Landscape adaptation of the surroundings of the former Central University Hospital of Asturias

The available scientific evidence demonstrates with a high level of confidence that the climate of Asturias is experiencing an accelerated change, driven by the high concentration of greenhouse gases in the atmosphere due to human activity, whose main features are a widespread increase in temperatures, with warmer and drier summers, and an increase in the likelihood of extreme weather events. In urban environments, the most significant foreseeable impacts are the worsening of the "heat island" effect, the increase in air pollution due to thermal inversion, and the decrease in thermal comfort in public spaces, which translate into direct risks to the health and well-being of the population, as well as dysfunctions in water supply and sanitation infrastructure.

It is therefore necessary to design measures that improve the adaptability of our cities and towns to the risks of climate change. The main strategies to advance the improvement of urban resilience are: adapted management of water resources, renaturalization and redesign of public spaces, and circularity in the cycles of materials and other natural resources.

The construction sector uses —in the case of industrialized countries— about 40% of natural resources, consumes approximately 70% of electricity and 12% of drinking water, while producing between 45% and 60% of the total waste deposited in landfills. Consequently, the volume of emissions for the production of various materials, given their high energy consumption, is also very significant.

At the same time, the end of the life cycle of these materials, that is, their transformation into construction and demolition waste (CDW), causes multiple environmental impacts when disposed of in the environment, such as "water pollution, poor urban air quality, or the degradation of natural systems" (Cuchí and Sagrera, 2007, p. 59). These impacts undoubtedly highlight the inherent unsustainability of the continuity of the current extractive and productive model, which compromises the capacity of terrestrial ecosystems to generate new natural resources through the overexploitation of these for the uses demanded by the socioeconomic rhythms of our times. Thus, considering the high consumption and emission costs associated with the production of various materials, along with the environmental impact resulting from their subsequent disposal— in the form of waste— into the natural environment, the extension of their life cycle emerges as an imperative necessity for adapting to future climate change scenarios in the construction sector.

This extension of the material lifecycle necessarily involves a paradigm shift: what is now considered waste becomes an opportunity and is regarded as a resource. This reconsideration aims to achieve a closed loop of the various materials involved in construction processes through reuse and recycling. Thus, the set of stages in the cycle of materials and resources for construction must adapt to this new approach, starting from a design that allows for subsequent deconstruction, separation, and reuse of materials within a territorial scope as close as possible, thereby ensuring the circularity and sustainability of construction processes.

The present study aims to transcend the traditional use of demolition materials and reapply them in the improvement of road infrastructures, the design of sustainable urban drainage systems (SUDS), urban greening, and the increase of biological diversity, thus contributing to the closure of the construction cycle. At the same time, it will contribute to reducing the economic and environmental costs associated with transportation—mainly derived from fossil fuel consumption and its GHG emissions—due to the proximity of the agents involved in the reuse process.

The document includes guidelines, recommendations, and design criteria for the application of the valorization of C&D waste in actions for the creation or improvement— in terms of resilience to climate change— of public spaces.
In the complete case of the surroundings of HUCA, in the El Cristo neighborhood of Oviedo, the interim landscape proposal (pending the Special Plan) aims to preserve existing values and transform the waste generated by the demolition into a new topography that collects material and multiplies the accessibility and habitability of the area.
Just as the building is considered a storage of materials, the landscape adaptation of the urbanization allows for the creation of a temporary storage of waste.

This warehouse can contain at least 3 types of waste:

- Crushed concrete aggregates in new hills. They will be used in the future, when the urbanization of the special plan for fillings, embankments, backfilling of building retaining walls, among others, is carried out. They will preferably be located within the "footprint" of the General Hospital and its hills.

- Ceramic stones and factory-made structures for basement fill, construction of slopes where there were previously retaining walls, and new elevations to be reused in the future also in urbanization, drainage, pavement subbases, etc. They are preferably located in the expansion of the Truébano Park,

- Concrete stones and masonry in the form of compost recysoil for the topsoil layer of the new mounds and hills.

No specific urbanization work from the Special Plan is being carried out, but neither is anything that could condition it. It is about leaving the "stockpiled" material on the plot in the form of new green topographies.

- The soils. The use of substrates with properties similar to black peat is recommended, with a granulometric distribution that favors aeration but not water retention, and with low wettability. The addition of fine aggregates considerably improves water retention and wettability, achieving values similar to those of agricultural soil. The plantations should be defined according to the slope of the land, the use, and the maintenance needs.

However, general guidelines are defined, especially regarding slopes, favoring their stability, and regarding flower meadows, proposing gardening that respects the natural environment, is more ecological, and adapted to the surroundings.

- The treatment of the paths. Small adjustments will be made to the existing paths and new ones. For these, the use of recycled concrete aggregates, partition walls, tiles, and roofing tiles is recommended.

- The placement of excessive street furniture will be avoided, limiting it to essential lighting elements, benches, and trash bins to achieve the appropriate conditions of safety and usability in the area.

In any case, the reuse of existing elements (given the temporary nature of the proposal) and/or those from revaluation processes will be prioritized.