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REuse and REcycling of CDW materials and structures in energy efficient pREfabricated elements for building REfurbishment and construction

Periodic Reporting for period 3 - RE4 (REuse and REcycling of CDW materials and structures in energy efficient pREfabricated elements for building REfurbishment and construction)

Reporting period: 2019-03-01 to 2020-02-29

Resource efficiency and raw materials are two of the main societal challenges identified by the Europe 2020 strategy and a proper Construction and Demolition Waste (CDW) management is a priority target. A minimum target of 70% by weight of non-hazardous CDW for reuse, recycling and other material recovery must be achieved by 2020
RE4 aims at contributing to reach this target providing innovative technologies and reliable strategies for the design and manufacturing of structural and non-structural pre-fabricated elements with high degree (up to 100%) of recycled materials and reused structures from partial or total demolition of buildings.
This involved the development of several intermediate but self-standing industrial results, like a) the RE4 innovative CDW sorting system based on automated robotics equipped with advanced sensors to increase the quality of CDW-derived material with the highest technical and economic interest (i.e. ceramics, wood and timber, glass, clay, plastic and virgin aggregates for concrete), b) a number of RE4 prefabricated building components and elements (including connections) based on CDW-derived materials and structures, c) the related production processes and equipment, and d) a new RE4 BIM compatible ICT tool to manage materials flows.
The RE4 prefabricated building components are suitable for both new construction and building refurbishment and they were assembled into a RE4-prefabricated energy-efficient building concept designed for an easy installation and dismantling, as addressing the relevant regulations and standards. RE4 results have been produced in an industrial environment, considering their perspective issues for the market uptake.
RE4 project has achieved several self-standing and exploitable results built upon four main technical and non-technical pillars.

1. The first technical pillar refers to the maximization of the amount of recycled valuable materials from CDW for high-value applications. RE4 developed an advanced robotic system for sorting, based on weight criteria, able to provide high-quality CDW-derived mineral aggregates and to sort materials with high economic value by type (ceramics, glass, plastic, and timber) currently unexploited. Moreover, RE4 has defined new quality classes for CDW-derived aggregates and identified optimal recycling strategies for each mineral and lightweight CDW fractions, with potential applications and suggested replacement rates depending on the CDW quality and variability. The RE4 proposal for new CDW quality classes has been sent to standardization committees with the aim of supporting the development of standards in the field. Finally, the CDW recycling potential has been verified with the development, testing and up-scaling from the laboratory to the prefabrication scale of RE4 materials and prefabricated elements incorporating high ratios of CDW (8 new materials – normal and lightweight concretes with Ordinary Portland Cement or Alkali Activated Binders, with consistency of self-compacting, vibrated, and semi-dry concretes and with an average virgin material replacement in the final product in the range of 50-85%, earthen plaster and mortar and rammed earth with an average virgin replacement in the final product in the range of 67-87%; 4 new components – blocks, tiles, timber components, insulating panels – and 4 new prefabricated elements – concrete and timber façade panels, load-bearing concrete elements, internal partition walls with an average virgin material replacement in the final product in the range of 50-85%).

2. The second pillar is about building components reuse, by developing new sustainable strategies for the disassembly and reuse of concrete and timber structures and building components at the end of their service life. RE4 has developed innovative design concepts for a fully prefabricated, easy dismountable RE4 building, with up to 90% of reusable structures. RE4 building elements have been designed for different climatic as well as structural requirements of different geographic zones across Europe (UK, Spain, and Italy) and outside EU (Taiwan).

3. The third pillar focuses on CDW management improvement by digitalisation, proposing a BIM-compatible Decision Support System (DSS) able to support owners and construction/demolition companies by providing an estimation of the types and quantities of CDW that will be generated during construction/demolition, with possible utilization options and related logistic references.

4. The fourth pillar is related to increase the acceptance of secondary raw materials by end-users. To this aim, RE4 provided a large study on CDW management across Europe, defined specific lessons learned and recommendations. Moreover, RE4 is able to increase the acceptance of CDW-based products by means of performance assessment, certification and standardisation strategies, Life-cycle analyses (including s-LCA), HSE analyses, and training activities.

All the above mentioned solutions have been integrated and validated in 2 two-storey new construction demo-buildings (in Spain and in UK). The demonstration of the strategy for disassembly and reuse of materials and structures from dismantled buildings has taken place in ACCIONA demo building. The RE4 solutions for refurbishment have been applied to suitable existing buildings (Italy and Taiwan). Seismic performances of RE4 solutions have been also verified through shaking table testing.

RE4 showcased the obtained results with a massive dissemination and communication activities plan (by means of more than 100 dissemination and training events and actions).
Finally, in order to push the RE4 solutions to go to the market, business models and exploitation plans related to the RE4 prefabricated building and RE4 prefabricated components as well as to the RE4 sorting system are performed.
RE4 solutions will be of direct benefit to project partners, and indirectly to the external CDW value-chain players and in general to EU citizens. Partners and industrial players will take a competitive advantage in leading, as frontrunners, the transition from a linear towards a circular economy in the Construction sector. Contractors can make demolition activities more economically viable and ensure the quality of secondary raw materials coming from the demolition. Precast producers can standardise the production for increasing efficiency of the processes. Designers can fulfil requirements for green building scoring systems. Moreover, the RE4 solutions can create important spill-overs for the entire society with new and high-skilled job opportunities and businesses in the green economy.
In terms of positive effects on the environment, minimizing the environmental impact of the Construction sector in terms of CO2 reduction and energy savings and raw materials consumption the RE4 results are: a) CO2 savings more than 40% on average, b) energy savings more than 45% on average and c) share of recycled materials in final product of more than 50% on average.
Moreover, RE4 solutions resulted to be cheaper than conventional solutions of more than 15%.
The RE4 Project has demonstrated how CDW-derived materials and structures can be effectively reintroduced in the production cycles and that technically, a fully prefabricated, 100% reusable building is now a reality.
RE4 Brochure 2nd release (page 1)
RE4 Demo Building (Toomebridge, UK)
RE4 Demo Building (Madrid, Spain)
RE4 project logo
RE4 Technical flyer (page1)
RE4 EGA House (Taiwan)
RE4 Technical flyer (page2)
RE4 Brochure 2nd release (page 2)
RE4 Demo Building (Benevento, Italy)