scholarly journals Modulus Inversion Layer by Layer of Different Asphalt Pavement Structures

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Mingming Cao ◽  
Wanqing Huang ◽  
Yiwen Zou ◽  
Guomin Liu

In order to improve the accuracy of modulus inversion of the pavement structure layer, a layer-by-layer inversion method was proposed to be compared with the traditional inversion method by inverting the modulus of each structural layer of the inverted asphalt pavement and semirigid asphalt pavement. The results show that the influence of cushion modulus on the modulus of inverted subgrade and modulus of cement-stabilized crushed stone is restricted by the cushion modulus and pavement structure characteristics, and the thicker cement-stabilized crushed stone layer is beneficial for improving inverted modulus of subgrade; besides, for the inverted asphalt pavement, the modulus of the graded crushed stone transition layer has a significant influence on the modulus inversion of cement-stabilized crushed stone. The modulus of the graded gravel transition layer inverted by these two methods is underestimated, the modulus of cement-stabilized gravel is overestimated using the traditional inversion method, and the inversion result of the inverted asphalt pavement is more significantly affected by the inversion method than the semirigid base asphalt pavement. Moreover, the modulus of the pavement structural layer is determined by the material and structural characteristics, and its recommended empirical value or the value in the indoor test does not conform to the actual value of the site; by contrast, the inversion modulus obtained using the layer-by-layer inversion method is closer to the actual value, which can be used in the design of similar pavement structures to accumulate data for determining the material modulus or the pavement structure adjustment coefficient in the pavement structure.

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mingming Cao ◽  
Wanqing Huang ◽  
Yiwen Zou ◽  
Zhiyong Wu

Based on the modulus inversion theory and the equivalent principle of deflection basin, by analyzing the deflection basin data of each structure layer measured by the FWD, the obtained equivalent resilient moduli of different structural layers in three different structures (a semirigid type Asphalt pavement and two inverted asphalt pavements) were compared. At the same time, the calculated equivalent resilient modulus of the top surface of the structural layer based on the inversion method was used to modify the existing theory formula. The results show that, with the inversion method and the theoretical calculation method, the calculated equivalent resilient modulus of the top surface of the cushion layer has a small error, but the theoretical calculation method overestimates the equivalent resilient modulus of the top surface of the cement stabilized crushed stone layer and the top surface of the graded crushed stone transition layer, especially for the inverted asphalt pavement; by contrast, the corresponding result of the inversion method is closer to the value in actual engineering. While determining the equivalent resilient modulus of the cushion layer, the influence of the thickness of the cement stabilized crushed stone layer needs to be considered, and the inverted asphalt pavement structure should adopt a thicker asphalt layer to reduce the modulus deviation; at the same time, the more the structural layers and the larger the difference in the interlayer modulus ratio, the larger the deviation of equivalent resilient modulus of the top surface of the base layer; for the inverted asphalt pavement and semirigid asphalt pavement, the correction coefficients of the calculation formula of the equivalent resilient modulus of the top surface of cement stabilized gravel layer are 0.35∼0.55 and 0.65∼0.75, respectively. The inversion method can be used to determine the equivalent resilient modulus of each structural layer of the inverted asphalt pavement and semirigid asphalt pavement, and its results can provide a basis for the design of the structure reconstruction of asphalt pavement.


2013 ◽  
Vol 405-408 ◽  
pp. 1725-1732 ◽  
Author(s):  
Guo Qi Tang ◽  
Dong Wei Cao ◽  
Ke Zhong ◽  
Xiao Qiang Yang

The interlayer bonding of double-layer porous asphalt pavement will show more variations with different construction technologies, such as one-step molding by double-layer (hot on hot) paver, or paving layer by layer (hot on cold) with or without tack coat, and the variations will definitely have influences on pavement structure. Different interlayer technologies are studied in this paper on three levels including simulation experiments on specimen by indoor preparation, calculation of pavement mechanics, and construction of testing road, so that optimal interlayer bonding technology for double-layer porous asphalt pavement is discussed in combination with its effect on permeability.


2021 ◽  
Vol 16 (2) ◽  
pp. 48-65
Author(s):  
Audrius Vaitkus ◽  
Judita Gražulytė ◽  
Andrius Baltrušaitis ◽  
Jurgita Židanavičiūtė ◽  
Donatas Čygas

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.


2020 ◽  
Vol 10 (9) ◽  
pp. 3178
Author(s):  
Hao Li ◽  
Naren Fang ◽  
Xuancang Wang ◽  
Chuanhai Wu ◽  
Yang Fang

The purpose of asphalt pavement structural design is to get a materially-coordinated and structurally-durable product, and a pavement structure with good road performance by combining the structural layer materials reasonably. However, due to lack of a rational evaluation index on the parameter combinations of structural layer materials, the structural layer materials are poor in terms of coordination, have low efficiency, and the actual use period is much lower than the designed working life. Therefore, it is very important to conduct research evaluating the coordination of the structural layer materials. In this study, the sensitivity of mechanical parameters and equivalent envelope area are proposed as new indexes to evaluate the coordination of material design of asphalt pavement structure layers. Software is developed to calculate the equivalent envelope area that can quantitatively evaluate the coordination among different layers and visualize the mechanical transfer behavior of each structural layer. Based on the equivalent envelope area index, this study incorporates two new steps in the design of pavements, namely the structural form comparison and optimization, and proposes a new structural design process. Finally, the rationality and reliability of the equivalent envelope area index are verified by presenting fatigue life calculation and field verification in a test road. The results propose a clear evaluation index of the coordination of material design of each structural layer, which makes the structural design of the asphalt pavement more scientific and reasonable.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Hui Wang ◽  
Zepeng Fan ◽  
Jiupeng Zhang

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.


2019 ◽  
Vol 80 (9) ◽  
pp. 1740-1750 ◽  
Author(s):  
Xiaodong Guo ◽  
Jiupeng Zhang ◽  
Bochao Zhou ◽  
Wolong Liu ◽  
Jianzhong Pei ◽  
...  

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.


2013 ◽  
Vol 723 ◽  
pp. 729-736
Author(s):  
Hong Zhi Li

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Changqing Deng ◽  
Yingjun Jiang ◽  
Zhanchuang Han ◽  
Hongwei Lin ◽  
Jiangtao Fan

Double-layer paving technology, which is a new technology for construction asphalt pavements, has received increasing research attention for several years. However, few studies have focused on the effect of asphalt pavement layer thickness and mixture-type combinations on the fatigue properties of a double-layer pavement. Therefore, the fatigue properties of the double-layer and traditionally paved asphalt pavements were studied in this work. The effects of two paving technologies, three mixture combinations, and two asphalt layer thickness combinations on the fatigue properties of asphalt pavements were studied through bending beam tests, and a fatigue equation of different asphalt pavements was established using the two-parameter Weibull distribution. Subsequently, the fatigue lives of different pavements were compared and analyzed under the same cyclic load. Results indicate that the flexural strength and fatigue life of the double-layer pavement increased by at least 10% and 54%, respectively, compared with those of a traditionally paved pavement structure. The goodness of fit of the equation established using the Weibull distribution exceeded 0.90. For the traditional paving technology, compared with the pavement structure combination of 4-cm AC-13 surface layer/6-cm AC-20 bottom layer, the fatigue life of a 3-cm AC-13 surface layer/7-cm AC-20 bottom layer can be increased by at least 8%, while the fatigue lives of other pavement structures are reduced significantly. The results also indicate that the fatigue life of the double-layer pavement structure with the 3-cm AC-13 surface layer/7-cm AC-20 bottom layer can be increased by at least 114% compared with that of the traditionally paved pavement structure (4-cm AC-13 surface layer/6-cm AC-20 bottom layer). Additionally, the fatigue lives of other pavement structures can be improved. To effectively improve the fatigue life of an asphalt pavement, a double-layer pavement structure with the 3-cm AC-13 surface layer/7-cm AC-20 bottom layer combination is recommended.


2012 ◽  
Vol 204-208 ◽  
pp. 1626-1632
Author(s):  
Hong Wei Peng ◽  
Bi Feng Ou

Based on asphalt pavement design theory and criterions in China, five asphalt structures are put out, including three mix base pavement structures, one typical semi-rigid base pavement structure and one typical flexible base pavement structure. For contract study, different pavement structures were selected with various combinations of modulus and Poisson ratio, but the total thickness is same for comparative analysis. The stress-strain at different depth in asphalt layer is calculated by using BISAR program. The data analysis is carried out for the maximum tensile stress, and the maximum strain of asphalt layer, and the maximum compressive strain on top of sub grade, deflection on asphalt surface. And budget basis price for base is contrasted too. The data analysis results show that the mix base asphalt pavement structures can be designed to get better pavement mechanical performance than typical semi-rigid base and typical flexible base asphalt pavement structures, while the price is higher than that of semi-rigid base. If we consider fatigue life, the cost performance for mix base of upper base with asphalt stabilized macadam is the best. This gives out the important reference for widespread the mix base in future.


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