Innovative pavement solution for the mitigation of the urban heat island effect

PROJECT DESCRIPTION

BACKGROUND

The development of urban areas, which replaces land and vegetation with buildings, roads and other infrastructure, leads to the formation of urban heat islands (UHI), whereby urban regions experience warmer temperatures than their rural surroundings. The annual mean air temperature of a city with one million people or more can be 1-3°C warmer than its outlying rural areas, but the temperature difference can be as much as 12°C. Even smaller cities and towns produce UHIs, though the effect is less pronounced in smaller urban areas. The impact of climate change could be exacerbated by the UHI effect in urban areas.

This increased attention to heat-related environment and health issues has helped to advance the development of UHI reduction strategies, mainly trees and vegetation, green roofs and cool roofs. Interest in cool pavements has also risen recently: different factors influence UHI development, such as the solar reflectance and thermal emittance of the material used, along with pavement temperatures that is determined by its permeability, convection, thermal conductivity, heat capacity and thickness. Cool pavements have been developed all around the world, though more research and demonstrative projects are needed to help communities to better understand the interactions between pavements and urban climate.

Implementation of the proposed cool pavement technology, however, has not previously been attempted. Much cool pavement development has been carried out on squares or plain areas (e.g. parking lots and sports courts), but not on city roads and not monitored closely.

OBJECTIVES

The LIFE HEATLAND project aims to demonstrate the mitigation of the UHI effect by using an innovative construction material for road surfaces – cool pavements using a mixture of lime aggregated, transparent synthetic binder and titanium oxide and iron oxides pigments. An innovative pavement will be installed along with four metering towers fitted with diverse sensors (e.g. a pavement surface temperature sensor, three air temperature sensors, an ozone meter and a lux meter) in the city of Murcia. The main objectives of the project are to:

Demonstrate the effectiveness of the technology to mitigate the UHI effect and to reduce the local temperature;

Transfer knowledge generated throughout the project to foster replication in other European cities;

Install innovative pavement in other urban areas, assisted by the project's beneficiaries, or to sign agreements for replication after the end of the project;

Assess the effect of the new pavement on reducing local energy consumption associated with air conditioning, refrigeration devices and street lighting, along with its contribution to reducing noise and air pollution;

Validate the socio-economic feasibility of the proposed pavement solution;

Develop a mathematical model to predict the effectiveness of the technology in different urban areas;

Apply the mathematical model in several European cities to evaluate the replicability potential of the technology in the EU; and

Develop dissemination materials and activities, such as reports, guides, a website, seminars and training courses.

The results of the project will help define a new standard for urban pavements that are resilient to the climate change effects. The project is in line with Action VII of the EU strategy on adaptation to climate change by ensuring more resilient infrastructure. The Commission will launch a mandate for European standardisation organisations to start mapping industry-relevant standards in the area of energy, transport and buildings and to identify standards that need to be revised to achieve better inclusion of adaptation considerations.

Expected results:

24.000 m2 of cool pavement installed (with a solar reflectance that is expected to be increased from 0.05 with a conventional asphalts to 0.46 with the new technology);

Four metering towers installed with data acquisition systems;

A quantitative and qualitative demonstration of the effectiveness of the innovative pavement, with data collected 24 hours a day over two years on pavement surface temperature, air temperature (at heights of 3.5 m and 10 m), moisture, wind speed, solar irradiance, air ozone, illumination level and noise;

Air temperature decrease of 1.5°C and surface pavement temperature decrease of 10°C;

Energy savings of 7% for refrigeration devices and 5% for street lighting;

A mathematical model to predict the effect of the innovative pavement implementation in other urban areas tested in at least four cities;

Quantitative demonstration of the economic feasibility of the new technology;

At least five workshops organised, with the participation of 25 entities, and at least 30 technicians, engineers or architects participating in the three training courses; and

At least 100 municipalities, 30 construction and pavement companies and 20 professional associations directly contacted, and at least 100 entities participating in two conferences.