Deconstructable Concrete Structures Made of Recycled Aggregates from Construction & Demolition Waste: The Experience of the DeConStRAtion Project

The construction sector is one of the most energy-intensive and raw-material demanding human activities and hence contributes a significant share of greenhouse gas emissions. Therefore, making the construction sector greener is one of the main challenges for policy makers, private companies and the scientific community. To this aim, one of the most promising actions is based on recycling Construction and Demolition Waste (CDW) and converting them into secondary raw materials for the construction sector itself. On the other hand, the reduction of the environmental impact can be further amplified through the optimization of the production, assembly and deconstruction/reuse procedures as well as through the maximization of the service life. In this context, the present paper presents the main results of a research project aimed at exploring the possibility to define a concept for deconstructable buildings made by prefabricated modular Recycled Aggregate Concrete (RAC) elements. The concept is based on assembling duly sized and designed prefabricated blocks by means of a prestressing system based on an innovative memory®-steel technique. The target building typology is that of highly modular structures, which generally demand high construction speed and the possibility of reconversion of internal spaces. Several issues are targeted to achieve within the project activities: proper design of mixtures leading to durable RAC members, the most appropriate structural configuration, and assembling technique are considered for achieving deconstruction capabilities. A proof of concept is then designed, produced and tested.