scholarly journals An Analysis on the Effectiveness of Nitrogen Oxide Reduction from Applying Titanium Dioxide on Urban Roads Using a Statistical Method

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 972
Author(s):  
Sang-Hyuk Lee ◽  
Jong-Won Lee ◽  
Moon-Kyung Kim ◽  
Hee-Mun Park
Keyword(s):  
Titanium Dioxide ◽  
Nitrogen Oxide ◽  
Statistical Method ◽  
Test Section ◽  
Photochemical Reaction ◽  
Asphalt Pavement ◽  
Type Form ◽  
Average Probability ◽  
Anderson Darling ◽  
Reference Section

The purpose of this study was to analyze the effect of titanium dioxide (TiO2) on reducing nitrogen oxide (NOx) concentrations using the statistical method of the Anderson-Darling test. To compare and analyze this effect, a spray-type form of TiO2 was applied to the asphalt pavement surface on urban roads. Data acquisition for NOx concentration was collected from a test section with TiO2 applied and a reference section without TiO2 applied. The probabilities of occurrence of the NOx concentration in the test and reference section were estimated and compared using the Anderson-Darling test. In sum, most of the NOx concentrations were probabilistically lower in the test section. The average probability of the NOx concentration in the test section in the ‘low’ range was 46.2% higher than in the reference section. In the ‘high’ and ‘moderate’ ranges, the average probability of the NOx concentration compared to that of the reference section was lower by 28.1% and 18.8%, respectively. These results revealed that the photochemical reaction from the TiO2 material applied on asphalt pavement was effective in reducing NOx.

scholarly journals Effect of Thickness of Gravel Base and Asphalt Pavement on Road Deformation

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Dongliang He ◽  
Weijun Yang
Keyword(s):  
Numerical Calculation ◽  
Test Section ◽  
Asphalt Pavement ◽  
Road Surface ◽  
Vertical Deformation ◽  
The Road ◽  
Design Requirements ◽  
The Relationship

This study uses a test section of a highway, a study object, to explore the effect of thickness of the gravel base and asphalt layer on the vertical deformation of the road surface. The thickness of the asphalt layer and graded gravel base is changed. The nonlinear description equation of the relationship between the thickness (h1) of the asphalt layer and the vertical deformation (d1) is established: d1=a41−b4h1. The thickness of the asphalt pavement is then determined to reduce vertical deformation. Numerical calculation shows that the maximum vertical deformation of the foundation is within 8 mm, which is less than the 15 mm maximum vertical deformation of the embankment. This level meets the design requirements.

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.

22. Mergers (3): UK

2021 ◽  
pp. 959-1018
Author(s):  
Richard Whish ◽  
David Bailey
Keyword(s):  
Public Interest ◽  
Test Section ◽  
Merger Control ◽  
Phase 2 ◽  
Special Cases ◽  
One Stop ◽  
Control Section ◽  
The Uk ◽  
Reference Section ◽  
The Eu

This chapter discusses UK law on the control of mergers. The chapter is organized as follows. Section 2 provides an overview of the domestic system of merger control. Section 3 explains the procedure of the Competition and Markets Authority (CMA) when determining whether a merger should be referred for an in-depth ‘Phase 2’ investigation and when deciding to accept ‘undertakings in lieu’ of a reference. Section 4 describes how Phase 2 investigations are conducted and Section 5 discusses the ‘substantially lessening competition’ (‘SLC’) test. Section 6 explains the enforcement powers in the Enterprise Act 2002, including the remedies that the CMA can impose in merger cases. The subsequent sections discuss various supplementary matters, such as powers of investigation and enforcement. The chapter concludes with a discussion of how the merger control provisions work in practice and a brief account of the provisions on public interest cases, other special cases and mergers in the water industry. The withdrawal by the UK from the EU means that many mergers that were subject to a ‘one-stop shop’ under EU law are now subject to investigation in the UK as well.

scholarly journals Development of a Mechanistic Method to Obtain Load Position Strain in Instrumented Pavement

Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 14
Author(s):  
Guiling Hu ◽  
Wenyang Han ◽  
Jincheng Wei ◽  
Deqing Wang ◽  
Xiaomeng Zhang ◽  
...  
Keyword(s):  
Test Section ◽  
Asphalt Pavement ◽  
Strain Sensors ◽  
Absolute Difference ◽  
Positioning System ◽  
Calculated Load ◽  
And Performance ◽  
Response Collection ◽  
Lateral Axis

To study the in-situ response and performance of asphalt pavement, instrumenting pavement with a variety of sensors has become one of the most important tools in the field or accelerated load facilities. In the dynamic response collection process, engineers are more concerned with the load position strain of the pavement structure due to wheel wander. This paper proposes a method to obtain the load position and the strain at the load position when there is no lateral-axis positioning system based on multilayer elastic theory. The test section was paved in the field with installed strain sensors to verify and apply the proposed method. The verification results showed that both the calculated load position and load position strain matched the measured values with an absolute difference range of 5–60 mm, 0.5–2.5 με, respectively. The application results showed that the strain at the load position calculated by the proposed method had a good correlation with the temperature, as expected.

scholarly journals Pollution-absorbing pavement and proposals for the application in Vietnam

2021 ◽  
Vol 63 (3) ◽  
pp. 33-36
Author(s):  
Van Nam Nguyen ◽  
◽  
Duc Sy Vu ◽  
Huy Khang Pham ◽  
◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Asphalt Pavement ◽  
Developed Countries ◽  
Tio2 Photocatalyst ◽  
Research Results ◽  
The World

The pollution-absorbing pavement using titanium dioxide (TiO2) photocatalyst additive has been studied and applied in many developed countries around the world. However, this type of pavement has not been studied and applied in Vietnam until the present. This paper presents the research results for the pollution-absorbing asphalt pavement carried out in Vietnamese conditions to provide proposals and recommendations for the application of this pavement in Vietnam.

Georgia’s Experience with Recycled Roofing Shingles in Asphaltic Concrete

1998 ◽  
Vol 1638 (1) ◽  
pp. 129-133 ◽  
Author(s):  
Donald E. Watson ◽  
Andrew Johnson ◽  
Hem R. Sharma
Keyword(s):  
Test Section ◽  
Building Materials ◽  
Asphalt Pavement ◽  
Cost Savings ◽  
Reclaimed Asphalt Pavement ◽  
Fine Aggregate ◽  
Asphaltic Concrete ◽  
Department Of Transportation ◽  
Reclaimed Asphalt ◽  
Asphalt Cement

Reuse of roofing shingle waste not only minimizes the environmental problems related to the disposal of waste in landfills, but also reduces the amount of virgin asphalt cement and fine aggregate required in hot mix asphaltic concrete (HMAC), thus creating the potential for cost savings. The Georgia Department of Transportation (GDOT) has experimented with the recycling of roofing shingles in HMAC by constructing two test sections in 1994 and 1995. The source of the roofing shingles used in both test sections was waste generated by a roofing manufacturer; this generally consisted of discolored or damaged shingles. One test section was constructed on Chatham Parkway in Chatham County and one on State Route 21 in Effingham County. GAF Building Materials, Inc., located in Savannah, provided the waste shingle material; APAC Georgia, Inc., also located in Savannah, produced and placed these experimental mixtures. To date, both test sections are performing well compared with the unmodified control sections. Based on the performance of these test sections, shingle manufacturing waste is allowed as a recycling material in HMAC, just as reclaimed asphalt pavement is, for GDOT projects. A specification allowing postconsumer roofing shingle waste to be used is also being proposed.

scholarly journals Evaluation of thin flexible pavements under simulated aircraft traffic

2020 ◽  
Author(s):  
W. Robinson
Keyword(s):  
Test Section ◽  
Asphalt Pavement ◽  
Concrete Surface ◽  
Tire Pressure ◽  
Test Items ◽  
Pavement Structures ◽  
And Performance ◽  
Rutting Behavior ◽  
Aggregate Base ◽  
Falling Weight

A full-scale airfield pavement test section was constructed and trafficked by the U.S. Army Engineer Research and Development Center (ERDC) to evaluate the performance of relatively thin airfield pavement structures. The test section consisted of 16 test items that included three asphalt pavement thicknesses and two different aggregate base courses. The test items were subjected to simulated aircraft traffic to evaluate their response and performance to realistic aircraft loads and to evaluate the effect of reductions in tire pressure on thin asphalt pavement. Rutting behavior, pavement cracking, instrumentation response, and falling weight deflectometer response were monitored at selected traffic intervals. The results of this study were used to extend existing Department of Defense pavement design and evaluation techniques to include the evaluation of airfield pavement sections that do not meet the current criteria for aggregate base quality and minimum asphalt concrete surface thickness. These performance data were used to develop new aggregate base failure design curves using existing stress-based design methodology.

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