Cracks Resisting Mechanism Analysis of Large Stone Mixture Base Based on Mechanics Calculations

2013 ◽  
Vol 723 ◽  
pp. 729-736
Author(s):  
Hong Zhi Li
Keyword(s):  
Temperature Stress ◽  
Coupling Effect ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Element Model ◽  
Stress And Strain ◽  
Mechanism Analysis ◽  
Large Stone ◽  
Pavement Structure ◽  
Pavement Structures

In order to study the cracks resisting mechanism of large stone asphalt mixture base, a multi-layer elastic theory program was used to calculate the loading stress in different pavement structures. Then a Finite Element model was established based on a twinkling heat conduct hypothesis to calculate temperature stress and strain of pavement structure when temperature dropped. Finally, the stress and strain of all the structural layers was calculated considering the coupling effect of loading and temperature. It is found that temperature stress which is caused by temperate quick dropped is far more lager than loading stress cause by standard loading, while considering the co-effect of vehicle loading and temperature quickly dropped. Thus it is revealed that cracking in pavement is mainly caused by temperature quickly dropped. By contrast, it is found that pavement stress and strain caused by loading and temperature of the structure with asphalt macadam mixture (ATB30) base are less than that of the conventional semi-rigid pavement. Finally, an asphalt macadam mixture base applied in asphalt pavement structure is believed to be an efficient way in reducing asphalt pavement cracking.

Stress and Strain Analysis of Asphalt Pavement Impacted by Temperature and Load

2014 ◽  
Vol 638-640 ◽  
pp. 1177-1184
Author(s):  
Jian Li
Keyword(s):  
Surface Deformation ◽  
Coupling Effect ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Road Surface ◽  
Effect Of Temperature ◽  
Load Factor ◽  
Stress And Strain ◽  
Single Temperature ◽  
Pavement Structure

Temperature and load are the major factors of road surface deformation. This paper studies how the temperature causes the road surface deformation and what the deformation trend is. A simplified model of the pavement structure and double round load loading mode were adopted respectively to analyze the stress and strain changes of road surface result of the load and the coupling effect of temperature and load. The major conclusions drew on this study are: stiffness modulus of asphalt mixture attenuates rapidly as the temperature increases, and thereby results in a significant shear deformation of asphalt pavement. At the same temperature, compressive stress decreases with the increasing of load and the deepening of the pavement structure. The influence of coupling effect of temperature and load is more significant than a single temperature or load factor. Under different coupling effect of temperature and load circumstances, the pavement structure influenced mostly by the shear stress is located 3-9cm underneath the surface.

scholarly journals Long-Term Performance of Pavement Structures with Cold In-Place Recycled Base Course

2021 ◽  
Vol 16 (2) ◽  
pp. 48-65
Author(s):  
Audrius Vaitkus ◽  
Judita Gražulytė ◽  
Andrius Baltrušaitis ◽  
Jurgita Židanavičiūtė ◽  
Donatas Čygas
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Pavements ◽  
Recycled Asphalt ◽  
Binding Agents ◽  
Pavement Structure ◽  
Pavement Structures ◽  
Base Course ◽  
Surface Distress ◽  
Foamed Bitumen

Properly designed and maintained asphalt pavements operate for ten to twenty-five years and have to be rehabilitated after that period. Cold in-place recycling has priority over all other rehabilitation methods since it is done without preheating and transportation of reclaimed asphalt pavement. Multiple researches on the performance of cold recycled mixtures have been done; however, it is unclear how the entire pavement structure (cold recycled asphalt pavement overlaid with asphalt mixture) performs depending on binding agents. The main objective of this research was to evaluate the performance of cold in-place recycled asphalt pavements considering binding agents (foamed bitumen in combination with cement or only cement) and figure out which binder leads to the best pavement performance. Three road sections rehabilitated in 2000, 2003, and 2005 were analysed. The performance of the entire pavement structure was evaluated in terms of the International Roughness Index, rut depth, and pavement surface distress in 2013 and 2017.

scholarly journals Development of a Full-Depth Wheel Tracking Test for Asphalt Pavement Structure: Methods and Performance Evaluation

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Hui Wang ◽  
Zepeng Fan ◽  
Jiupeng Zhang
Keyword(s):  
Performance Evaluation ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Single Layer ◽  
Test Method ◽  
Shanxi Province ◽  
Wheel Tracking Test ◽  
Pavement Structure ◽  
Pavement Structures ◽  
Wheel Tracking

The rutting performance of asphalt pavement structure relies on the high temperature properties of asphalt mixture as well as the pavement structure and thickness. In order to investigate the influence of the structure and thickness, a full-depth wheel tracking test is developed in this research by improving the conventional wheel tracking test apparatus. The newly proposed test method is capable of varying its load speed and load size, controlling its specimen temperature gradient, and simulating the support conditions of actual asphalt pavement. The full-depth wheel tracking test based rutting performance evaluation of different asphalt pavement structures indicates that it is not reasonable to explain the rutting performance of asphalt pavement structure from the point of view of single-layer asphalt mixture rutting performance. The developed full-depth wheel tracking test can be used to distinguish rutting performance of different asphalt pavement structures, and two of five typical asphalt pavement structures commonly used in Shanxi Province were suggested for use in practical engineering.

Key Technique on the Process Control for Construction of Hohhot Circle Expressway Asphalt Pavements

2012 ◽  
Vol 256-259 ◽  
pp. 1748-1753
Author(s):  
Bin Zhao ◽  
Pei Wen Hao
Keyword(s):  
Inner Mongolia ◽  
Raw Materials ◽  
Asphalt Pavement ◽  
Load Capacity ◽  
Asphalt Mixture ◽  
Natural Increase ◽  
Rigid Base ◽  
Construction Technology ◽  
Pavement Structure ◽  
Major Section

As vehicle flow on arterial highway in Inner Mongolia sharply increased, the originally designed natural increase rate of 8% per year has been exceeded on the vehicle flow in some sections. According to statistics, monthly average vehicle flow on major section of G6 expressway has reached a standard flow of 67478 vehicles per day and night, of which in 70-80% are large ones for coal transportation. Therefore, pavement load and road capacity have exceed the designed expressway load capacity. At present, semi-rigid base asphalt pavement structure is still widely used for high-grade highway pavement in Inner Mongolia. With years of construction for such pavement structure, a great deal of valuable experience has been gained on construction technology. However, there are still a few deficiencies in the quality of raw materials, gradation control of asphalt mixture and adjustment of equipment, etc. Hohhot circle expressway connects with the G6 and G7 expressways, suffering from problems such as large vehicle flow and load overweight. This paper introduced a key technique that should be properly controlled during construction of such pavement structure, emphasized technique control and management of the following aspects, i.e. ballast sizes and gradation control, asphalt concrete mixture, adjustment of pavers, validation of mixing proportion in production and reasonable arrangement of process, and summarized corresponding technical measures taken during construction of asphalt pavement in this project.

scholarly journals Unified Strength Model of Asphalt Mixture under Various Loading Modes

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 889 ◽  
Author(s):  
Chengdong Xia ◽  
Songtao Lv ◽  
Lingyun You ◽  
Dong Chen ◽  
Yipeng Li ◽  
...  
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Structure Design ◽  
Strength Model ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Direct Tension ◽  
Indirect Tension ◽  
Pavement Structure ◽  
Loading Modes

Although the rutting resistance, fatigue cracking, and the resistance to water and frost are important for the asphalt pavement, the strength of asphalt mixture is also an important factor for the asphalt mixture design. The strength of asphalt mixture is directly associated with the overall performance of asphalt mixture. As a top layer material of asphalt pavement, the strength of asphalt mixture plays an indispensable role in the top structural bearing layer. In the present design system, the strength of asphalt pavement is usually achieved via the laboratory tests. The stress states are usually different for the different laboratory approaches. Even at the same stress level, the laboratory strengths of asphalt mixture obtained are significantly different, which leads to misunderstanding of the asphalt mixtures used in asphalt pavement structure design. The arbitrariness of strength determinations affects the effectiveness of the asphalt pavement structure design in civil engineering. Therefore, in order to overcome the design deviation caused by the randomness of the laboratory strength of asphalt mixtures, in this study, the direct tension, indirect tension, and unconfined compression tests were implemented on the specimens under different loading rates. The strength model of asphalt mixture under different loading modes was established. The relationship between the strength ratio and loading rate of direct tension, indirect tension, and unconfined compression tests was adopted separately. Then, one unified strength model of asphalt mixture with different loading modes was established. The preliminary results show that the proposed unified strength model could be applied to improve the accurate degree of laboratory strength. The effectiveness of laboratory-based asphalt pavement structure design can therefore be promoted.

Mechanism Analysis of Rutting at Urban Intersections Based on Numerical Simulation of Moving Loads

2010 ◽  
Vol 152-153 ◽  
pp. 1192-1198 ◽  
Author(s):  
Ze Jiao Dong ◽  
Zong Jie Sun ◽  
Xiang Bing Gong ◽  
Hao Liu
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Asphalt Pavement ◽  
Moving Load ◽  
Maximum Shear Stress ◽  
Uniform Motion ◽  
Dynamic Mode ◽  
Mechanism Analysis ◽  
Horizontal Shear ◽  
Pavement Structure

Frequent starting and braking of vehicles causes rutting of asphalt pavement at urban intersection. As a result, dynamic response of pavement subjected to these kinds of vehicle loadings can be used to analyze rutting mechanism. At first, vehicle loading at urban intersection was described by a vertical and horizontal combined moving pressure with variable speeds. Then, three-dimensional finite element model in transient dynamic mode is developed based on the practical pavement structure. And the moving load, boundary conditions and material parameters were briefly introduced. Finally, through the comparison of time histories and spatial distribution among accelerating, decelerating and uniform motion, mechanism of rutting of asphalt pavement at urban intersections was illustrated according to the finite element simulation. It shows that frequent starting and braking of vehicle at urban intersections, obviously change the stress distribution within pavement structure compared with uniform motion case. The distribution and amplitude of maximum shear stress and horizontal shear stress was observed during the passage of the loading, which will result in shear flow deformation. Pavement structure subjected to moving load exhibits an alternative characteristic which will accelerate the rutting damage of pavement.

Contrastive Studies of Asphalt Pavement on Suction Exothermic Properties and Cooling Measures

2011 ◽  
Vol 97-98 ◽  
pp. 290-296
Author(s):  
Wei Guang Li ◽  
Zhi Dong Han ◽  
Zhen Bei Lv ◽  
Yan Hong Duan
Keyword(s):  
Heat Storage ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Heat Island ◽  
Regular Pattern ◽  
Island Effect ◽  
Different Types ◽  
Urban Heat ◽  
Pavement Structure ◽  
Quantity Of Heat

It is important to reduce asphalt mixture strong absorption characteristics to improve anti-rutting ability and reduce the urban heat island effect. This paper firstly studies the suction and exothermic regular pattern of existing three types, five kinds of asphalt pavement structure. It turns out that there are differences in suction and exothermic characteristics of different types of pavement structure. Suspension close-grained type structure has higher adiabatic heating; gap-type skeleton has faster speed of suction and exothermic; and dense skeleton has more total quantity of heat storage. Accordingly, test and analysis of cooling effect of Gap-type skeleton asphalt pavement has conducted by adopting smear reflective materials to reduce reflectance and surface adding insulation materials, The results show that reducing reflectivity is the best way which can reduce by 5 centigrade around. In addition , improving effectiveness has also been studied by adding light-colored stone partly replacing mineral aggregate, and substituting busing mullite for aggregate below2.36 mm is the best cooling way ,which can reduce by 3.3 centigrade.

Coupled Numerical Analysis of the Anti-Crack Mechanism for Open-Graded Large Stone Asphalt Mixes

2009 ◽  
Vol 79-82 ◽  
pp. 1149-1152
Author(s):  
Hong Bing Guo ◽  
Shuan Fa Chen
Keyword(s):  
Finite Element ◽  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
Rigid Base ◽  
Reflective Cracking ◽  
Large Stone ◽  
Concrete Base ◽  
Test Road ◽  
Cracking Performance ◽  
Pavement Structure

The reflective cracking in asphalt surface is a technical problem that exists in the semi-rigid base asphalt pavement structure and the rigid base asphalt pavement structure, how to control its emergence and development is still a major problem for road engineering. At present, researches on the anti-cracking performance for Open-graded Large Stone asphalt Mix (OLSM) in China almost remain in the test road observations, very few study the mechanism of its anti-cracking from the mechanical point. Aiming at this problem, a method of using OLSM as the cracking relief layer is proposed, large mineral aggregate, low asphalt content and a great deal of void in OLSM can dissipate or absorb stress and strain around the crack. The 3-D finite element method is used to analyze the crack-alleviating layer of ordinary asphalt concrete and OLSM, and the large-scale commercial finite element software of ABAQUS is used to do numerical simulation analysis for the lean concrete base asphalt pavement structure with OLSM, the analysis result indicates that temperature-load coupling stress of OLSM are less than that of ordinary asphalt concrete. Depending on the test road on an expressway, research on the anti-crack mechanism of OLSM has been conducted. The investigation of the test road and the result of the theoretical calculation indicate that OLSM can prevent lean concrete base asphalt pavement from the reflective cracking effectively, OLSM has good anti-cracking performance, it is an effective material to alleviate the reflective cracking. As the crack-alleviating layer, OLSM can significantly enhance the anti-cracking ability of the semi-rigid base asphalt pavement structure and the rigid base asphalt pavement structure.

Sponge roads: the permeable asphalt pavement structures based on rainfall characteristics in central plains urban agglomeration of China

2019 ◽  
Vol 80 (9) ◽  
pp. 1740-1750 ◽  
Author(s):  
Xiaodong Guo ◽  
Jiupeng Zhang ◽  
Bochao Zhou ◽  
Wolong Liu ◽  
Jianzhong Pei ◽  
...  
Keyword(s):  
Surface Layer ◽  
Bearing Capacity ◽  
Asphalt Pavement ◽  
Structure Design ◽  
Urban Agglomeration ◽  
Central Plains ◽  
Rainfall Characteristics ◽  
Combination Scheme ◽  
Pavement Structure ◽  
Pavement Structures

Abstract Permeable asphalt pavement should be selected according to the rainfall characteristics of the project site, so as to improve the permeable performance and ensure the bearing capacity of the pavement structure. Therefore, taking a city in the central plains urban agglomeration of China as an example, the characteristics of the rainstorm intensity distribution and cumulative rainfall are analyzed, and a combination scheme of drainage surface layer asphalt pavement suitable for rainfall characteristics in this area is proposed. Then, the pavement structure design is systematically carried out based on the permeable capacity and bearing capacity. The results show that under the rainfall conditions in this area, there is no surface runoff on the permeable asphalt pavement with 120 mm drainage surface layer, which is suitable for the medium traffic grade of urban roads with cumulative equivalent axle loads of 10 million to 12 million times.

Study on Low Temperature Performance of SBS Modified Asphalt and its Mixture

2014 ◽  
Vol 587-589 ◽  
pp. 1332-1336
Author(s):  
Jun Qing Chen ◽  
Ai Jun Li ◽  
Mei Qian Jin ◽  
Min Nan Zheng ◽  
Wan Yi Yang
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Temperature Stress ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Modified Asphalt ◽  
Temperature Performance ◽  
Low Temperature Cracking ◽  
Low Temperature Performance ◽  
Sbs Modified Asphalt

Prone to low temperature cracking of asphalt pavement problems in cold areas, testing BBR on 70# base asphalt and 4 kinds of different dosage of SBS modified asphalt, testing TSRST on their mixture to appraisal the low temperature performance of SBS modified asphalt mixture. Results show that compared with the temperature stress of internal cracks of base asphalt and SBS modified asphalt mixture not rise significantly. But the stress of SBS asphalt mixture growing slow and the temperature of cracking reduce obviously; it means the low temperature performance improved. This shows that SBS improves the toughness and reduced the modulus of asphalt mixture in low temperature, rather than increasing the tensile strength of mixture specimens.

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