scholarly journals A Study on Heat Storage and Dissipation Efficiency at Permeable Road Pavements

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3431
Author(s):  
Ching-Che Yang ◽  
Jun-Han Siao ◽  
Wen-Cheng Yeh ◽  
Yu-Min Wang
Keyword(s):  
Heat Dissipation ◽  
Heat Storage ◽  
Permeable Pavement ◽  
Pavement Materials ◽  
Road Pavement ◽  
Hourly Temperature ◽  
Different Types ◽  
Urban Heat ◽  
Base Course ◽  
Design Depth

The main contributing factor of the urban heat island (UHI) effect is caused by daytime heating. Traditional pavements in cities aggravate the UHI effect due to their heat storage and volumetric heat capacity. In order to alleviate UHI, this study aims to understand the heating and dissipating process of different types of permeable road pavements. The Ke Da Road in Pingtung County of Taiwan has a permeable pavement materials experiment zone with two different section configurations which were named as section I and section II for semi-permeable pavement and fully permeable pavement, respectively. The temperature sensors were installed during construction at the depths of the surface course (0 cm and 5 cm), base course (30 cm and 55 cm) and subgrade (70 cm) to monitor the temperature variations in the permeable road pavements. Hourly temperature and weather station data in January and June 2017 were collected for analysis. Based on these collected data, heat storage and dissipation efficiencies with respect to depth have been modelled by using multi regression for the two studied pavement types. It is found that the fully permeable pavement has higher heat storage and heat dissipation efficiencies than semi-permeable pavement in winter and summer monitoring period. By observing the regressed model, it is found that the slope of the model lines are almost flat after the depth of 30 cm. Thus, from the view point of UHI, one can conclude that the reasonable design depth of permeable road pavement could be 30 cm.

Contrastive Studies of Asphalt Pavement on Suction Exothermic Properties and Cooling Measures

2011 ◽  
Vol 97-98 ◽  
pp. 290-296
Author(s):  
Wei Guang Li ◽  
Zhi Dong Han ◽  
Zhen Bei Lv ◽  
Yan Hong Duan
Keyword(s):  
Heat Storage ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Heat Island ◽  
Regular Pattern ◽  
Island Effect ◽  
Different Types ◽  
Urban Heat ◽  
Pavement Structure ◽  
Quantity Of Heat

It is important to reduce asphalt mixture strong absorption characteristics to improve anti-rutting ability and reduce the urban heat island effect. This paper firstly studies the suction and exothermic regular pattern of existing three types, five kinds of asphalt pavement structure. It turns out that there are differences in suction and exothermic characteristics of different types of pavement structure. Suspension close-grained type structure has higher adiabatic heating; gap-type skeleton has faster speed of suction and exothermic; and dense skeleton has more total quantity of heat storage. Accordingly, test and analysis of cooling effect of Gap-type skeleton asphalt pavement has conducted by adopting smear reflective materials to reduce reflectance and surface adding insulation materials, The results show that reducing reflectivity is the best way which can reduce by 5 centigrade around. In addition , improving effectiveness has also been studied by adding light-colored stone partly replacing mineral aggregate, and substituting busing mullite for aggregate below2.36 mm is the best cooling way ,which can reduce by 3.3 centigrade.

scholarly journals Research on the Properties of Mineral–Cement Emulsion Mixtures Using Recycled Road Pavement Materials

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 563
Author(s):  
Łukasz Skotnicki ◽  
Jarosław Kuźniewski ◽  
Antoni Szydło
Keyword(s):  
Road Construction ◽  
Base Layer ◽  
Asphalt Emulsion ◽  
Reclaimed Asphalt ◽  
Pavement Materials ◽  
Road Pavement ◽  
Road Surfaces ◽  
Cement Binder ◽  
Pavement Structures ◽  
By Products

The reduction in natural resources and aspects of environmental protection necessitate alternative uses of waste materials in the area of construction. Recycling is also observed in road construction where mineral–cement emulsion (MCE) mixtures are applied. The MCE mix is a conglomerate that can be used to make the base layer in road pavement structures. MCE mixes contain reclaimed asphalt from old, degraded road surfaces, aggregate improving the gradation, asphalt emulsion, and cement as a binder. The use of these ingredients, especially cement, can cause shrinkage and cracks in road layers. The article presents selected issues related to the problem of cracking in MCE mixtures. The authors of the study focused on reducing the cracking phenomenon in MCE mixes by using an innovative cement binder with recycled materials. The innovative cement binder based on dusty by-products from cement plants also contributes to the optimization of the recycling process in road surfaces. The research was carried out in the field of stiffness, fatigue life, crack resistance, and shrinkage analysis of mineral–cement emulsion mixes. It was found that it was possible to reduce the stiffness and the cracking in MCE mixes. The use of innovative binders will positively affect the durability of road pavements.

scholarly journals The Limestone as a Materials Combination of Base Course on the Road Pavement

2021 ◽  
Vol 1125 (1) ◽  
pp. 012019
Author(s):  
Yosef Cahyo Setianto Poernomo ◽  
Sigit Winarto ◽  
Zendy Bima Mahardana ◽  
Dwifi Aprillia Karisma ◽  
Rekso Ajiono
Keyword(s):  
The Road ◽  
Road Pavement ◽  
Base Course ◽  
On The Road

An analysis of urban heat island impact toward increasing of afternoon thunderstorm frequency in Taipei, Taiwan

2021 ◽  
Author(s):  
Siti Talitha Rachma ◽  
Yuan-Chien Lin
Keyword(s):  
Urban Heat Island ◽  
Empirical Orthogonal Function ◽  
Precipitation Pattern ◽  
Heat Island ◽  
Hilbert Huang Transform ◽  
Orthogonal Function ◽  
Hourly Temperature ◽  
Taipei City ◽  
The Future ◽  
Urban Heat

<p>Each year, average of Earth’s temperature rises and the urbanized cities, are warming at a significant rate than the surrounding rural areas. This phenomenon is called Urban Heat Island (UHI). UHI is a consequence of human activities in urban area and it has possibilities to impact weather and climate on regional or global scale. Precipitation is one of the basic hydro-meteorological phenomena that could be affected by UHI trend with thunderstorm as a part of precipitation. As the UHI level rises from year to year, the pattern of precipitation could change. However, this issue is still underdeveloped, thus, this work tries to comprehensively understand the hydrological response to UHI.</p><p> </p><p>This research selects Taipei city as the study area and explores the connection between UHI and precipitation pattern’s change. The data used here are hourly temperature and precipitation data collected from 21 Taipei weather stations collected from Central Weather Bureau (CWB) Taiwan. In order to reveal specific details and trend of non-linear relation from both time domain and frequency, Hilbert-Huang Transform (HHT) is adopted in this study. The HHT results are compared between each station. Later, empirical orthogonal function (EOF) also being used to extract main spatial pattern of precipitation in Taipei city.</p><p> </p><p>The results show that the urbanization in Taipei city contribute to increasing trend of 0.5 – 1 <sup>o</sup>C in daily UHI and also increase of 27% in the afternoon thunderstorm frequency for this past 20 years. The increase of thunderstorm would result into a bigger rain water flow to the river and a fewer time for it to percolate to the ground. If there are more thunderstorms in the future, it is possible the phenomenon could lead to the lack of groundwater discharge and depletion of groundwater reserve. This result could be utilized in the future to understand more about UHI mitigation and thunderstorm in Taipei.</p><p> </p><p>Keywords: urban heat island, thunderstorm, Hilbert-Huang Transform, empirical orthogonal function</p>

scholarly journals A Numerical Study on Mitigation Strategies of Urban Heat Islands in a Tropical Megacity: A Case Study in Kaohsiung City, Taiwan

2020 ◽  
Vol 12 (10) ◽  
pp. 3952 ◽  
Author(s):  
Jou-Man Huang ◽  
Liang-Chun Chen
Keyword(s):  
Thermal Environment ◽  
Numerical Study ◽  
Mitigation Strategies ◽  
Comfort Level ◽  
Tropical Region ◽  
Permeable Pavement ◽  
Coverage Ratio ◽  
Urban Heat ◽  
Cooling Effects

In recent years, with the rapid increase in global warming and urbanization, urban heat island effects (UHI) have become an important environmental issue. Taiwan is no exception, with previous studies demonstrating serious UHIs in megacities. Although existing UHI research has utilized computer simulations to analyze improvement scenarios, there are few cooling strategy studies in actual blocks of Taiwan. Therefore, this study selected a block of a megacity in a tropical region of Taiwan as a case study by ENVI-met. Five improvement strategies were tested and compared to the current situation (B0): (1) Case C1 changed to permeable pavement, (2) Case C2 increased the green coverage ratio (GCR) of the street to 60%, (3) Case C3 changed to permeable pavement and increased the GCR in the street to 60%, (4) Case C4 changed to permeable pavement, increased the GCR in the street to 60%, and increased the GCR in the parks to 80%, and (5) Case C5 changed to permeable pavement, increased GCR in the street to 60% and parks to 80%, and set the GCR on the roof of public buildings to 100%. The results showed that the average temperature of the current thermal environment is 36.0 °C, with the comfort level described as very hot. Among the five improvement schemes, C5 had the greatest effect, cooling the area by an average of 2.00 °C. Further analysis of the relationship between the different GCRs of streets (SGCR) and the cooling effects revealed that for every 10% increase in the SGCR, the temperature of the pedestrian layer was reduced by 0.15 °C.

scholarly journals Green Infrastructure as an Urban Heat Island Mitigation Strategy—A Review

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3577
Author(s):  
Fatma Balany ◽  
Anne WM Ng ◽  
Nitin Muttil ◽  
Shobha Muthukumaran ◽  
Man Sing Wong
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Green Infrastructure ◽  
Mitigation Strategies ◽  
Heat Island ◽  
Recent Past ◽  
Simulation Tools ◽  
Human Thermal Comfort ◽  
Different Types ◽  
Urban Heat

Research on urban heat mitigation has been growing in recent years with many of the studies focusing on green infrastructure (GI) as a strategy to mitigate the adverse effects of an urban heat island (UHI). This paper aims at presenting a review of the range of findings from GI research for urban heat mitigation through a review of scientific articles published during the years 2009–2020. This research includes a review of the different types of GI and its contribution for urban heat mitigation and human thermal comfort. In addition to analysing different mitigation strategies, numerical simulation tools that are commonly used are also reviewed. It is seen that ENVI-met is one of the modelling tools that is considered as a reliable to simulate different mitigation strategies and hence has been widely used in the recent past. Considering its popularity in urban microclimate studies, this article also provides a review of ENVI-met simulation results that were reported in the reviewed papers. It was observed that the majority of the research was conducted on a limited spatial scale and focused on temperature and human thermal comfort.

Microscale Heat Island Characterization of Rigid Pavements

2017 ◽  
Vol 2639 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Sushobhan Sen ◽  
Jeffery Roesler
Keyword(s):  
Radiative Forcing ◽  
Time Lag ◽  
Thermal Inertia ◽  
Concrete Pavements ◽  
Heat Island ◽  
Rigid Pavements ◽  
Subsurface Layers ◽  
Urban Heat ◽  
Base Course

Rigid pavements have an impact on the urban heat island (UHI) and hence the surrounding environment and human comfort. Currently, most studies use a mesoscale approach in UHI characterization of pavements. This study proposes a microscale approach that can be incorporated into a pavement life-cycle assessment (LCA). The heat flux of various concrete pavements containing layers of varying thermal diffusivity and inertia was simulated. The surface pavement radiative forcing (RFp) was developed as a metric for use in a pavement LCA. Additionally, the heat conducted and stored in each concrete pavement system was analyzed using an average seasonal day metric to understand the temporal pavement energetics. Of the various thermal cases, only a higher albedo surface significantly changed the RFp for a fixed climate. However, a time lag was induced by the thermal inertia of the base course, which decreased the amount of heat conducted out of the pavement at night by storing heat in the base course for a longer time, effectively reducing nighttime UHI. Diurnal variations in thermal behavior can be controlled by changing the thermal properties of subsurface layers, which can be used to partially mitigate UHI.

scholarly journals Comparison of Potential Contribution of Typical Pavement Materials to Heat Island Effect

2020 ◽  
Vol 12 (11) ◽  
pp. 4752 ◽  
Author(s):  
Hailu Yang ◽  
Kai Yang ◽  
Yinghao Miao ◽  
Linbing Wang ◽  
Chen Ye
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Potential Contribution ◽  
Heat Island ◽  
Cement Concrete ◽  
Porous Asphalt ◽  
Pavement Materials ◽  
Island Effect ◽  
Urban Heat ◽  
Better Than

Pavement materials have significant influence on the urban heat island effect (UHIE). This paper presents a study on the potential effects of pavement materials on UHIE in a natural environment. Three typical pavement materials, including cement concrete, dense asphalt concrete and porous asphalt mixture, were selected to evaluate their anti-UHIE properties by testing. In this paper, heat island potential (HIP) is proposed as a new index to analyze the influence of pavement materials on UHIE. It is shown that the temperature inside a pavement distinctly depends on the depth, and varies, but is usually higher than the air temperature. Solar radiation in the daytime significantly contributes to the temperature of pavement surface and the upper part. The correlation becomes weak at the middle and the bottom of pavements. Among the three materials tested in this study, the anti-UHIE performance of cement concrete is significantly higher than that of the other asphalt mixtures, while the porous asphalt mixture is slightly better than the dense asphalt concrete in anti-UHIE.

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