ◽  
Test Methods ◽  
In Vitro Test ◽  
Large Numbers ◽  
Alternative Approach ◽  
Inactivated Vaccines ◽  
Vitro Test

In the quality control of vaccine batches, the potency testing of inactivated vaccines is one of the areas requiring very large numbers of animals, which usually suffer significant distress as a result of the experimental procedures employed. This article deals with the potency testing of diphtheria and tetanus toxoids, two vaccines which are used extensively throughout the world. The relevance of the potency test prescribed by the European Pharmacopoeia monographs is questioned. The validity of the potency test as a model for the human response, the ability of the test to be standardised, and the relevance of the test in relation to the quality of the product are discussed. It is concluded that the potency test has only limited predictive value for the antitoxin responses to be expected in recipients of these toxoids. An alternative approach for estimating the potency of toxoid batches is discussed, in which a distinction is made between estimation of the immunogenic potency of the first few batches obtained from a seed lot and monitoring the consistency of the quality of subsequent batches. The use of animals is limited to the first few batches. Monitoring the consistency of the quality of subsequent batches is based on in vitro test methods. Factors which hamper the introduction and acceptance of the alternative approach are considered. Finally, proposals are made for replacement, reduction and/or refinement (the Three Rs) in the use of animals in the routine potency testing of toxoids.

Numerical Analysis of Flow Fields and Temperature Fields in a Regenerative Heating Furnace for Steel Pipes

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Yi Han ◽  
Feng Liu ◽  
Xin Ran
Keyword(s):  
Temperature Field ◽  
Flow Field ◽  
Flow Velocity ◽  
Gas Flow ◽  
Flow Fields ◽  
Heating Furnace ◽  
Temperature Fields ◽  
Turbulent Layer ◽  
Steel Pipes ◽  
Pipe Blanks

In the production process of large-diameter seamless steel pipes, the blank heating quality before roll piercing has an important effect on whether subsequently conforming piping is produced. Obtaining accurate pipe blank heating temperature fields is the basis for establishing and optimizing a seamless pipe heating schedule. In this paper, the thermal process in a regenerative heating furnace was studied using fluent software, and the distribution laws of the flow field in the furnace and of the temperature field around the pipe blanks were obtained and verified experimentally. The heating furnace for pipe blanks was analyzed from multiple perspectives, including overall flow field, flow fields at different cross sections, and overall temperature field. It was found that the changeover process of the regenerative heating furnace caused the temperature in the upper part of the furnace to fluctuate. Under the pipe blanks, the gas flow was relatively thin, and the flow velocity was relatively low, facilitating the formation of a viscous turbulent layer and thereby inhibiting heat exchange around the pipe blanks. The mutual interference between the gas flow from burners and the return gas from the furnace tail flue led to different flow velocity directions at different positions, and such interference was relatively evident in the middle part of the furnace. A temperature “layering” phenomenon occurred between the upper and lower parts of the pipe blanks. The study in this paper has some significant usefulness for in-depth exploration of the characteristics of regenerative heating furnaces for steel pipes.

Method of Lines to Solve 2-D Steady Temperature Field of FGM

2007 ◽  
Vol 353-358 ◽  
pp. 2003-2006 ◽  
Author(s):  
Wei Tan ◽  
Chang Qing Sun ◽  
Chun Fang Xue ◽  
Yao Dai
Keyword(s):  
Thermal Conductivity ◽  
Temperature Field ◽  
Transfer Problem ◽  
Method Of Lines ◽  
Main Idea ◽  
Functionally Graded ◽  
Temperature Fields ◽  
Steady Temperature ◽  
Thermal Transfer ◽  
Steady Temperature Field

Method of Lines (MOLs) is introduced to solve 2-Dimension steady temperature field of functionally graded materials (FGMs). The main idea of the method is to semi–discretized the governing equation of thermal transfer problem into a system of ordinary differential equations (ODEs) defined on discrete lines by means of the finite difference method. The temperature field of FGM can be obtained by solving the ODEs with functions of thermal properties. As numerical examples, six kinds of material thermal conductivity functions, i.e. three kinds of polynomial functions, an exponent function, a logarithmic function, and a sine function are selected to simulate spatial thermal conductivity profile in FGMs respectively. The steady-state temperature fields of 2-D thermal transfer problem are analyzed by the MOLs. Numerical results show that different material thermal conductivity function has obvious different effect on the temperature field.

The Study on Foaming Characteristics of Foamed Asphalt in Cold Recycling Technology

2011 ◽  
Vol 243-249 ◽  
pp. 4293-4296
Author(s):  
Jing Li Liu ◽  
Lian Yu Wei ◽  
Guo Qiang Zhang
Keyword(s):  
Quality Control ◽  
Theoretical Basis ◽  
Asphalt Mixture ◽  
Construction Process ◽  
Environment Protection ◽  
Effect Evaluation ◽  
Construction Period ◽  
Foamed Asphalt ◽  
Recycling Technology ◽  
Cold Recycling

Through the foaming mechanism and foaming effect evaluation, this paper analyzes the production procedure, optimum content and strength of foamed asphalt mixture thoroughly. Combined with the construction process quality control and inspection and acceptance criteria, this paper provides data for reference and theoretical basis for application of cold recycled technology of foamed asphalt to pavement project. Its construction without disrupting traffic, thus shorten the construction period and improve efficiency, which also have advantages such as energy conservation, environment protection and economy. Above all, it is beneficial to foamed asphalt′s popularization and application.

scholarly journals Procedure for determining the thermoelastic state of a reinforced concrete bridge beam strengthened with methyl methacrylate

2021 ◽  
Vol 4 (7(112)) ◽  
pp. 26-33
Author(s):  
Vitalii Kovalchuk ◽  
Yuliya Sobolevska ◽  
Artur Onyshchenko ◽  
Olexandr Fedorenko ◽  
Oleksndr Tokin ◽  
...  
Keyword(s):  
Temperature Field ◽  
Reinforced Concrete ◽  
Methyl Methacrylate ◽  
Concrete Beam ◽  
Vertical Direction ◽  
Reinforced Concrete Beam ◽  
Temperature Stresses ◽  
Temperature Changes ◽  
Structural Reinforcement ◽  
Elasticity Module

This paper reports the analysis of methods for determining temperature stresses and deformations in bridge structures under the influence of climatic temperature changes in the environment. A one-dimensional model has been applied to determine the temperature field and thermoelastic state in order to practically estimate the temperature fields and stresses of strengthened beams taking into consideration temperature changes in the environment. The temperature field distribution has been determined in the vertical direction of a reinforced concrete beam depending on the thickness of the structural reinforcement with methyl methacrylate. It was established that there is a change in the temperature gradient in a contact between the reinforced concrete beam and reinforcement. The distribution of temperature stresses in the vertical direction of a strengthened reinforced concrete beam has been defined, taking into consideration the thickness of the reinforcement with methyl methacrylate and the value of its elasticity module. It was established that the thickness of the reinforcement does not have a significant impact on increasing stresses while increasing the elasticity module of the structural reinforcement leads to an increase in temperature stresses. The difference in the derived stress values for a beam with methyl methacrylate reinforcement with a thickness of 10 mm and 20 mm, at elasticity module E=15,000 MPa, is up to 3 % at positive and negative temperatures. It has been found that there is a change in the nature of the distribution of temperature stresses across the height of the beam at the contact surface of the reinforced concrete beam and methyl methacrylate reinforcement. The value of temperature stresses in the beam with methyl methacrylate reinforcement and exposed to the positive and negative ambient temperatures increases by three times. It was established that the value of temperature stresses is affected by a difference in the temperature of the reinforced concrete beam and reinforcement, as well as the physical and mechanical parameters of the investigated structural materials of the beam and the structural reinforcement with methyl methacrylate

scholarly journals A Method for Reconstruction of Boiler Combustion Temperature Field Based on Acoustic Tomography

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yuhui Wu ◽  
Xinzhi Zhou ◽  
Li Zhao ◽  
Chenlong Dong ◽  
Hailin Wang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Optimal Parameter ◽  
Interpolation Method ◽  
Least Square Method ◽  
Reconstruction Algorithm ◽  
Least Square ◽  
Temperature Fields ◽  
Acoustic Tomography ◽  
Measured Temperature

Acoustic tomography (AT), as a noninvasive temperature measurement method, can achieve temperature field measurement in harsh environments. In order to achieve the measurement of the temperature distribution in the furnace and improve the accuracy of AT reconstruction, a temperature field reconstruction algorithm based on the radial basis function (RBF) interpolation method optimized by the evaluation function (EF-RBFI for short) is proposed. Based on a small amount of temperature data obtained by the least square method (LSM), the RBF is used for interpolation. And, the functional relationship between the parameter of RBF and the root-mean-square (RMS) error of the reconstruction results is established in this paper, which serves as the objective function for the effect evaluation, so as to determine the optimal parameter of RBF. The detailed temperature description of the entire measured temperature field is finally established. Through the reconstruction of three different types of temperature fields provided by Dongfang Boiler Works, the results and error analysis show that the EF-RBFI algorithm can describe the temperature distribution information of the measured combustion area globally and is able to reconstruct the temperature field with high precision.

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