A comparison of thermal performance of different pavement materials

doi:10.1016/B978-1-78242-380-5.00004-2

Eco-Efficient Materials for Mitigating Building Cooling Needs

Design, Properties and Applications

2015, Pages 63-124

Eco-Efficient Materials for Mitigating Building Cooling Needs

https://doi.org/10.1016/B978-1-78242-380-5.00004-2 Get rights and content

Abstract

This chapter discusses the thermal performance of different pavement types commonly used, including permeable and nonpermeable concrete material, asphalt material, and block paver. The chapter first introduces the important material properties such as albedo and thermal properties of different pavement materials. The chapter then discusses the thermal performance of different pavement materials, including pavement surface temperature, near-surface air temperature above pavement, thermal impact of pavement on nearby building surfaces, and heat flux from pavement. Potential impacts of pavements and future trends are also discussed.

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Cited by (21)

Evaluation of microclimate mitigation strategies in a heterogenous street canyon in Kuala Lumpur from outdoor thermal comfort perspective using Envi-met
2023, Urban Climate
Assessing the efficacy of mitigation measures for the improvement of the daytime microclimate has been advised extensively, especially in hot and humid tropical regions as an effort to a) reduce the cooling demand of buildings and b) enhance outdoor livability by improving the thermal comfort of pedestrians. The latter has been investigated in this research based on microclimatic and urban characteristics of a developed commercial street in Kuala Lumpur, Malaysia and by utilization of field measurements and parametric simulations. The evaluated area is within a street canyon with heterogeneity in its urban components and building design with various heights and façade materials; being distinguished from the uniform or open-set urban complexes which had been assessed in the previous studies.
Five mitigating scenarios were adopted using Envi-met V4.6 simulation software to investigate their influence on air temperature (Ta), surface temperature (Ts), mean radiant temperature (Tmrt), and physiological equivalent temperature (PET) in the study area during peak hours of the day from 11:00 to 16:00. Among the high albedo façade, high reflective ground surfaces, permeable pavement, extra tree coverage, and a mixture of the last two measures, it is identified that the application of permeable pavements and added tree resulted in maximum PET improvement along with Ta, Tmrt, and Ts reductions. The study also shows that increasing the albedo of facades despite a negligible impact in reducing Ta, causes PET to worsen; the same results were obtained regarding high reflective pavements and roads, although significant Ts reduction occurred through this method. The research concludes that considering the tropical climate of Kuala Lumpur with abundant solar radiation and rainfall, for narrow streets with variation in components and high-rise buildings, implementation of permeable pavement on sidewalks and open parking areas not only contribute to alleviating urban warming effects but can potentially manage stormwater runoff as well.
A novel application of the geothermal asphalt pavement: A feasible E-fuel source
2023, Transportation Engineering
In this study, a novel application of geothermal technology was proposed and evaluated as a potential sustainable clean energy source. The proposed system incorporates thermoelectric generators (TEG) to transform the extracted heat from the pavement into electricity and enclose an enhanced geothermal system into the asphalt structure, intending to cool the pavement surface and provide the thermal gradient required for energy harvesting simultaneously. The study hypothesized the amplification of the thermal gradient through geothermal pipes embedded in the asphalt layer, a phase change material container in the subgrade, and an external cooling system in direct contact with the TEGs. A comprehensive experimental study was conducted to evaluate the thermal, electrical, and structural performance of the proposed geothermo-electrical asphalt pavement system. Also, a large-scale experimental physical model was established to simulate and assess the system's performance under real-life conditions. By monitoring the system's performance over six consecutive days, the results showed that the enhanced geothermal system efficiently reduced the surface temperature of the asphalt pavement by 40% and sustained a thermal gradient of around 40 °C, which was sufficient to sustainably harvest energy through using the TEGs. The harvested energy was then successfully used to charge an attached battery. The results of this study demonstrate the feasibility and potential of using geothermal technology in asphalt pavements as a sustainable energy source. Furthermore, the proposed system not only improves the performance of the pavements in terms of structural behavior but also introduces a new way of energy harvesting, opening the door for new possibilities in the renewable energy field.
Semi-flexible pavement with glass for alleviating the heat island effect
2023, Construction and Building Materials
This study investigated the feasibility of developing a semi-flexible pavement (SFP) by utilising recycled waste glass to partially replace ingredients in traditional asphalt pavement and the effect on performance. The results established that partially replacing cement with 15% glass powder or zeolite powder does not compromise the mechanical performance and significantly improves the reflectance. Compared with traditional asphalt pavement, the SFP with a glass block content of 40% has excellent high-temperature stability, lower surface temperature, reduced thermal conductivity, and improved thermal resistance. The glass-containing SFP was confirmed to be capable of alleviating the urban heat island effect via simulation.
A review on the heat transfer in asphalt pavements and urban heat island mitigation methods
2022, Construction and Building Materials
Citation Excerpt :
The reflection of this pavement is less than pavements with smoother surfaces [20]. This mechanism positively affects the UHI in urban areas [74]. This type of pavement usually consists of a layer containing fired-clay bricks or concrete, and this pavement in dry areas has higher temperatures than dense asphalt concrete [75].
Heat transfer in the asphalt pavement is significant because it affects asphalt pavement performance and the surrounding environment. This importance is attributed to summertime when the pavement's surface is hot. This hot surface can cause asphalt pavement distresses such as rutting and exacerbate cities' urban heat islands (UHI). Therefore, understanding the heat transfer parameters and UHI mitigation approaches is of great significance. Different thermal parameters, including thermal diffusivity, thermal emissivity, density, heat capacity, thermal conductivity, solar reflectance index, albedo, and experimental and numerical techniques for measuring and enhancing heat transfer in asphalt pavement, are explained in this study. A considerable amount of solar energy is absorbed by asphalt concrete affecting the environment and mechanical properties of asphalt pavements. Hence, there are numerous reasons for using materials altering the thermal conductivity of asphalt pavement, including transferring heat rapidly from the hot surface to the underneath structure, accelerating the snow-melting process, resistance to low-temperature cracking, cooling down the surface of the pavement to mitigate the urban heat island effect and improve rutting resistance. Indeed, developing a cool asphalt pavement is necessary to alleviate the UHI. Thus, higher thermal emissivity, albedo, and specific heat capacities are desirable for cool pavements. However, high thermal diffusivity can decrease heat capacity. Moreover, high conductive materials can reduce the surface temperature during the day, but they are hotter at night. But this has a reverse trend for low conductive materials. Hence, the combination of using high and low conductive materials in different layers can be vital. Regarding UHI mitigation methods, three ways are common, including using the cooling effects of water inside the pavement, increasing the reflectivity of pavements, and altering the thermal conductivity of pavement which are fully investigated in this study. Finally, these solutions' effects can also be evaluated by laboratory and field experiments, which are mentioned.
Evaporative cooling performance estimation of pervious pavement based on evaporation resistance
2022, Building and Environment
Pervious pavement is an efficient cooling strategy to alleviate the urban heat island (UHI) effect because it can retain percolating rainwater for subsequent evaporative cooling. The cooling effect simulation of pervious pavement before implementation is necessary to understand its contribution to the thermal environment. However, it still confronts challenges, due to limited estimation methods of evaporation rate. In this study, we proposed an approach to simulate the evaporation rate of pervious pavements by using the evaporation resistance method (ERM). First, the exponential relationship between evaporative resistance and volumetric water content of two widely used pervious paving materials was regressed by wind tunnel experiments. Second, this ERM was validated by outdoor field experiments of pervious pavements after being integrated into a heat transfer model. Lastly, the best water-sprinkling time was determined based on the model. The results revealed that the evaporation resistance sharply increased when the volume water content of ceramic brick (CB) and pervious concrete (PC) was below 6.5% and 11.8%, respectively. The regressed relationships revealed a high accuracy with all R² above 0.85, and the root mean square error of the surface temperature of the pervious pavement between measurement and simulation demonstrated a high accuracy with CB of 1.31 °C and PC of 1.64 °C. Sprinkling during 07:00 to 11:00 under typical hot-humid climate summer days could gain a win-win effect with sizeable evaporation cooling effects and water-saving.
Effects of pavement texture and colour on Urban Heat Islands: An experimental study in tropical climate
2021, Urban Climate
Citation Excerpt :
The reduction in maximum surface temperatures could have resulted from the tropical geological factors such as soil moisture content of the ground conditions and as the study was conducted at an experimental scale. In addition, when the solar angle is lower with the surface, the surface temperatures are higher, and the albedo becomes higher (Li, 2015). The data collection of the present study was conducted from September (equinox) to December (solstice) period in Colombo, Sri Lanka.
Typical pavement construction materials, such as concrete and cement can significantly increase the Urban Heat Island (UHI) effect in tropical cities. The optimized pavement designs can, however, moderate the temporal intensities of the UHI effect by altering the radiation and heating absorption capacities. This study empirically analyses and attempts to inversely quantify the effect of pavement texture and colour on the characteristic thermal performance of concrete pavers in a tropical climate. Concrete pavers of three common textures (Smooth, Rough, Jagged) and three common colours (Red, Grey, Black) were studied under controlled ambient conditions, considering 27 experimental pavement setups (1 ft. × 1 ft. and three replicates). According to the results, in comparison to Black; Red and Grey coloured pavers showed up to 4.2 °C, and 4.5 °C lower surface temperatures respectively during the peak hours, within each texture. When considering the texture of Grey pavers, the Smooth texture showed up to 2.6 °C lower temperature retention. However, among all pavement types considered, Red Jagged showed the lowest surface temperature record of 42.9 °C which is 0.6 °C cooler than Grey Smooth. Holistically, it can be concluded that, considering both paver colour and texture of concrete, the Red coloured Jagged paver can minimize the pavement contribution to the UHI effect.

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Abstract