scholarly journals Investigation of Impact of Aggregate Coating by Bitumen on Change of Micro Texture Values

1970 ◽  
Vol 3 (1) ◽  
pp. 52-61
Author(s):  
Zuzana Florkova ◽  
Jana Pastorkova ◽  
Matus Farbak ◽  
Zuzana Kolkova ◽  
Peter Hrabovsky
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Point Of View ◽  
Skid Resistance ◽  
Analysis Method ◽  
Texture Change ◽  
Bitumen Content ◽  
The Individual ◽  
The Impact

Asphalt pavement micro texture values primarily depend on aggregate properties used in asphalt pavement mixture and by aggregate surfaces is secured the basic contact medium with vehicle tires. It often happens that new asphalt surfaces have not required skid resistance properties and is needed a certain period of time to eliminate film of bitumen binder which is coating the aggregate grain on the surface of pavement by action of vehicles. In most cases, the investigation of the aggregate micro texture impact on the pavement skid resistance properties is carried out under laboratory conditions and generally relates only to measurements on natural aggregate samples (without bitumen). However, due to coating of aggregate by bitumen binder, valleys between the individual peaks of aggregate are filled. Obviously, it can be supposed that the usage of high amount of bitumen content can leads to decreasing of aggregate micro texture values. From this point of view, it can be expected that change in micro texture values depends on the content of binder in the asphalt mixture. Particular aggregate grains were taken from asphalt mixtures samples (AC 8, AC 11 and SMA 11) produced in the laboratory, in order to determine the impact of aggregate coating by bitumen binder on micro texture change. Each usage asphalt mixture was produced with three different bitumen binder contents. Digital image analysis method was used for subsequent evaluation. Changes in the micro texture values depending on the amount of used bitumen binder and also on the calculated theoretical bitumen film thickness are investigated in the conclusion.

scholarly journals Fundamental Approaches to Predict Moisture Damage in Asphalt Mixtures: State-of-the-Art Review

2020 ◽  
Vol 5 (2) ◽  
pp. 20 ◽  
Author(s):  
Hilde Soenen ◽  
Stefan Vansteenkiste ◽  
Patricia Kara De Maeijer
Keyword(s):  
State Of The Art ◽  
Asphalt Pavement ◽  
Flexible Pavements ◽  
Asphalt Mixture ◽  
Moisture Damage ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Moisture Susceptibility ◽  
The Individual

Moisture susceptibility is still one of the primary causes of distress in flexible pavements, reducing the pavements’ durability. A very large number of tests are available to evaluate the susceptibility of a binder aggregate combination. Tests can be conducted on the asphalt mixture, either in a loose or compacted form, or on the individual components of an asphalt pavement. Apart from various mechanisms and models, fundamental concepts have been proposed to calculate the thermodynamic tendency of a binder aggregate combination to adhere and/or debond under wet conditions. The aim of this review is to summarize literature findings and conclusions, regarding these concepts as carried out in the CEDR project FunDBits. The applied test methods, the obtained results, and the validation or predictability of these fundamental approaches are discussed.

scholarly journals Research Progress on Skid Resistance of Basic Oxygen Furnace (BOF) Slag Asphalt Mixtures

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2169
Author(s):  
Song Li ◽  
Rui Xiong ◽  
Jiahui Zhai ◽  
Kaiyin Zhang ◽  
Wenyu Jiang ◽  
...  
Keyword(s):  
Material Properties ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Basic Oxygen Furnace ◽  
Asphalt Mixtures ◽  
Environmental Benefits ◽  
Research Progress ◽  
Skid Resistance ◽  
Basic Oxygen ◽  
Bof Slag

In order to ensure the safety of traffic, asphalt pavement is commonly required to utilize aggregates with excellent anti-abrasion property. This results in the lack of high-quality aggregates. The incorporation of solid waste in the aggregates is regarded as a high potential alternative for solving this problem. Since its material properties, such as rough surface, high Polished Stone Value (PSV) and the excellent adhesion property of asphalt, Basic Oxygen Furnace (BOF) slag can effectively improve the skid resistance of asphalt mixtures. First, the material properties of BOF slag are reviewed in this study. Then, the skid resistance of asphalt mixtures and aggregates are commendably evaluated by the Polished Stone Value test, Wehner/Schulze Tester, Aachen Polishing Machine, British Pendulum Test and Sand Patch test. The physical and mechanical properties of BOF slag play a key role in asphalt mixtures. This review found that the skid resistance mechanism of the BOF slag asphalt mixture is governed by factors such as BOF slag properties, incorporation methods and gradation types. Finally, the economic and environmental benefits of BOF slag asphalt mixtures were discussed. In addition, the function of gas catalysis and the melting of ice and snow can be added to the BOF slag asphalt mixture for a cleaner development in engineering. Furthermore, the existing problems, research directions and corresponding measures in this field are directed towards more durable and functional asphalt pavement construction.

scholarly journals Laboratory comparative assessment of warm and hot mixes Asphalt containing reclaimed Asphalt pavement

2020 ◽  
Vol 8 (2) ◽  
pp. 15-26
Author(s):  
Hasan H Joni ◽  
Aqeel Y M Alkhafaji
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Warm Mix Asphalt ◽  
Asphalt Mixtures ◽  
Reclaimed Asphalt Pavement ◽  
Moisture Resistance ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Marshall Stability ◽  
The Impact

Warm mix Asphalt (WMA) could be mixed and used in paving at low temperatures to minimize the consumption of energy and the emissions of greenhouse gas. Recycled Asphalt pavement (RAP) could save Asphaltic cement and aggregate, which could achieve the better effects of recycling. However, both of the two WMA and RAP technologies have some deficiencies. Warm mix Asphalt and Reclaimed Asphalt pavement (WMA-RAP) technique may solve these issues and deficiencies when they are utilized together. This study investigated the implementations of WMA-RAP and its impacts on the performance of the Asphalt mixture. Under the framework of this study, four percentages of RAP (0%, 20%, 30%, and 40%) were added to the hot mix Asphalt (HMA) and WMA containing 4% Sasobit to study the impact of increasing RAP content on Marshall stability and moisture resistance of Asphalt mixtures. In summary, the Marshall stability of HMA and WMA mixtures is higher than the control mixtures. A small decrease in moisture resistance of both (HMA and WMA) containing RAP comparing to control mixtures Asphalt was observed, as shown by reduced the tensile strength ratios (TSR), but it is still much higher than the minimum of 80%.

Determining Optimum Carbon Nanotubes Content for Asphalt Mixture in Road Pavements

2021 ◽  
Vol 1023 ◽  
pp. 121-126
Author(s):  
Van Bach Le ◽  
Van Phuc Le
Keyword(s):  
Carbon Nanotubes ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Construction Cost ◽  
Asphalt Mixtures ◽  
Static Modulus ◽  
Pavement Construction ◽  
Modified Binder ◽  
Marshall Stability

Although small amount of binder in asphalt concrete mixture may commonly range from 3.5 to 5.5% of total mixture as per many international specifications, it has a significant impact on the total cost of pavement construction. Therefore, this paper investigated the effects of five carbon nanotubes contents of 0.05%, 0.1%, 0.15%, 0.2%, 0.25% by asphalt weight as an additive material for binder on performance characteristics of asphalt mixtures. Performance properties of CNTs modified asphalt mixtures were investigated through the Marshall stability (MS) test, indirect tensile (IDT) test, static modulus (SM) test, wheel tracking (WT) test. The results indicated that asphalt mixtures with CNT modified binder can improve both the rutting performance, IDT strength and marshall stability of tested asphalt mixtures significantly at higher percentages of carbon nanotubes. However, the issue that should be considered is the construction cost of asphalt pavement. Based on the asphalt pavement structural analysis and construction cost, it can be concluded that an optimum CNT content of 0.1% by asphalt weight may be used as additive for asphalt binder in asphalt mixtures.

Rubber Modified Asphalt Mixture Properties and Mechanical Testing

2011 ◽  
Vol 105-107 ◽  
pp. 810-817 ◽  
Author(s):  
Rong Hui Zhang ◽  
Jia Liu ◽  
Jian Chao Huang ◽  
Yi Fu
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Specimen Preparation ◽  
Twin Screw Extrusion ◽  
Modified Asphalt ◽  
Flexural Tensile Strength ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Compound Particle

To solve the high-temperature rutting problem of asphalt pavement, the old rubber of the tire rubber and plastic of general polyethylene waste composite modified asphalt mixture is proposed. The plastic and rubber compound particle was made by the rubber through efficient desulfurization additives, pre-swelling, twin-screw extrusion equipment. The particles mixed with the asphalt mixtures specimen preparation and the dynamic stability experiments, composite beam fatigue experiments, flexural tensile strength and modulus experiments and anti-reflective pavement cracks and other mechanical experiments are performed. The comparative data obtained by the rubber and plastic composited modified asphalt mixtures and SBS asphalt mixtures prove that the rubber and plastic composited modified asphalt mixtures have excellent rutting resistance and fatigue resistance.

scholarly journals How the global economy reflected the year of the pandemic

2021 ◽  
Vol 129 ◽  
pp. 01014
Author(s):  
Vladislav Kaputa ◽  
Frederik Kvočák ◽  
Miroslava Triznová ◽  
Andrej Tomić ◽  
Hana Maťová
Keyword(s):  
Global Economy ◽  
Value Added ◽  
Point Of View ◽  
Environmental Aspects ◽  
Data Comparison ◽  
The Social ◽  
Macroeconomic Indicators ◽  
The Individual ◽  
Reduced Mobility ◽  
The Impact

Research background: The coronavirus pandemic in 2020 had a significant impact on all aspects of life, from the point of view of the individual by forcing social isolation, moving work and study to the home, enormous pressure on the social and health system, but also by forcing closures of services and direct contact with customers. These, as well as other factors, have also had an impact on the performance of economies around the world. Purpose of the article: The paper aims to evaluate the development of the world's major economies in terms of macroeconomic indicators and foreign trade in the pandemic period and previous periods. The social and environmental aspects of the impact of the pandemic on selected economies are also reflected. Methods: Analysis of the main macroeconomic data, comparison and synthesis of findings. Findings & Value added: The interdependence of economies and interconnectedness of markets on transport routes associated with reduced mobility, forced isolation of people and death of economic activity had a significant impact on all the observed indicators, where a significant decline in GDP could be observed in all countries except China. This country was the only one that managed to keep GDP growth in positive numbers. Unemployment development was not equal in the observed economies due to different labour market environment. On the contrary, the environment has benefited in some way.

scholarly journals The impact of forms of unemployment on the social conditions in the Palestinian society from the point of view of the Palestinian youth in the current period between 2015 – 2019: تأثير أشكال البطالة على الأوضاع الاجتماعية في المجتمع الفلسطيني من وجهة نظر الشباب الفلسطيني في الفترة الزمنية الحالية ما بين 2015 – 2019م

2019 ◽  
Vol 3 (12) ◽  
Author(s):  
Abdelmajid Nayif Alawneh
Keyword(s):  
Low Income ◽  
Point Of View ◽  
Social Conditions ◽  
The Social ◽  
The Family ◽  
Palestinian Society ◽  
Individual Family ◽  
The Future ◽  
The Individual ◽  
The Impact

    The research aims to study the impact of unemployment on the social conditions in the Palestinian society from the point of view of the unemployed youth, especially in the current time period (2019), the researcher used the descriptive analytical method, and the research community consists of young people in the governorate of Ramallah. The researcher used the questionnaire tool, and the data were analyzed by the analysis program (SPSS). It was found that the majority of youth are unemployed, they are middle age, single and large families, urban residents, people with specialties and low income. As for the results of the research, there was an increase in the impact of the forms of unemployment on the social conditions of the individual, family and society and their outlook towards the future, came the highest degree on the social conditions of the individual (6. 90%) and then the social conditions of the family (3. 83%), Followed by the societal conditions to reach the value (78%), came the lowest values ​​for the outlook for the future, which amounted to (67%). Some of the features of the impact of unemployment, including the tension, anxiety and frustration of the young group. As for the nature of the relationship between the variables of the study, there was a statistically significant relationship between the combined unemployment and the low income, between the apparent, persuasive and compulsory unemployment, and the individual, family and societal situations and the outlook for them. At the end of the research a number of recommendations were made, most notably the need to balance the types of education and activate the social and cultural role of the family.  

The Analyses and Calculation for Thermal Stresses of SBR Modified Asphalt Pavement

2011 ◽  
Vol 243-249 ◽  
pp. 4112-4118
Author(s):  
Min Jiang Zhang ◽  
Gang Chen ◽  
Li Xia Hou ◽  
Li Ping Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Thermal Stresses ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
The Finite Element Method ◽  
Temperature Stresses ◽  
Modified Asphalt ◽  
Temperature Performance

Based on the viscoelasticity theory and the data of creep test, Burgers model was established, which was used to study the viscoelastic property of SBR asphalt mixtures, and the viscoelastic constitutive relation was obtained. Using the finite element method, the temperature stresses field was calculated under the environmental conditions and the thermal stresses of SBR modified asphalt pavement was given at the last part of this paper. The study indicated that SBR modified asphalt mixtures have the advantage over common asphalt mixture in low-temperature performance.

Superpave Models: Predicting Performance during Design and Construction

1996 ◽  
Vol 1545 (1) ◽  
pp. 105-112
Author(s):  
Gerald A. Huber ◽  
Xishun Zhang ◽  
Robin Fontaine
Keyword(s):  
Prediction Models ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Engineering Properties ◽  
Design System ◽  
Widespread Application ◽  
Premature Failure ◽  
The Impact

The Strategic Highway Research Program (SHRP) spent $50 million researching asphalt binders and asphalt mixtures and provided three main products: an asphalt binder specification, an asphalt mixture specification, and Superpave, an asphalt mixture design system that encompasses both the binder and mixture specification. SHRP researchers have provided tools that promise more robust asphalt mixtures with reduced risk of premature failure. Implementation of the specifications and mix design system will require overcoming several obstacles. Superpave must be demonstrated to be practical and easy to use. The impact of Superpave aggregate requirements on aggregate availability must be determined. The Superpave gyratory compaction procedure has been uniquely defined and then calibrated to traffic volume. The reasonableness of this approach must be tested in widespread application. Perhaps the largest implementation hurdle exists in the performance models. Expensive test equipment is necessary to do the performance-based tests. The performance predictions must be established as reasonable to justify the cost. A highway reconstruction project containing three Superpave Level 1 mix designs is documented including quality control done with the Superpave gyratory compactor. Superpave Level 2 performance-based tests were carried out to predict permanent deformation of the design and the mixture as constructed. The performance-based engineering properties obtained from the tests are evaluated, and the reasonableness of the performance prediction models is discussed.

scholarly journals Interlaminar Bonding Properties on Cement Concrete Deck and Phosphorous Slag Asphalt Pavement

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1427 ◽  
Author(s):  
Guoping Qian ◽  
Shunjun Li ◽  
Huanan Yu ◽  
Xiangbing Gong
Keyword(s):  
Bridge Deck ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Fine Aggregate ◽  
Cement Concrete ◽  
Bonding Properties ◽  
The Impact ◽  
Phosphorous Slag ◽  
Bridge Deck Pavement ◽  
Concrete Deck

The slippage damage caused by weak interlaminar bonding between cement concrete deck and asphalt surface is a serious issue for bridge pavement. In order to evaluate the interlaminar bonding of cement concrete bridge deck and phosphorous slag (PS) asphalt pavement, the shear resistance properties of the bonding layer structure were studied through direct shear tests. The impact of PS as a substitute of asphalt mixture aggregate, interface characteristics, normal pressure, waterproof and cohesive layer types, temperature and shear rate on the interlaminar bonding properties were analyzed. The test results indicated that the interlaminar bonding of bridge deck pavement is improved after asphalt mixture fine aggregate was substituted with PS and PS powder, and the result indicated that the shear strength of grooved and aggregate-exposed interfaces is significantly higher than untreated interface, the PS micro-powder or anti-stripping agent can also improve the adhesion between layers when mixed into SBS asphalt. This study provided important theoretical and practical guidance for improving the shear stability of bridge deck pavement.

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