scholarly journals Reflected cracks buildups surveying and process simulation in double-layer asphalt-concrete systems

2020 ◽  
Vol 7 (3) ◽  
Author(s):  
Aleksey Kamenchukov ◽  
Ilya Ukrainskiy
Keyword(s):  
Double Layer ◽  
Asphalt Concrete ◽  
Lower Layer ◽  
Prototype Model ◽  
Concrete Pavements ◽  
Internal Defects ◽  
Layer System ◽  
The Usa ◽  
Double Layer System ◽  
Asphalt Concrete Pavement

The paper studies the matters of multilayer asphalt-concrete systems cracking resistance, specifically we investigated the occurrence and development causes and peculiarities of the reflected cracks. In this study was examined the highways’ state of repair and the prerequisites for the defects formation on the pavement were determined, as well as the regional road structure operation aspect. The authors studied from every angle the causes of internal and external asphalt concrete pavements defects and deformations. The most popular filling of cracks technologies and restoring the pavement are were discussed in this paper, also the experience of roads repairing in the western part of Russia, Europe, and the USA was investigated. The determination results of the formation and develop-ment defects rate on the surface of the operated roads are presented in this article. Cracks in double-layer samples of finegrained asphalt concrete were simulated in laboratory conditions. A prototype model of 10 cm height and diameter were made by molding and densifying in layers, and a crack was laid in the lower layer of the prototype. Af-ter densifying samples were tested for compression. The physical modeling results analysis allows us to assume the dependence between the presence (or ab-sence) of pavement internal defects and the structural solidity. Mathematical modeling of the operation of a double-layer system was performed in the GenIDE32 software package to confirm the hypothesis. Evaluation of the stress-strain state by the finite element method showed the presence of system weakening characteristics zones around the defect area. There is increasing inter-nal stresses and deformations around the crack in a double-layer system, as well as a decrease in the overall system strength (stability). In the end, conclusions about the influence of asphalt-concrete pavement internal defects on the reflected cracks formation pro-cess were drawn.

scholarly journals MODELING OF REFLECTED CRACKS IN ASPHALT CONCRETE PAVEMENT OF HIGHWAYS

2021 ◽  
pp. 1-9
Author(s):  
Aleksey Kamenchukov ◽  
Ilya Ukrainskiy ◽  
Nikina Bushuev ◽  
Nikolay Kim
Keyword(s):  
Asphalt Concrete ◽  
Lower Layer ◽  
Internal Stresses ◽  
Concrete Pavements ◽  
Internal Defects ◽  
Layer System ◽  
Multilayer Systems ◽  
The Road ◽  
Fine Grained ◽  
The Usa

The paper considers the issues of crack resistance of multilayer systems made of asphalt concrete, namely: the causes and features of the occurrence and development of "reflected" cracks are investigated. A study of the operational state of highways was carried out and the prerequisites for the formation of defects on the pavement were determined, including the regional features of the work of the road structure. The authors comprehensively studied the causes of internal and external defects and deformations of asphalt concrete pavements. The most popular technologies for sealing cracks and restoring the pavement are considered, the experience of repairing roads in the western part of Russia, Europe and the USA is also investigated. The results of determining the rate of formation and development of defects in the surface of the exploited roads are presented. In laboratory conditions, work was carried out to simulate cracks in two-layer samples of fine-grained asphalt concrete. Test specimens with a height and diameter of 10 cm were made by molding and compacted in layers, a crack was laid in the lower layer of the specimen. After gaining strength, the samples were tested for compression. Analysis of the results of physical modeling made it possible to put forward an assumption about the existence of a relationship between the presence (absence) of internal defects in the coating and the strength of the structure. To confirm the hypothesis, mathematical modeling of the operation of a two-layer system in the GenIDE32 software package was performed. Evaluation of the stress-strain state by the finite element method showed the presence of characteristic zones of system weakening around the defect area. In a two-layer system, there is an increase in internal stresses and strains around the crack, as well as a decrease in the overall strength (stability) of the system. In conclusion, the influence of internal defects of asphalt concrete coatings on the process of formation of "reflected" cracks were identified.

scholarly journals Characteristics of Oceanic Warm Cloud Layers within Multilevel Cloud Systems Derived by Satellite Measurements

Atmosphere ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 465 ◽  
Author(s):  
Yuhao Ding ◽  
Qi Liu ◽  
Ping Lao
Keyword(s):  
Double Layer ◽  
Lower Layer ◽  
Single Layer ◽  
Distribution Patterns ◽  
Radar Data ◽  
Multilayered Structures ◽  
Layer System ◽  
Cloud Systems ◽  
Warm Cloud ◽  
Double Layer System

Low-level warm clouds are a major component in multilayered cloud systems and they are generally hidden from the top-down view of satellites with passive measurements. This study conducts an investigation on oceanic warm clouds embedded in multilayered structures by using spaceborne radar data with fine vertical resolution. The occurrences of warm cloud overlapping and the geometric features of several kinds of warm cloud layers are examined. It is found that there are three main types of cloud systems that involve warm cloud layers, including warm single layer clouds, cold-warm double layer clouds, and warm-warm double layer clouds. The two types of double layer clouds account for 23% and in the double layer occurrences warm-warm double layer subsets contribute about 13%. The global distribution patterns of these three types differ from each other. Single-layer warm clouds and the lower warm clouds in the cold-warm double layer system they have nearly identical geometric parameters, while the upper and lower layer warm clouds in the warm-warm double layer system are distinct from the previous two forms of warm cloud layers. In contrast to the independence of the two cloud layers in cold-warm double layer system, the two kinds of warm cloud layers in the warm-warm double layer system may be coupled. The distance between the two layers in the warm-warm double layer system is weakly dependent on cloud thickness. Given the upper and lower cloud layer with moderate thickness of around 1 km, the cloudless gap reaches its maximum when exceeding 600 m. The cloudless gap decreases in thickness as the two cloud layers become even thinner or thicker.

Oceanic warm cloud layers within multilevel cloud systems observed by satellite measurements

2020 ◽  
Author(s):  
Qi Liu ◽  
Yuhao Ding ◽  
Ping Lao
Keyword(s):  
Double Layer ◽  
Radiative Forcing ◽  
Lower Layer ◽  
Numerical Models ◽  
Three Dimensional ◽  
Single Layer ◽  
Layer System ◽  
Cloud Systems ◽  
Warm Cloud ◽  
Double Layer System

<p>Low-level warm clouds are a major component in multilayered cloud systems and are generally hidden from the top-down view of satellites with passive measurements. By using spaceborne radar data with fine vertical resolution, this study conducts an investigation on oceanic warm clouds embedded in multilayered structures. The occurrences of warm cloud overlapping and the geometric features of several kinds of warm cloud layers are examined. It is found that there are three main types of cloud systems that involve warm cloud layers, including warm single layer clouds, cold-warm double layer clouds and warm-warm double layer clouds. The two types of double layer clouds account for 23% and in the double layer occurrences warm-warm double layer subsets contribute about 13%. The global distribution patterns of these three types differ from each other. Single-layer warm clouds and the lower warm clouds in the cold-warm double layer system have nearly identical geometric parameters, while the upper and lower layer warm clouds in the warm-warm double layer system are distinct from the previous two forms of warm cloud layers. In contrast to the independence of the two cloud layers in cold-warm double layer system, the two kinds of warm cloud layers in the warm-warm double layer system may be coupled. The distance between the two layers in the warm-warm double layer system is weakly dependent on cloud thickness. Given the upper and lower cloud layer with moderate thickness around 1 km, the cloudless gap reaches its maximum exceeding 600 m. As the two cloud layers become even thinner or thicker, the cloudless gap decreases in thickness. It is believed that such knowledge on cloud overlapping is critical for fully understanding the distribution of warm clouds in three-dimensional space. The results derived in this study could help validating cloud results of numerical models, which are indeed three-dimensional in nature. They could also be used to improve the estimation of cloud radiative forcing, since it is affected by cloud occurrences and especially their vertical structures. It should be pointed out that solid explanations for the above cloud features cannot be presented by only using these satellite data themselves. </p>

scholarly journals Six-Year Evaluation of Thermal-Sprayed Coating of Zn/Al in Tropical Marine Environments

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Orlando Salas ◽  
Oladis Troconis de Rincón ◽  
Daniela Rojas ◽  
Adriana Tosaya ◽  
Nathalie Romero ◽  
...  
Keyword(s):  
Double Layer ◽  
Visual Inspection ◽  
Erosion Resistance ◽  
Microscopic Analysis ◽  
Marine Environments ◽  
Initial Weight ◽  
Layer System ◽  
Double Layer System ◽  
Sprayed Coating ◽  
Very High

The main objective of this research was to evaluate the performance of thermal-sprayed coating of Zn/Al (double layer) after six years of exposure, with and without the use of sealant (wash primer) in tropical marine environments of very high aggressiveness: La Voz Station (located at the Peninsula de Paraguaná/Falcón State) and Lake Maracaibo Crossing Station (located at Zulia State), in Venezuela. To that effect, carbon steel coupons (100 mm × 150 mm × 2 mm) were sprayed by flame process. The coupons were characterized by means of initial weight, thickness, metallographic, adherence, and roughness, being evaluated monthly by visual inspection during six years. After removal, the coupons were evaluated by microscopic analysis to determine the morphology of attack, microstructure, penetration of contaminants, composition, and morphology of corrosion products. The results showed that after six years, the double-layer system represents an excellent choice for corrosion protection of steel by combining the galvanic protection of zinc with the erosion resistance of aluminum. However, due to the erosion-corrosion effect, a sealant such as wash primer can be used in order to extend its service life.

Modeling Analysis of Crack Repairing Structures for Asphalt Concrete Pavement

2013 ◽  
Vol 639-640 ◽  
pp. 377-381 ◽  
Author(s):  
Yi Chi ◽  
Jian Yin
Keyword(s):  
Asphalt Concrete ◽  
Composite Structure ◽  
Concrete Pavement ◽  
Concrete Pavements ◽  
Filling Materials ◽  
Modeling Analysis ◽  
Strain Stress ◽  
The Stability ◽  
Asphalt Concrete Pavement ◽  
External Loads

Crack is one of the major distresses in asphalt concrete pavements, which could significantly reduce the safety and amenity of driving, even the performance of the whole pavement structure. By means of diverse crack repairing manners, the durability and whole service life of the pavement can be improved and extended. After repairing, a composite structure of the repairing system is formed which consists of new crack filling materials and original asphalt concrete matrixes. In order to resist the external loads on the pavement, the composite structure mush work as an integrated structure and maintain sufficient adhesive strength. Therefore, the deformation compatibility of the composite structure is the vital performance for the stability and durability of the entire repairing system. In this study, a modeling analysis for the composite structure under various service conditions was carried out utilizing MIDAS software. The vertical and transverse deformation, transverse and longitudinal normal stress were analyzed by simulating the composite structure under several serving conditions. Based on the results，it was found that the strain, stress and related properties of the repair material and asphalt concrete matrixes could meet the requirements for an asphalt concrete pavement, and the compatibility of the composite structure was also satisfactory.

scholarly journals THERMAL CONDITIONS OF ROAD PAVEMENTS AND THEIR INFLUENCE ON MOTOR TRAFFIC

Transport ◽  
2003 ◽  
Vol 18 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Alfredas Laurinavičius ◽  
Donatas Ďygas
Keyword(s):  
Asphalt Concrete ◽  
Thermal Conditions ◽  
Climatic Conditions ◽  
Concrete Pavement ◽  
Concrete Pavements ◽  
Road Asphalt ◽  
Concrete Mixtures ◽  
Research Findings ◽  
The Republic ◽  
Asphalt Concrete Pavement

The article presents the analysis of climatic conditions in the Republic of Lithuania and describes their influence on road asphalt concrete pavement. Dependence of the main properties of asphalt concrete mixtures on tempera~re is described with the help of carried out experiments. Research findings show that the probability of plastic defomations (rutting and corrugation) in asphalt concrete pavement is higher when the pavement temperature IS 20-40 C. Ptactical application of the presented conclusions and recommendations will enable to reduce the occurrence of undesirable deformations in asphalt concrete pavements and to improve traffic conditions on the roads.

Simulation of a humidity-sensitive double-layer system

1994 ◽  
Vol 18 (1-3) ◽  
pp. 303-307 ◽  
Author(s):  
Gerald Gerlach ◽  
Karsten Sager ◽  
Andreas Schroth
Keyword(s):  
Double Layer ◽  
Layer System ◽  
Double Layer System
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