scholarly journals The Effectiveness of Liquid PUD-TiO2 Photocatalyst on Asphalt Pavement

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7805
Author(s):  
Dae-Seong Jang ◽  
Sang-Hoon Kim ◽  
Young Kim ◽  
Jae-Jun Lee ◽  
Deok-Soon An

Harmful nitrogen oxides (NOX) are produced by vehicles, factories, mines, and power plants. In fact, over one million tons of NOX are emitted into the atmosphere every year, making it the most prevalent air pollutant. Approximately 45% of the emitted NOX in Korea is associated with the transportation sector. In this paper, the application of a new TiO2 photocatalyst on the asphalt roads to remove combustion-produced NOX was studied. In an effort to overcome the known constructability, adhesion, cost, and dispersion problems associated with TiO2 photocatalysts, the liquid polyurethane (PUD) was added with TiO2 to form a mixture later known as liquid PUD-TiO2. Laboratory and field tests were conducted to determine the optimum amount of photocatalyst to be used and the performance of asphalt pavement coated with PUD-TiO2 in terms of indirect tensile strength, water susceptibility, and rutting resistance. Additionally, the performance of PUD-TiO2 under different humidity, wind speed, and temperature conditions was also evaluated. The results showed that the application of PUD-TiO2 photocatalyst on the asphalt pavements road reduces the NOX available on the surface of the road. The PUD-TiO2 also was found to have no effects on the performance of asphalt pavement. Meanwhile, under different weather conditions, the reaction between the photocatalyst and NOX is mainly affected by the humidity.

DYNA ◽  
2016 ◽  
Vol 83 (196) ◽  
pp. 194-203
Author(s):  
Myriam Rocío Pallares Muñoz ◽  
Julián Andrés Pulecio-Díaz

<p>The effect of a dual tire pressure on the design parameters of thick asphalt pavements using finite element freeware EverStressFE©1.0 is evaluated. This is trying to represent more adjusted the footprint shape and intensity of stress generated by the tires of vehicles. To validate the elastic multilayer EverStress©5.0 software was used. The results of the deformations can be concluded that the asphalt pavement designs made with analytical methods may be slightly oversized and consequently increase the cost of construction of pavements. This study marks a route to analyze the sensitivity of various factors that may affect the design of asphalt pavements. Future research is expected to integrate dynamic conditions by introducing results of field tests to full scale.</p>


2021 ◽  
Vol 4 (6) ◽  
Author(s):  
Zecheng Ni ◽  
Shijing Chen ◽  
Yihuan Li ◽  
Hongxi Peng ◽  
Jiawen Liang ◽  
...  

The early asphalt pavement in our country severely reduced the road performance due to various external factors during the use process. According to incomplete statistics, there are more asphalt pavements that need to be renovated and repaired every year in China, and the amount of construction waste such as asphalt concrete and other construction waste reaches 1,000. About ten thousand tons. If such a huge amount of construction waste is not used, it will inevitably cause great pollution to the environment. If it can be reused, not only will it be environmentally friendly and energy-saving, it will also save more than one billion yuan in costs. In view of the above problems, this article conducts related Research and Analysis on the Principle in Plant Cold Recycling for Foamed Bitumen and Mixture Performance to provide reference for future projects.


Author(s):  
Ruxin Jing ◽  
Aikaterini Varveri ◽  
Xueyan Liu ◽  
Athanasios Scarpas ◽  
Sandra Erkens

The degradation of bituminous materials as a result of ageing has a significant effect on asphalt pavement performance. In this study, one porous asphalt (PA) section and one stone mastic asphalt (SMA) asphalt pavement section were designed and constructed in 2014 and exposed to the actual environmental condition. To study the change in the pavement’s mechanical properties, asphalt cores were collected from both test sections annually. The change in stiffness modulus was determined via cyclic indirect tensile tests. To investigate the ageing behavior across the pavement depth, the bitumen was extracted and recovered from 13 mm slices along the depths of the cores. The chemical composition and rheological properties of the field-recovered bitumen, and that of original bitumen aged in standard short- and long-term ageing protocols, were investigated by means of the Fourier Transform Infrared (FTIR) spectrometer and Dynamic Shear Rheometer. The results show that the effect of mineral aggregate packing, and therefore of air-void distribution and connectivity, on the ageing sensitivity of the pavements with time was significant, as the changes in the stiffness of the PA mixture were greater than that of SMA mixture. In addition, the results of field-recovered bitumen show that there is an ageing gradient inside the porous asphalt layer, however, the ageing of SMA mainly happens on the surface of the layer. Finally, the field-recovered and laboratory-aged bitumen results demonstrate a weak relation between field and standard laboratory ageing protocols.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5523
Author(s):  
Jingsheng Pan ◽  
Hua Zhao ◽  
Yong Wang ◽  
Gang Liu

The influence of sand accumulation on the skid resistance of asphalt pavement was studied. Many scholars have researched the anti-skid performance of conventional asphalt pavements. However, there is a lack of research on the anti-skid performance of desert roads under the condition of sand accumulation. In this study, AC-13 and AC-16 asphalt mixtures were used. The British Pendulum Number (BPN) under different sand accumulations was measured with a pendulum friction coefficient meter, and the Ames engineering texture scanner was used to obtain different sand accumulations. The texture index of asphalt mixture was used to study the macro and micro texture of asphalt pavement under different amounts of sand accumulation, and the degree of influence of different particle sizes on BPN was obtained through gray correlation analysis. The test results show that the presence of aeolian sand has a significant impact on the macro and micro texture of the asphalt pavement and will cause the anti-skid performance to decrease. Moreover, there is an apparent positive linear correlation between the road surface texture index and BPN. The research results may provide reference and reference for the design and maintenance of desert highways.


2014 ◽  
Vol 617 ◽  
pp. 29-33 ◽  
Author(s):  
Jozef Melcer

Asphalt pavements are the transport structures subjected to dynamic effect of moving vehicles. Many effects influence the real values of vehicle tire forces. Road unevenness represents the most important factor influencing the magnitudes of tire forces. Such data can be obtained by numerical or experimental way. The paper deals with the numerical simulation of moving load effect on asphalt pavements and with numerical simulation of tire forces in relation to the road unevenness.


2012 ◽  
Vol 178-181 ◽  
pp. 1117-1124 ◽  
Author(s):  
Chuan Qin Pang

Water is an important reason lead to the moisture damage on the asphalt pavements. In the paper, investigations and tests indicate that the poor permeability of the asphalt layer when the road opening to the traffic is a very common defect nowadays. The permeability would decrease under the hydraulic and air pressure resulted by moving vehicles, the water would directly penetrate the asphalt layer and accumulate at the interface betweens different layers. The precipitation water could also enter the pavement through the cracks and central separation belt, and accumulate as well, which lead to the development of moisture damage occurred at the bottom and upward subsequently. The intrude water also causes moisture failures in the base as well as the asphalt layer.


Coatings ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 178 ◽  
Author(s):  
Mulian Zheng ◽  
Yanjuan Tian ◽  
Litao He

The heat-reflective coating for asphalt pavement is a functional layer applied on pavement surfaces to reduce heat storage in the pavement via reflecting sunlight, thus inhibiting pavement temperature rise. The objective of this study was to analyze the environmental thermal effect of the self-developed reflective coating, namely, functionally graded nanocomposite reflective coatings, for asphalt pavement. The thermal effects of heat-reflective coatings were compared and analyzed based on field tests. A heating model of the atmosphere layer near the road surface was established. Moreover, the influence of urban road temperature on the thermal comfort of the human body was analyzed. Results showed that the radiation heat of all heat-reflective coatings decreased around two-thirds, and the convective heat decreased nearly 50% when compared with the control asphalt pavement, and the temperatures of the pavement itself and the atmosphere layer were lowered. Additionally, the heat-reflective coating improved the thermal comfort of the human body. This indicated that the heat-reflective coating reduced ambient temperate and relieved the urban heat island effect (UHI) as well as improved the environmental thermal effect.


2021 ◽  
Vol 13 (3) ◽  
pp. 1566
Author(s):  
Rong-Chang Jou ◽  
Ming-Che Chao

Introduction—Medical emergency vehicles help patients get to the hospital quickly. However, there were more and more ambulance crashes on the road in Taiwan during the last decade. This study investigated the characteristics of medical emergency vehicle crashes in Taiwan from January 2003 to December 2016. Methods—The ordered logit (OL) model, multinominal logit (MNL) model, and partial proportional odds (PPO) model were applied to investigate the relationship between the severity of ambulance crash injuries and its risk factors. Results—We found the various factors have different effects on the overall severity of ambulance crashes, such as ambulance drivers’ characteristics and road and weather conditions. When another car was involved in ambulance crashes, there was a disproportionate effect on the different overall severity, as found by the PPO model. Conclusions—The results showed that male ambulance drivers and car drivers who failed to yield to an ambulance had a higher risk of severe injury from ambulance crashes. Ambulance crashes are an emerging issue and need further policies and public education regarding Taiwan’s ambulance transportation safety.


2020 ◽  
pp. 002252662097950
Author(s):  
Fredrik Bertilsson

This article contributes to the research on the expansion of the Swedish post-war road network by illuminating the role of tourism in addition to political and industrial agendas. Specifically, it examines the “conceptual construction” of the Blue Highway, which currently stretches from the Atlantic Coast of Norway, traverses through Sweden and Finland, and enters into Russia. The focus is on Swedish governmental reports and national press between the 1950s and the 1970s. The article identifies three overlapping meanings attached to the Blue Highway: a political agenda of improving the relationships between the Nordic countries, industrial interests, and tourism. Political ambitions of Nordic community building were clearly pronounced at the onset of the project. Industrial actors depended on the road for the building of power plants and dams. The road became gradually more connected with the view of tourism as the motor of regional development.


2011 ◽  
Vol 194-196 ◽  
pp. 1632-1638
Author(s):  
Hong Liang Deng ◽  
Xiao Yin Fu ◽  
Wen Xue Gao ◽  
Ting Ting Ni ◽  
Kai Jiang Chen

The methods of controlling Highway semi-rigid base asphalt pavement cracks and other diseases are always hot fields of road engineering and academic circles. The existing methods are on some degree efficient on delaying the formation and extension of cracks, but the effect is limited with different methods and various mechanisms of preventing cracks. Base on force analysis of pavement, this article presents a new technology of crack controlling which uses intelligent composite materials interlayer. By adding a stress absorbing layer between the asphalt surface layers or the semi-rigid base layers with low modulus, good toughness, self-adaptability and self-control ability, the intelligent composite materials interlayer has a good effect on controlling cracks which has been proved by the theoretical calculations and experimental analysis. As a result, the intelligent composite materials interlayer could efficiently prevent and delay the formation and extension of cracks, the safety and comfort of highway could be improved significantly while the cost of construction and maintenance decreasing. And the service level and social image of the road could also be improved effectively. This research has important academic and application value.


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