2020 - 2022: An interregional project to combat global warming in urban areas.

For decades, meteorologists and climatologists around the world have been observing the effects of global warming on meteorological phenomena: more precipitation or more drought, increased heat waves, increase and aggravation of extreme climatic phenomena: cyclones, storms, hurricanes...

It is therefore necessary to adapt. This requires the protection of goods and people (heat wave plan, flooding plan, fight against fuel poverty...), the maintenance and preservation of natural heritage (forests, dunes, dykes...) or the development of urban space (urban layout and buildings; fountains and cooling points, green spaces and vegetation...). Cities are particularly concerned by global warming because of the density of activities and populations.

Paris and the Plan Climat Energie Territorial (PCET)

Paris is the French city most affected by the Urban Heat Island (UHI) phenomenon. This phenomenon results in the creation of a heat bubble over the city, which is subject to high temperatures during the day. This bubble is not present in rural areas due to the abundance of vegetation and permeable soils that consume/absorb the solar energy received during the day instead of being, as in the city, accumulated and stored in the materials of buildings and impermeable surfaces.
The temperature differences between city and rural areas in Paris are about 2.5°C but can reach 10°C in summer. However, within the same urban area, there are micro-zones of heat and "cool islands". These variations are due to the morphology of the city, the radiative and thermal properties of the materials and the land-use pattern at the neighbourhood level.

FRESH-ECOPAVERS or draining paving stones capable of restoring coolness in the event of strong heat

In this context, the FRESH-ECOPAVERS project was born between Normandy and the Seine Valley. Indeed, Normandy and more particularly the ESITC Caen laboratory developed in 2015 a shell concrete paver whose formulation gives it a major draining character. This paver, was initially designed to meet a local demand for shell recycling, available in large quantities on the coast. In this context, the ESITC Caen laboratory positioned itself as a player in the circular economy by replacing gravel (an exhaustible resource) with shell waste (in abundance). The shell paving stone was born and its characteristics were studied. We have found that the presence of
shells in the concrete gave the paving stone an important porosity and thus a strong draining character.
This paver is now licensed and sold throughout the city. However, if it is capable of draining water quickly into the ground, the opposite effect is also possible. This paving stone would thus have the property of restoring the coolness of the ground in hot weather conditions. Thus, for functions such as parking, bicycle paths, waste treatment areas... an area made of shell paving stones would make it possible to artificially create islands of coolness, which are so disparate on the scale of a city like Paris.
The aim of the FRESH-ECOPAVERS project is to carry out pilot operations in Normandy and eventually in the Ile de France region, and to instrument them in order to study and optimize this phenomenon of cool islands.

Partners

The FRESH-ECOPAVERS project is a 960,000 euros project co-financed by ADEME, the Normandy Region and the Ile-de-France Region, bringing together 4 partners: BUILDERS Ecole d'Ingénieurs (project coordinator), ESITC Paris, the Agence Parisienne du Climat and the city of Alençon