scholarly journals Assessing the Marshall Properties of Porous Asphalt Concrete

2021 ◽  
Vol 27 (3) ◽  
pp. 113-129
Author(s):  
Ghaidaa Abdl Wahab Majeed ◽  
Saad Issa Sarsam

Porous asphalt paving is a modern design method that differs from the usual asphalt pavements' traditional designs. The difference is that the design structure of porous pavements allows the free passage of fluids through their layers, which controls or reduces the amount of runoff or water accumulated in the area by allowing the flow of rain and surface runoff.  The cross-structure of this type of paving works as a suitable method for managing rainwater and representing groundwater recharge. The overall benefits of porous asphalt pavements include environmental services and safety features, including controlling the build-up of contaminated metals on the road surface, rainwater management, resistance to slipping accidents, reduced splashing, and spraying pedestrians and drivers. In this study, the porous mixture's volumetric and physical properties were tested, and the use of carbon fibers as a type of mixture improver. The results were compared after performing the following steps: Selecting the best gradient for the porous asphalt mixture by selecting the largest proportion of air voids from three gradations group according to specifications (ASTM 7064), then choosing the optimum asphalt ratio according to the standard specifications, which are the value of drain down % and the Cantabro abrasion loss % value, as well as the ratio of air voids. After obtaining the optimum asphalt ratio, samples of the asphalt mixture were prepared. Carbon fibers were added to it at a rate of (0.3%) by weight of the total mix and a length of (2 cm) and prepared samples without additives. They were tested by a Marshall device to calculate the stability and flow value and show the effects of fibers on porous asphalt concrete properties. An increase in the stability value and a decrease in the flow and reduction in the drain down rate during exposure to high temperature were observed for the samples containing carbon fibers, by 48.8%, 44%, and 72%, respectively

2020 ◽  
Vol 861 ◽  
pp. 414-420
Author(s):  
Ming Xi Liu ◽  
Jian Guang Xie ◽  
Zhan Qi Wang ◽  
Yan Ping Liu

The sound absorption performance of porous asphalt concrete (PAC) is inseparable from the sizes of voids, as different sizes of voids have different absorption effects on noise in different frequency bands. However, the relationship between the two is not clear. In this study, the equivalent diameter of voids was obtained by the proposed image segmentation algorithm based on the square area, then grey entropy method was used to analyze the effect of different equivalent diameter of voids on the sound absorption performance of PAC in the frequency range of traffic noise. The results show that with the increase of air voids, the peak and average sound absorption coefficient of PAC increase, the sound absorption performance of PAC is improved; and the sound absorption performance of PAC is mainly affected by the equivalent diameter of voids of 3-4mm.


2012 ◽  
Vol 174-177 ◽  
pp. 345-353 ◽  
Author(s):  
J. D. Lin ◽  
Ming Chin Yeh ◽  
Po Hsun Sung ◽  
R. H. Shiu

The study applies Computed Tomography technology to probe into the porous asphalt concrete and air voids content, and at the same time, try to qualify accessible voids and closed voids and to use the result to evaluate the performance of porous asphalt concrete. The nominal maximum aggregate of this study is 19.0mm. In order to adjust the image of the gray threshold, the void of PAC specimen was obtained by cut-and-try method with the mix design. After scanning through the PAC specimen, the self-innovated software is used to calculate the Va(%), accessible voids and closed voids. After careful calculation, it showed that the accessible voids are about 20.3%, and the closed voids are about 1.15%. Base on the study, it could analyze the effect of pore clogging in PAC with improved the durability and lifetime.


Author(s):  
Zhanqi Wang ◽  
Jianguang Xie ◽  
Lei Gao ◽  
Yanping Liu ◽  
Lin Tang

2018 ◽  
Vol 1 (4) ◽  
pp. 89-98
Author(s):  
Mohd Fahmi Abdya P. ◽  
Sofyan M. Saleh ◽  
Yusria Darma

Asphalt and Aggregate is the main ingredient of the asphalt concrete layer which determines the quality of asphalt pavement. One of the main cause of the damage and decrease of asphalt pavement strength on the road is the low strength and durability of the asphalt mixture. . But in the other side the utilization of local materials is expected to be used maximally to improve efficiency in terms of financing, especially for island area such as Sabang city of Aceh Province. Importing material from Ace Besar district is need a big cost. In solving this problem therefore it is necessary to maximize the use of local material. this research is done for find out the effect of the use of fine aggregate on the characteristics of the coarse layer of asphalt concrete mixture characteristics (AC-WC)with the addition of Sabang fine aggregate starting from 0%, 25%, 50%, 75% and 100%. The initial step in this research is find the value of optimum asphalt content (KAO).The result of this research shows that the more composition of the Sabang fine aggregate then the decreasing the stability value. The highest stability value is on the asphalt concrete mixture without Sabang fine aggregate substitution with the asphalt content is 5,38% with the amount of 1.658,73 kg and the lowest stability value is on the asphalt concrete mixture with 100% of Sabang fine aggregate substitution with asphalt content is 6,35% in the amount of 979,35 kg. The maximum composition of sabang fine aggregate which pass the requirement specification of Asphalt concrete AC-WC volumetric characteristic is 50% on the level of 5,87% with the stability value is 1.225,81 kg.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 507
Author(s):  
Shi Xu ◽  
Xueyan Liu ◽  
Amir Tabaković ◽  
Erik Schlangen

Microwave heating has been shown to be an effective method of heating asphalt concrete and in turn healing the damage. As such, microwave heating holds great potential in rapid (1–3 min) and effective damage healing, resulting in improvement in the service life, safety, and sustainability of asphalt pavement. This study focused on the microwave healing effect on porous asphalt concrete. Steel wool fibres were incorporated into porous asphalt to improve the microwave heating efficiency, and the optimum microwave heating time was determined. Afterwards, the microwave healing efficiency was evaluated using a semi–circular bending and healing programme. The results show that the microwave healing effect is largely determined by the steel fibre content and the mix design of the porous asphalt concrete.. Besides, the uneven heating effect of microwave contributes to an unstable damage recovery in the asphalt mixture, which makes it less efficient than induction heating. However, microwaves exhibited the ability to penetrate further into the depth of the test specimen and heat beneath the surface, indicating deeper damage recovery prospects.


2020 ◽  
Vol 10 (5) ◽  
pp. 1671 ◽  
Author(s):  
Yanjing Zhao ◽  
Jiwang Jiang ◽  
Yiqing Dai ◽  
Lan Zhou ◽  
Fujian Ni

Porous asphalt concrete (PAC) can obviously improve vehicle driving safety on rainy days and reduce environmental noise. It has been widely used in China. The existence of a large number of interconnected voids in PAC makes a significant difference in heat transfer and temperature distribution from conventional dense-graded asphalt concretes (AC). In this paper, the internal structure images of three dense-graded asphalt mixtures and one PAC were obtained by X-ray CT scanning technology, and the internal meso-structure finite element simulation models of asphalt mixtures were established by using the mapped meshing method. The temperature variations of asphalt mixture specimens during laboratory cooling and heating processes were simulated in this study, and laboratory tests were carried out to verify the simulation accuracy. Due to the simulation results, it was found that the thermal characteristics of the PAC mixture were different from those of the dense-graded asphalt mixture due to the large interconnected air void content in the PAC mixture. The temperature field in the PAC mixture was more sensitive to ambient air temperature under laboratory conditions. Moreover, in PAC specimens, temperature distributed more unevenly than in dense-grade asphalt mixtures. Therefore, it is necessary to consider the internal meso-structure of porous asphalt mixtures while simulating the temperature field in PAC specimens or pavement structures.


2014 ◽  
Vol 1025-1026 ◽  
pp. 749-754
Author(s):  
Chang Hong Zhou ◽  
Shao Hua Liu ◽  
Qiang Yuan

In order to reduce the cost of Porous asphalt concrete and the effective use cheap limestone widely distributed in local, the gradation design works of limestone-typed PAC is presented in this paper. Considering convenience of building and testing for local enterprises, Marshall Design Method, still used in local standards, is adopt. Limestone usually shows low strength and easy break, which obviously affect the performance of mixture. Therefore, Forming temperature and beat numbers of Marshall Test is researched. The results show that: a) Regular aggregate, whose shape is similar to a cube, with low flat ratio and low crushing value is important for improving the performance of limestone-typed PAC. b) Forming temperature and Beat number is suggested taking 155°C and 35 times. c) The standard of limestone-typed PAC should not be as same as basalt-typed. The indices can be suitably lessened according to the actual conditions of aggregates.


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