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

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.

2018 ◽  
Vol 8 (11) ◽  
pp. 2049 ◽  
Author(s):  
Hui Wang ◽  
Ke Jin ◽  
Xinyu Dong ◽  
Shihao Zhan ◽  
Chenghu Liu

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.


2015 ◽  
Vol 16 (3) ◽  
pp. 716-726 ◽  
Author(s):  
Xuejuan Cao ◽  
Boming Tang ◽  
Xiaoling Zou ◽  
Lihong He

2013 ◽  
Vol 723 ◽  
pp. 171-176
Author(s):  
Fei Chen ◽  
Ming Chen

in this paper the surface temperature of test specimens which were water-saturated were measured after different exposure time in the lamplight. The relationship can be set up among surface temperature,air viods and water permeability coefficient. This research demonstrated that there is good correlation. So when the pavement is in the sunshine for a time after a rain,asphalt pavement areas with different water permeability coefficient can be distinguished by using infra-red technology to measure the surface temperature.Compaction of asphalt pavement can also be evaluated. This way was used and checked up in shanghai-chengdu highway project. This is a new method what is very convinently and quickly to evaluate the compaction and homogeneity of asphalt pavement.


2019 ◽  
Vol 9 (10) ◽  
pp. 1988 ◽  
Author(s):  
Jiyu Xin ◽  
Jianzhong Pei ◽  
Mitsuyoshi Akiyama ◽  
Rui Li ◽  
Jiupeng Zhang ◽  
...  

Generally, various kinds of cracks are the main type of distresses during the service period of asphalt pavements. To save maintenance costs and improve the crack resistance of asphalt pavements effectively, this paper presents a unique design method for the material composition of small particle-size (SPS) asphalt mixture for controlling cracks in asphalt pavement. First, Stone Mastic Asphalt (SMA)-II was designed as a basic gradation according to the A.N. Talbot curve and SMA-II-1, SMA-II-2 and SMA-II-3 were designed according to the Superpave mix design method, the Bailey method and the Particle interference theory, respectively. Second, based on Marshall test results, the optimal fiber content and optimal asphalt content of three gradations were determined. Then, the influence of the passing rate of 1.18-mm sieve and 0.075-mm sieve on the air voids of SMA-II and the influence of the filler-asphalt ratio on the performance of SMA-II were investigated, and an appropriate range of filler-asphalt ratio was obtained. Finally, a high-temperature performance test, a water stability test, and a skid resistance test demonstrate that the overall performance of SMA-II can satisfy the specifications. A low-temperature bend test and analysis of bending strain energy density show that SMA-II with a crumb rubber modifier and a polymer fiber has better crack resistance performance than SMA-I (SBS-modified mixture). Life-cycle cost analysis shows the economic advantage of SPS asphalt thin overlays over traditional AC-13 thin overlays.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jiarong Wang ◽  
Zhengqi Zhang ◽  
Datong Guo ◽  
Cheng Xu ◽  
Ke Zhang

To reduce the temperature of asphalt pavement and improve the antirutting performance of asphalt mixture, a thermal-resistant asphalt mixture (TRAM) was produced, in which a certain proportion of mineral aggregate was replaced by ceramic (CE) or floating beads (FB) featuring low thermal conductivity. Firstly, a parallel plate test was developed to test the thermal conductivity of asphalt mixture added with different thermal-resistant materials. Secondly, the illumination test system was designed to study the visual cooling effect of different TRAM by imitating the natural environment. Finally, the effect of different thermal-resistant materials on asphalt pavement performance was evaluated. The results show that the addition of thermal-resistant materials can reduce the thermal conductivity and the temperature of asphalt mixture. The cooling effect of CE75 and CE100 (coarse aggregate substituted by 75% and 100% CE, respectively) is superior to other aggregates. The temperature reduction rates of CE75 and CE100 reache 6.6°C and 6.8°C, respectively. For FB50 and FB75 (fine aggregate substituted with 50 and 75% FB, respectively), the cooling effect of them reaches 3.9°C and 4.5°C, respectively. In addition, the CE and FB can improve the antirutting performance of asphalt mixture by reducing the temperature inside the pavement. The high-temperature performance of CE75 and FB75 is the best. With the increase of thermal resistance materials, the low-temperature cracking resistance of asphalt mixture decreases gradually. The failure strain of mixture added with 100% thermal resistance materials is close to the lower limit of Chinese specification. The water stability of different TRAM changes with various test methods. Taking into account the results of pavement performance and the cooling effect, the substitution proportion of CE and FB for TRAM is proposed as 50%∼75%, respectively.


Author(s):  
Pengzhen Lu ◽  
Chenhao Zhou ◽  
Simin Huang ◽  
Yang Shen ◽  
Yilong Pan

Expansion joints are a weak and fragile part of bridge superstructure. The damage or failure of the expansion joint will lead to the decline of bridge durability and endanger the bridge structure and traffic safety. To improve the service life and performance of bridge expansion joints, the ideal method is to use seamless expansion joints. In this study, starting from the commonly used asphalt mixture gradation of seamless expansion joint, and taking into account the actual situation of bridge expansion joint structure and environment in China, the gradation and asphalt-aggregate ratio are preliminarily designed. Through a Marshall test, the corresponding asphalt mixture is evaluated and analyzed according to the stability, flow value, and void ratio, and the optimal gradation and asphalt-aggregate ratio are determined. Finally, the asphalt mixture is prepared with the mixture ratio design, and the test results of an immersion Marshall test, fatigue performance test, and full-scale test verify that the asphalt mixture meets the road performance requirements of seamless expansion joints. On the basis of the experimental data, the performance of large sample asphalt mixture is continuously tested, compared, and optimized. The results show that the asphalt mixture ratio designed is true and reliable, which can provide reference for the optimal design of seamless expansion joint filler.


Author(s):  
Feng Li ◽  
Gulnigar Ablat ◽  
Siqi Zhou ◽  
Yixin Liu ◽  
Yufeng Bi ◽  
...  

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.


Author(s):  
Maciej Gliniak ◽  
Jakub Sikora ◽  
Urszula Sadowska ◽  
Agnieszka Klimek-Kopyra ◽  
Agnieszka Latawiec ◽  
...  

Author(s):  
Amir Golalipour ◽  
Varun Veginati ◽  
David J. Mensching

In the asphalt materials community, the most critical research need is centered around a paradigm shift in mixture design from the volumetric process of the previous 20-plus years to an optimization procedure based on laboratory-measured mechanical properties that should lead to an increase in long-term pavement performance. This study is focused on advancing the state of understanding with respect to the value of intermediate temperature cracking tests, which may be included in a balanced mix design. The materials included are plant-mixed, laboratory-compacted specimens reheated from the 2013 Federal Highway Administration’s (FHWA’s) Accelerated Loading Facility (ALF) study on reclaimed asphalt pavement/reclaimed asphalt shingle (RAP/RAS) materials. Six commonly discussed intermediate temperature (cracking and durability) performance testing (i.e., Asphalt Mixture Performance Tester [AMPT] Cyclic Fatigue, Cantabro, Illinois Flexibility Index Test [I-FIT], Indirect Tensile Cracking [ITC, also known as IDEAL-CT], Indirect Tensile Nflex, and Texas Overlay Test) were selected for use in this study based on input from stakeholders. Test results were analyzed to compare differences between the cracking tests. In addition, statistical analyses were conducted to assess the separation among materials (lanes) for each performance test. Cyclic fatigue and IDEAL-CT tests showed the most promising results. The ranking from these two tests’ index parameters matched closely with ALF field performance. Furthermore, both showed reasonable variability of test data and they were successful in differentiating between different materials.


Sign in / Sign up

Export Citation Format

Share Document