COOL PAVEMENTS FOR URBAN HEAT ISLAND EFFECT MITIGATION (COOLUM) - Papers

Using bio-oils for improving environmental performance of an advanced resinous binder for pavement applications with heat and noise island mitigation potential

IoannisKousisaClaudiaFabianiabLucaErcolanoniaAnna LauraPiselloab

 

Abstract

Urbanization and actions are responsible for overheated cities compared to the adjacent rural settings, a phenomenon known as Urban Heat Island (UHI). Additionally, conventional urban materials contribute towards the aggravation of urban noise pollution, a phenomenon that may be described as Urban Noise Island (UNI). Numerous solutions have been proposed through the implementation of novel, more sustainable, or natural materials in the pavement infrastructure. To that end, this study bridges the gap between UHI and UNI mitigation strategies, simultaneously ensuring low environmental impact. Therefore, a resin-based pavement binder was investigated through multiphysics analysis, together with four innovative binders made with waste bio-oils. Thermal, optical, acoustical and Life Cycle Assessment analysis were carried out for gauging the UHI/UNI mitigation potential of binders and their environmental impact. Results showed that the innovative binders preserved good physical properties: all binders have solar reflectance higher than 50% within 750–1600 nm range and sound absorption coefficient higher than 0.8 within 600–800 Hz. Additionally, bio-oils decreased the environmental impact of the binder up to 37.46mPt, and 8.33% in the ReCiPe, and Intergovernmental Panel on Climate Change analysis, respectively. Therefore, the exploitation of bio-oils in the pavement market can be considered as promising green solution for mitigating both UHI and UNI.

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Phosphorescent-based pavements for counteracting urban overheating – A proof of concept

IoannisKousisaClaudiaFabianiabLauraGobbiaAnna LauraPiselloab

 

Abstract

The built environment is particularly sensitive to elevated temperatures across urban areas. Furthermore, engineered materials usually amplify surface overheating, exacerbating urban heat island and cooling energy needs. In the last decades, the scientific community introduced a new class of materials, i.e. cool materials, in the attempt of mitigating these phenomena. In this context, this work investigates the hygrothermal and radiative potential of phosphorescent-based paving solutions and benchmarks their performance against commercially available cool concrete. To this end, an extensive outdoor monitoring campaign was carried out in terms of surface/air temperature, relative humidity, reflected solar radiation and wind speed/direction during summer 2019. Phosphorescent-based fields were found to maintain lower superficial temperature than the reference during the hottest hours of the day, by up to 0.9C and 3.3 C in terms of average and absolute values, respectively. Even though other cooling techniques have been found to have higher cooling effect, the outcomes of this study, reveal for a first time, (i) the promising thermal behavior of phosphorescent-based pavements, as well as (ii) their potential for developing advanced cool materials equipped with both radiation reflection and re-emission mechanisms.

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For the mitigation of urban heat island and urban noise island: two simultaneous sides of urban discomfort

Ioannis Kousis1 and Anna Laura Pisello2

Abstract

Urban environment well-being has become a crucial public issue to face, given the huge concentration of population and climate change-related hazards at a city scale. In this view, Urban Heat Island (UHI) is now very wellacknowledged to be able to produce a serious threat to populations around the world and compromise human well-being due to aggressive overheating, exacerbated by anthropogenic actions. The same anthropogenic actions are also responsible for other discomfort causes such as noise pollution, which has also been demonstrated to heavily impact societal life and health conditions in urban systems. Both these phenomena typically co-exist in terms of space and time coincidence, and they both may be mitigated by means of smart adaptive and multifunctional surfaces including urban pavements and building envelopes. This review bridges the gap between only-thermophysical analyses about UHI mitigation and only-acoustics analysis of urban noise pollution, here dened as Urban Noise Island (UNI). To this aim, the key physics background of mitigation techniques is presented and the most innovative and promising solutions for counteracting UHI and UNI are described, with the nal purpose to foster research and innovation toward more livable cities through a multiphysics and holistic view.

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