scholarly journals Preparation Technique and Properties of Nano-TiO2 Photocatalytic Coatings for Asphalt Pavement

2018 ◽  
Vol 8 (11) ◽  
pp. 2049 ◽  
Author(s):  
Hui Wang ◽  
Ke Jin ◽  
Xinyu Dong ◽  
Shihao Zhan ◽  
Chenghu Liu
Keyword(s):  
Water Permeability ◽  
Degradation Rate ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Exhaust Gas ◽  
Preparation Technique ◽  
Tio2 Content ◽  
Nano Tio2 ◽  
Evaluation Indexes ◽  
Technical Requirements

According to the characteristics of asphalt pavement, a kind of nano-TiO2 photocatalytic coating was prepared by using the emulsified asphalt as the carrier. All of its properties met the technical requirements. An exhaust gas degradation test device and its test steps were developed. The evaluation indexes, cumulative degradation rate, and degradation efficiency, were put forward. From the two aspects of the nano-TiO2 content in photocatalytic coatings and the spraying amount of photocatalytic coatings in the surface of slabs (300 mm × 300 mm), the exhaust gas degradation effects, the performances of skid resistance, and the water permeability of asphalt mixture were analyzed. The test results showed that the cumulative degradation rate of exhaust gas was better when nano-TiO2 content was increased in the range of 0–8% and the spraying amount was changed in the range of 0–333.3 g/m2. In practical engineering applications, the anti-skid performance of asphalt pavement can be satisfied when the spraying amount of photocatalytic coating was limited to under 550 g/m2. The spraying amount of nano-TiO2 photocatalytic coating had little effect on the water permeability of the asphalt mixture. Therefore, 8% nano-TiO2 content in the coating and a 400 g/m2 spraying amount were finally recommended based on the photocatalytic properties, as well as for economic reasons.

scholarly journals Experimental Study on Photocatalytic Effect of Nano TiO2 Epoxy Emulsified Asphalt Mixture

2019 ◽  
Vol 9 (12) ◽  
pp. 2464 ◽  
Author(s):  
Ming Huang ◽  
Xuejun Wen
Keyword(s):  
Degradation Rate ◽  
Asphalt Mixture ◽  
Influence Factors ◽  
Tio2 Particle ◽  
Exhaust Gas ◽  
Vehicle Exhaust ◽  
Nano Tio2 ◽  
Photocatalytic Effect ◽  
Photocatalytic Material ◽  
Emulsified Asphalt

The two major problems that have plagued urban underground roads since their introduction are the harmful emissions caused by hot mix paving and vehicle exhaust accumulation during operation. In order to solve these two problems at the same time, a new asphalt mixture degrading automobile exhaust, which has the advantage of cold mix and cold-application, was presented and studied. A considerable amount of research shows that the use of titanium dioxide (TiO2) for pavements has received considerable attention in recent years to improve air quality near large metropolitan areas. However, the proper method of applying TiO2 to asphalt pavements is still unclear. The new mixture presented in this article contains epoxy emulsified asphalt as the binder; therefore, how to apply TiO2 in the special asphalt mixture proves to be the main focus. By experimental design, four influence factors on the photocatalytic effect, which are the nano-TiO2 particle sizes, dosage, degradation time, and light intensity, have been investigated. The experimental results showed that the 5-nm particle size of TiO2 is better than 10–15 nm for exhaust gas degradation, especially for HC and NO; with an increase in the amount of photocatalytic material, the degradation of CO and CO2 in the exhaust gas did not increase obviously, while the degradation effects of HC and NO were remarkable; in the 4-h time extended degradation test, the experimental data show that the extended time has little effect on the degradation rate of CO2 and CO, and the general trend is that the degradation of exhaust became significant with the extension of time; while setting a 2-h NO degradation rate as an indicator, to make the index more than 50% or 25%, the average illumination of the road surface cannot be less than 60 lx or 40 lx.

scholarly journals Fabrication and Evaluation of Nano-TiO2 Superhydrophobic Coating on Asphalt Pavement

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 211
Author(s):  
Hongfeng Li ◽  
Xiangwen Lin ◽  
Hongguang Wang
Keyword(s):  
Contact Angle ◽  
Stearic Acid ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Waterborne Polyurethane ◽  
Superhydrophobic Coating ◽  
Nano Tio2 ◽  
Sem Image ◽  
Low Surface Energy ◽  
Water Damage

In order to address water damage of asphalt pavement, reduce the occurrence of water-related potholes, deformation, and other diseases, and improve the performance and service life of the pavement, a nano-TiO2 superhydrophobic coating (PSC) on asphalt pavement was prepared from waterborne polyurethane and nano-TiO2 modified by stearic acid. FT-IR measured stearic acid successfully modified low surface energy substance on the surface of nano-TiO2. The SEM image shows that the PSC has a rough surface structure. The contact angle and rolling angle of the PSC in the contact angle test are 153.5° and 4.7°, respectively. PSC has a super-hydrophobic ability, which can improve the water stability of the asphalt mixture. Although the texture depth and pendulum value have been reduced by 2.5% and 4.4%, respectively, they all comply with the standard requirements. After the abrasion resistance test, the PSC coating still has a certain hydrophobic ability. These results surface PSC coating can effectively reduce water damage on asphalt pavement, and has considerable application value.

scholarly journals Influence of Heat Reflective Coating on the Cooling and Pavement Performance of Large Void Asphalt Pavement

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1065
Author(s):  
Nanxiang Zheng ◽  
Junan Lei ◽  
Shoubin Wang ◽  
Zhifeng Li ◽  
Xiaobao Chen
Keyword(s):  
Titanium Dioxide ◽  
Water Permeability ◽  
Performance Test ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Cooling Effect ◽  
Large Void ◽  
Reflective Coating ◽  
Water Permeability Coefficient ◽  
High Level

To reduce the temperature of asphalt pavement in summer, and alleviate the urban heat island effect, a comprehensive method of combining a heat reflective coating and large void asphalt pavement was proposed. Using the developed coating cooling test equipment, the cooling effect of the coating on a large void asphalt mixture was studied in six different proportions, four different colors, and four different dosages, and the durability of the coating was verified by abrasion tests. Finally, the best dosage of the coating was recommended through an adhesion test of the coating, and a water permeability and anti-skid performance test of the pavement. The results show that the reflectivity of the coating can be improved by adding functional fillers, of titanium dioxide and floating beads, into the coating. The order by reflectivity and cooling effect of the four color coatings was green > red > gray > blue, and the maximum cooling value of the green coating reached 9.7 ℃. The cooling performance of the coating decreased with the increase of wear time, and the rate of decrease was fast, then slow, and finally tended to be stable after 20,000 times wear. The coating reduced the anti-skid performance and the water permeability coefficient of large void asphalt pavement, but still maintained a high level. The green coating with 15% titanium dioxide and 10% floating beads is recommended as the cooling coating for large void asphalt pavement, and its dosage should be controlled at about 0.4–0.8 kg/m2.

A New Method to Measure the Gross Volume Density of the Asphalt Mixture Specimen - Brush Wax Method

2014 ◽  
Vol 505-506 ◽  
pp. 154-162
Author(s):  
Long Shi Peng ◽  
Min Gong ◽  
Lan Qiao
Keyword(s):  
Quality Control ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Volume Density ◽  
Test Method ◽  
The Other ◽  
New Method ◽  
Practical Significance ◽  
Technical Requirements

The gross volume density of mix asphalt material compacted specimen is a crucial indicator in the design of asphalt mixture and quality control of asphalt pavement, and it directly determines the asphalt aggregate ratio and the degree of compaction. It has a great practical significance to distinguish and choose the test method of gross volume density correctly. The specific aspects of the methods to determine gross volume density have been controversial. A new method named brush wax method is put forward for these issues. The density, priority, VMA and compactness of asphalt mixture were measured by different methods in the tests. By comparison of the new method and the other methods, the main technical indexes of asphalt mixture obtained by the brush wax method are the only one which greatly satisfies the technical requirements.

Study on Technical Index of Raw Material for Tianjin Permeable Asphalt Pavement

2014 ◽  
Vol 638-640 ◽  
pp. 1207-1210
Author(s):  
Sheng Guan Di ◽  
Teng Teng Guo ◽  
Xin Qi Wang ◽  
Chao Hui Wang
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Service Performance ◽  
Raw Material ◽  
Permeable Pavement ◽  
Technical Requirements ◽  
Climatic Characteristics

According to the problem that the cohesiveness and durability of permeable asphalt pavement is poorer than common dense gradation asphalt mixtures, on the premise of improving the permeability, in order to meet the service performance and durability of permeable asphalt pavement, through the investigation of technical requirements on permeable asphalt pavement raw material in Japan and several endemic standards of China where permeable pavement technology is mature, combined with climatic characteristics in Tianjin, the technical requirements suggested values of permeable asphalt mixture suitable for Tianjin are put forward.

scholarly journals 2D-wavelet based micro and macro texture analysis for asphalt pavement under snow or ice condition

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Feng Li ◽  
Gulnigar Ablat ◽  
Siqi Zhou ◽  
Yixin Liu ◽  
Yufeng Bi ◽  
...  
Keyword(s):  
Wavelet Transform ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Micro Scale ◽  
Braking System ◽  
Macro Scale ◽  
Texture Characteristics ◽  
The Mean ◽  
Resistance Performance

AbstractIn ice and snow weather, the surface texture characteristics of asphalt pavement change, which will significantly affect the skid resistance performance of asphalt pavement. In this study, five asphalt mixture types of AC-5, AC-13, AC-16, SMA-13, SMA-16 were prepared under three conditions of the original state, ice and snow. In this paper, a 2D-wavelet transform approach is proposed to characterize the micro and macro texture of pavement. The Normalized Energy (NE) is proposed to describe the pavement texture quantitatively. Compared with the mean texture depth (MTD), NE has the advantages of full coverage, full automation and wide analytical scale. The results show that snow increases the micro-scale texture because of its fluffiness, while the formation of the ice sheets on the surface reduces the micro-scale texture. The filling effect of snow and ice reduces the macro-scale texture of the pavement surface. In a follow-up study, the 2D-wavelet transform approach can be applied to improve the intelligent driving braking system, which can provide pavement texture information for the safe braking strategy of driverless vehicles.

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.

Sign in / Sign up

Export Citation Format

Share Document