Closing the Loop of Autoclaved Aerated Concrete (AAC) Recycling Oliver Kreft Xella Technology- und Forschungsgesellschaft mbH Brück, Germany CESB 16 Central Europe towards Sustainable Building 2016 June 22-24, 2016 Prague, Czech Republic

SILKAYTONGHEBELFERMACELL FELS Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, Introduction Autoclaved Aerated Concrete (AAC) Waste statistics in Germany Recycling and deposition of AAC in Germany Drivers for change in waste management Recycling of Autoclaved Aerated Concrete (AAC) Methodology Results and discussion Summary and Outlook Agenda

SILKAYTONGHEBELFERMACELL FELS 3 Introduction Autoclaved Aerated Concrete Roof/Ceiling Exterior wall load bearing/non-load bearing Interior wall non-load bearing Interior wall load bearing YTONG PLANBLÖCKE ® W YTONG Stürze W, tragend YTONG U-Steine und U-Schalen YTONG Dachplatten W YTONG Deckenplatten W YTONG Treppe YTONG Jumbo ® W im Doppelpack YTONG Jumbo ® W Planelemente YTONG System-Wandelemente W YTONG Jumbo ® W im Doppelpack YTONG Trennwandelemente YTONG Planbauplatten GF YTONG Planbauplatten YTONG Stürze, nicht tragend YTONG Stürze W, tragend YTONG PLANBLÖCKE ® W YTONG Jumbo ® W Planelemente Areas of application Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016

SILKAYTONGHEBELFERMACELL FELS Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · April 25, The Production Process of AAC Introduction

SILKAYTONGHEBELFERMACELL FELS Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, Introduction Autoclaved Aerated Concrete (AAC) Waste statistics in Germany Recycling and deposition of AAC in Germany Drivers for change in waste management Recycling of Autoclaved Aerated Concrete (AAC) Methodology Results and discussion Summary and Outlook Agenda

SILKAYTONGHEBELFERMACELL FELS EU Landfill Directive EU Waste Framework Directive EU target 2020: "minimum of 70%" C&D waste (by weight) must be prepared for reusing, recycling or backfilling Recycling rates differ widely across EU member states (e.g., DE, NL at ~90% ; CZ, FR < ~40%) In countries with recycling rates > 70% today, impact of new regulation thus very limited EU Landfill Directive established to reduce overall landfill volumes to ~35% of today's volumes To mitigate product-specific recycling concerns, voluntary taking back agreement discussed in BM industry AAC with structural disadvantage (vs. e.g., Clay) due to unfavorable land-filling classification (level 1 = hazardous waste) 6 Drivers for Change in Waste Mgmt Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016

SILKAYTONGHEBELFERMACELL FELS 7 Annual Mass Flux of Construction Materials in Germany 2013 Total mineral waste in 2013 = million tons Building debris, unsorted (8.2 %) Soil, rocks, spoil (56.6 %) Autoclaved Aerated Concrete (AAC) waste (0.5 %) Gypsum based construction waste (0.2 %) Concrete, bricks, tiles, ceramics (25.6 %) Road construction waste (9.0 %) Source: Statistisches Bundesamt, Germany, Bauhaus Universität Weimar, Lehrstuhl für Aufbereitung von Baustoffen und Wiederverwertung, Introduction Reutilization of waste from road constructions and building debris (ca. 90 %) 37.2 Mio t Recycling (Road construction, civil and underground engineering) 19.9 Mio t Landfills, mining waste consolidation 0.8 Mio t Concrete production 8.7 Mio t Other (unspecified) Reutilization of waste from road constructions and building debris (ca. 90 %) 37.2 Mio t Recycling (Road construction, civil and underground engineering) 19.9 Mio t Landfills, mining waste consolidation 0.8 Mio t Concrete production 8.7 Mio t Other (unspecified) Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016

SILKAYTONGHEBELFERMACELL FELS 8 Annual Mass Flux of Construction Materials in Germany 2013 Total mineral waste in 2013 = million tons Building debris, unsorted (8.2 %) Soil, rocks, spoil (56.6 %) Autoclaved Aerated Concrete (AAC) waste (0.5 %) Gypsum based construction waste (0.2 %) Concrete, bricks, tiles, ceramics (25.6 %) Road construction waste (9.0 %) Source: Statistisches Bundesamt, Germany, Bauhaus Universität Weimar, Lehrstuhl für Aufbereitung von Baustoffen und Wiederverwertung, Introduction Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016

SILKAYTONGHEBELFERMACELL FELS 9 Utilization and Recycling of AAC in Germany, 2009 Source: Bauhaus Universität Weimar, Lehrstuhl für Aufbereitung von Baustoffen und Wiederverwertung, 2010 / German Autoclaved Aerated Concrete Association, Introduction Data collected from 109 German waste management companies in 2009 (Random examination) Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016 Costs for acceptance of AAC-waste range from 3 to 160 €/t (Average = 58 €/t)

SILKAYTONGHEBELFERMACELL FELS EU Landfill Directive EU Waste Framework Directive EU target 2020: "minimum of 70%" C&D waste (by weight) must be prepared for reusing, recycling or backfilling Recycling rates differ widely across EU member states (e.g., DE, NL at ~90% ; CZ, FR < ~40%) In countries with recycling rates > 70% today, impact of new regulation thus very limited EU Landfill Directive established to reduce overall landfill volumes to ~35% of today's volumes To mitigate product-specific recycling concerns, voluntary taking back agreement discussed in BM industry Today: Efficient and economically sound concept for recycling of current levels of C&D waste exists (main application: sold as cat litter ('Katzenstreu' )) Long-run: Potential challenge to cope w/ large amounts of demolition waste due to land-filling classification AAC with structural disadvantage (vs. e.g., Clay) due to unfavorable land-filling classification (level 1 = hazardous waste) But: Varietal pure separation of C&D waste key for reusability or recyclability required ! 10 Drivers for Change in Waste Mgmt Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016

SILKAYTONGHEBELFERMACELL FELS Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, Introduction Autoclaved Aerated Concrete (AAC) Waste statistics in Germany Recycling and deposition of AAC in Germany Drivers for change in waste management Recycling of Autoclaved Aerated Concrete (AAC) Methodology Results and discussion Summary and Outlook Agenda

SILKAYTONGHEBELFERMACELL FELS 12 Recycling of AAC Processing of Autoclaved Aerated Concrete (AAC) Deposition Waste Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016

SILKAYTONGHEBELFERMACELL FELS 13 Recycling of AAC Processing of Autoclaved Aerated Concrete (AAC) Deposition Waste Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016 Result: Too many associated materials that involve technological risks.

SILKAYTONGHEBELFERMACELL FELS 14 Unprocessed AAC-returns (examples) from waste management companies in Köln and Recklinghausen, Germany (2011). Recycling of AAC AAC-RC Material from Waste Management Companies (Germany) Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016 Result: Too many associated materials that impair the visual appearance.

SILKAYTONGHEBELFERMACELL FELS Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, Pilot study with Otto Dörner Anlieferung Altporenbeton an das Werk Wedel Altporenbeton vor der Zerkleinerung im Werksbrecher Splitt aus Alt-Porenbeton Otto Dörner Im Vergleich: Frischer PB-Splitt, Werk Wedel Recycling of AAC  Allocation of sorted,salvaged AAC  Processing and mineralogical/chemical analyses by Xella  Granulation of salvaged AAC in the Ytong factory Wedel. Test production of quality class P4-0,55 Autoclaved Aerated Concrete with 10 M% RC-AAC-split.

SILKAYTONGHEBELFERMACELL FELS 16 Prüfpunktfrischer Splitt Wedel (TP01) Splitt aus Alt-BP/Otto Dörner (TP02) SiO 2 51,28 M.-%58,76 M.-% Al 2 O 3 2,41 M.-%2,54 M.-% Fe 2 O 3 0,98 M.-%1,02 M.-% MnO< 0,05 M.-% MgO0,41 M.-%0,34 M.-% CaO25,19 M.-%24,74 M.-% Na 2 O< 0,05 M.-% K2OK2O0,64 M.-%0,61 M.-% CO 2 5,42 M.-%1,99 M.-% SO 3 5,72 M.-%2,30 M.-% Moisture (105 °C)17,78 M.-%23,66 M.-% K + (aqu.)14 mg/l0 mg/l Cl - (aqu.)25 mg/l20 mg/l [SO 4 ] mg/l1.655 mg/l Na + (Photometer)23 mg/l18 mg/l XRF of the DEV S4- Eluate XRF of the DEV S4- Eluate RFA-Analysis C-S- Ana- lysis Prüfpunktfrischer Splitt Wedel (TP01) Splitt aus Alt-BP/Otto Dörner (TP02) Amorphous21,04 M.-%45,03 M.-% Tobermorite26,70 M.-%17,60 M.-% Quartz28,48 M.-%35,15 M.-% Calcite7,70 M.-%n. b. Vaterite4,84 M.-%n. b. Gypsum6,58 M.-%n. b. Mikrokline2,29 M.-%2,24 M.-% Plag. Albite0,96 M.-%n. b. XRF-Rietveld-Analysis  Chemical analysis  Mineralogical analysis From a chemical/mineralogical point of view, split from the test production from was equivalent to split from freshly produced AAC Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016 Recycling of AAC

SILKAYTONGHEBELFERMACELL FELS 17 Example: Class P AAC with 10, 15, 20 w-% AAC-RC-Split Impact of RC-AAC on the Product Quality of Freshly Produced AAC Result: Depending on the quality of the RC-material admixes of up to 20 w-% are tolerable for the production of i. e. class P AAC. Result: Depending on the quality of the RC-material admixes of up to 20 w-% are tolerable for the production of i. e. class P AAC. Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016 Recycling of AAC

SILKAYTONGHEBELFERMACELL FELS 18 What makes the material from Otto Dörner that special? State-of-the-art sorting technology at multiple steps! Relevant sorting steps for the preparation of pure ACC are shown in grey Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016 Recycling of AAC

SILKAYTONGHEBELFERMACELL FELS Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, Introduction Autoclaved Aerated Concrete (AAC) Waste statistics in Germany Recycling and deposition of AAC in Germany Drivers for change in waste management Recycling of Autoclaved Aerated Concrete (AAC) Methodology Results and discussion Summary and Outlook Agenda

SILKAYTONGHEBELFERMACELL FELS Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, (1)Controlled deconstruction instead of demolition of buildings: Our aim is to achieve highest possible sorting accuracy together with economically effective processing technologies (2)Improved Recycling technologies: Existing technologies must be further developed from a technical and economical point of view (3)Reutilization into the ongoing production of construction materials: Collection of technical and economical data. Deduction of quality requirements for the input-material together with recommendations for specific product lines. Legal/political solutions for an easier handling of secondary raw material (removal of the “waste-status“ of demolition waste). Three Columns of Xella‘s Holistic Recycling Concept Summary and Outlook

SILKAYTONGHEBELFERMACELL FELS 21 Utilization of natural resources Production of AAC Construction and use phase Demolition Deposition of construction materials after their use phase Carbon footprint of AAC largely determined by embodied energies of raw materials (quick lime and cement) Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016 Summary and Outlook Current life cycle of Autoclaved Aerated Concrete...

SILKAYTONGHEBELFERMACELL FELS 22 Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016 Summary and Outlook... and the holistic recycling-loop in view of Europe 2020

SILKAYTONGHEBELFERMACELL FELS 23 Thank you! Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016

SILKAYTONGHEBELFERMACELL FELS 24 Possible Contamitants of AAC and Calcium Silicate Units and their Consequences for High Quality Recycling Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, 2016 Recycling of AAC

SILKAYTONGHEBELFERMACELL FELS 25 Shown by using the example of AAC: Used AAC (1) is collected and sorted (2) by recycling facility operators. The sorted material is crushed, sieved (3) and subjected to laboratory tests (4). Approved batches of AAC granules are used as substitutes for primary raw material in the ongoing production of AAC (5). Xella‘s Intended Recycling Circuit for Ytong, Silka and Multipor Holistic Recycling-loop in View of Europe 2020

SILKAYTONGHEBELFERMACELL FELS Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · April 25, Production waste or sorted AAC- remains from construction sites are either (1)returned into the ongoing production of AAC (as substitute for natural sand) or (2)processed towards granulates (i.e. cat litter, oil binder). Xella‘s present recycling-loop for AAC The Production Process of AAC Xella‘s Present Recycling Service

SILKAYTONGHEBELFERMACELL FELS 27 Such big bags are supplied to the customer together with encoded fasteners and return vouchers. The customer fills the big bags with sorted remains of AAC and/or Multipor and returns it to Xella. Except for transport, no costs incur for the customer. Our Simple Way to Return AAC-remains from the Construction Site to the Factory Xella‘s Present Recycling Service

SILKAYTONGHEBELFERMACELL FELS 28 Landfill capacities for waste class I significantly decrease Requirement to develop strategies on the recycling of AAC-waste Existing Landfill-sites in the Deposition Phase (NRW/Germany) Source: Landesamt für Natur, Umwelt und Verbraucherschutz (LANUV), Germany. Class I = mandatory for AAC Introduction

SILKAYTONGHEBELFERMACELL FELS Summary and Outlook Dr. Oliver Kreft · Xella Technologie- und Forschungsgesellschaft mbH · June 22, Recycling of AAC ►AAC monofractions from controlled demolition or waste sorting plants ►In order to prevent any ecological or human- toxicological hazards, Xella deduced limit-values for trace-elements. ►In our own requirement profile we define conditions for receipt, storage, processing, execution of analyses and limit values. ►Processing (grinding) and reutilization into the ongoing production of AAC

SILKAYTONGHEBELFERMACELL FELS 30 Recycling of AAC Reutilization of AAC demolition waste as an aggregate into the production of fresh AAC

SILKAYTONGHEBELFERMACELL FELS 31 Focus today Waste mgmt: Xella with superior solution today Increasing regulation 1 : Waste mgmt most likely producers' liability in the future 1. See, e.g, EU Waste Framework Directive 2008/98/EC Source: Xella Technology- und Forschungsgesellschaft mbH: "Recycling of Construction (April 2015); BCG analysis AAC blocksClay blocks Construction & demolition waste Reusing (both AAC and clay waste can – under certain conditions (e.g., purity) – be reused for production) Recycling (AAC waste easily recyclable for different uses, e.g., 'Katzenstreu') Land-filling (due to land-filling classification in DE ("level 1"), AAC 4-5x more expensive) Back-filling (AAC not suitable as aggregate for, e.g., road construction) Today's recycling solution superior to Clay (volumes fully absorbable) – however, solutions to be developed for potentially larger volumes mid- to long-term Focus today Waste products actually sold today ! Back-filling usually free of charge

SILKAYTONGHEBELFERMACELL FELS 32 European Waste Framework Directive 2008/98/EC New or enhanced regulations: Waste prevention Waste hierarchy Extended waste producer responsibility Extended product/producer responsibility (acceptance of returned waste) Inspections Enforcement sanctions Long-term goal of the EU is to become a recycling society, that seeks to avoid waste and which uses waste as a resource. By 2020, recycling, recovery & preparation for reuse must be achieved for 70 % of discarded non-hazardous construction & demolition waste. Introduction