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Holistic Innovative Solutions for an Efficient Recycling and Recovery of Valuable Raw Materials from Complex Construction and Demolition Waste

Periodic Reporting for period 3 - HISER (Holistic Innovative Solutions for an Efficient Recycling and Recovery of Valuable Raw Materials from Complex Construction and Demolition Waste)

Reporting period: 2018-02-01 to 2019-01-31

EU28 generates around 500 million tons per year (in weight, a third of the total generated waste) of Construction and Demolition Waste (C&DW), ever more complex due to construction evolution (e.g. polymers, composites). Despite the high recovery potential, current EU average recycling rate is ca. 50%, versus 70% recovery target established by EU for 2020, in line with Europe’s transition towards a circular economy.
An efficient recovery of raw materials from buildings requires both enhanced identification and segregation of materials at demolition/refurbishment works (production of less complex waste streams, thus enabling a more efficient recycling) and new integral recycling approaches.
Moreover, the inclusion of such recycled products in the European Standards and Directives can foster their market acceptance.
In this context, the main goal of HISER has been to develop and demonstrate solutions for a higher recovery of raw materials from this ever more complex C&DW.
One of the most important outcomes of the project is a smart tool (HISER BIM-SD) based on building information modelling. HISER BIM-SD produces a building inventory, enabling engineers to determine the types, qualities, and quantities of building waste materials that will be generated. Compatible with almost any portable device, it is easy to use at any worksite.
Several technologies have been also developed to support sorting, breakdown, and automated quality assessment to produce raw materials with purities between 80-100 % for incorporation into new building products.
HISER has also produced low CO2 cement, cost-effective green concrete, bricks, plasterboards and wood-polymer composites with recovered stony aggregates, ceramic, sand, gypsum, wood and mineral wool.
This combination of preliminary identification, onsite classification, automatic sorting and advanced recycling technologies is making circular economy possible in the construction sector.
The HISER project may have ended but its work and vision continue with important impact on the construction sector and the environment.
HISER project started with the development of solutions for supporting demolition works, traceability of resulting streams, recycling of obtained demolition waste and manufacturing of new building products with high amounts of recycled materials.
Regarding tools for improved demolition/refurbishment works, two solutions were developed:
• The Smart BIM-SD software tool. It includes a module for a guided onsite waste inventory using a tablet on a graphical (BIM based) model of the building, providing automated and reliable calculation of (waste) materials. Another module supports the planning of the demolition project. The tool was integrated with Rhino commercial software and fully demonstrated in the internal case studies and exploited in pilots for some municipalities in Basque Country.
• TRACIMAT, an innovative tracking system, is based on (and monitored by) an external and neutral organisation that will certify the selective demolition process. Both the quality and the trust in the to-be-recycled material receiving a “certificate of selective demolition” will enhance.
For the technological solutions for C&DW recycling, several technologies were developed. Obtaining high-purity concrete aggregates and ceramic aggregates is the objective of the following ones:
• Sensor based sorting equipment is designed to split, in one single stage, pre-processed mixed aggregates into (1) concrete aggregates, (2) ceramic aggregates and (3) others, being the purity of both aggregates above 95%. The prototype was completed during the 2nd RP.
• Electro-fragmentation for the selective release of materials adhered to/embedded in concrete/brick, as short steel reinforcing fibers. Clear exploitation potential has been identified related to steel fiber reinforced concretes recycling.
• Evolved mobile treatment plant of the “C2CA concrete recycling process”, including ADR (Advanced Dry Recovery) and a (Laser-induced breakdown spectroscopy LIBS) quality assessment unit (dealing with 4-12 mm concrete aggregates at 30 tonnes per hour).
Additionally, building products including the aforementioned raw materials were developed:
• Low-embodied energy “HISER cement”, based on “conventional” Ordinary Portland Cement (75%) and recycled waste materials (25%, using concrete fines and float glass).
• Green concretes that incorporate “HISER cement” and selected (concrete) coarse and (concrete and ceramic) fine aggregates, tested and validated during 2nd RP. Also, a study around the input variables (data from the LIBS) and output (resulting concrete compressive strength) quality in the “C2CA concrete recycling process” was completed during 2nd RP.
• Recycled bricks including 10% recycled ceramic waste as replacement of porphyry sand were achieved at the end of the 1st RP. Test samples including crushed bricks of varying fineness, contaminated (gypsum and mortar) and uncontaminated, were analysed during 2nd RP.
Also recycling equipment and recycled products from gypsum waste were developed: (1) a portable (to be taken inside the building) one-operator machine, for clean pre-consumer plasterboard waste (capacity: 600-900 kg/h, prototype is constructed); (2) a mobile (onsite/transfer point) machine, including sorting of other materials stuck to gypsum (capacity ca. 10 t/h, design finished and prototype being assembled). Trials of the new gypsum products including recycled (gypsum/wood) raw material were completed.
Recovery concepts for wood and mineral wool were sketched out. Crushing and refining phases were tested and optimized. Recycled raw wood and wool were utilised in the manufacturing of gypsum plasterboards and extruded composites. Overall 34 formulations of (single and multilayer) composites including recycled wood and wool were extruded to test bars and tested. Virgin and recycled PP and PE were used in experiments.
HISER solutions were demonstrated under 5 representative case studies.
By achieving project objectives, relevant improvements to economy, environment and society are expected.
For instance, unlocking a significant volume of various raw materials through conversion of waste in resources, reducing environmental footprint due to the increase in use of recovered materials or creating green jobs.
Specific impacts are:
- Smart BIM-SD tools and methods for smart quantification and supply chain tracking developed in HISER, together with novel HISER advanced technologies for recycling and recovering diverse materials from C&DW, will contribute to the shifting from low grade recovery to high grade recovery (currently representing about 26 Mt/year in 2014 and aiming to 159 Mt/year by 2025-2030; if asphalt is excluded, 8Mt/year in 2014 will shift to 103 Mt/year by 2030), as well as valorizing emerging flows.
- Around 9 Mt of recycled concrete aggregates are expected to be used in cement and concrete by 2020. The development of more efficient VIS+NIR sensor automated sorting units will enable the use of recycled ceramic aggregates in new bricks, cements and concrete (around 4 Mt55) by 2020. Progress in comminution and refining of C&D wood waste might lead to recovery of up to 0.4 Mt56 of wood fibers for use in particle boards, plasterboard or composites by 2020. Also 0.4 Mt of recovered gypsum is expected to be used in new plasterboards.
Mobile treatment plant for C&D concrete waste: upscaling ADR and inline sensory quality assessment
Laboratory test: Recycled brick samples including recycled masonry aggregates