Building material recycling

from Wikipedia, the free encyclopedia
Modern mobile building material processing plant.
Wall of an earthship , built among other things from old glass and old tires .
Haikou workers remove rebar from rubble .

Under Baustoffrecycling means the reuse and recycling of building materials .

Mineral construction waste represents the largest waste stream in Germany. The reuse of this mineral construction waste falls under building material recycling with the aim of re-using it as building material.

history

Premodern

Building materials that were once laboriously extracted have already been reused many times in the past. These early forms of building material recycling can be proven by many historical examples. The Dorians on Crete used around 600 BC Building materials from the ruins of old Minoan buildings, the streets of the Incas were partly paved with rubble stones from the Wari culture . In 1176, stones from old pyramids were used to build the Citadel of Cairo . The ruins of ancient Roman structures were sometimes used as a kind of quarry when the buildings were not completely converted. In the period between late antiquity and the early modern period , so many buildings were destroyed and the building materials used for new buildings. Materials like travertine or tuff were so easy to procure, but the representative character of artistic spoilage probably also played a role.

Debris recovery in the post-war period

In Central Europe, the modern recycling of building materials became important again after the extensive war damage in the Second World War . In post-war Germany, under the terms rubble recovery, rubble clearing or rubble clearance, industrial building material recycling was sometimes carried out. In many cities, companies or offices were founded to organize the processing of building materials on a large scale, such as the rubble recycling company in Frankfurt am Main . Both civilians , including the so-called rubble women , and internees worked there . To transport the debris to and from the often centrally established recycling facilities were rubble paths built. Trucks were later used for this .

The rubble contained many different components. Whole parts such as masonry bricks or natural stones were sorted out by hand and freed from mortar , metals and wood were also picked out and recycled. The processing plants often had screening machines and impact or jaw crushers , so that the debris could be separated and processed according to grain size . In the early 1950s , for example, in Cologne , the systems were often relocated to an industrial area , where they were in operation until the 1960s. About 40% of the debris could only be reused as fine debris to a limited extent. These remains were piled up to form mountains of rubble .

Since the 1970s and 80s, the topic has attracted renewed attention, this time under the aspect of resource conservation and environmental protection .

Construction waste in Germany

The monitoring reports of the construction cycle management system have been documenting the accumulation and whereabouts of construction waste every two years since 1995 and thus show the building material recycling rate in Germany. The annual surveys of the generation, recycling and disposal of waste by the Federal Statistical Office serve as the database . The monitoring report focuses on the mineral construction waste, today divided into:

Accumulated quantities in million t
year 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016
Soil and stones 136.8 128.0 163.6 140.9 123.3 106.0 107.3 105.7 109.8 118.5 125.2
Gypsum-based construction rubble and construction waste 58.1 58.5 54.5 52.1 50.8 57.5 58.7 53.7 52.2 55.2 59.1
Road break 17.6 14.6 22.3 16.6 19.7 14.3 13.6 14.1 15.4 13.6 16.0
Construction waste 7.4 4.0 11.8 4.3 1.9 10.9 12.4 13.0 14.6 14.6 14.3
total 220.0 205.1 252.2 213.9 195.7 188.7 192.0 186.5 192.0 202.0 214.6

Use of by-products and waste

In addition to used building materials, other by-products and waste can also be processed into building materials, especially in the form of aggregates and aggregates .

Incineration ashes

In the incineration several species arise from ashes. Recycled incineration ashes can be used in road construction , earthworks and civil engineering . Before doing this, they must first be stored wet for a few months in order to achieve a certain degree of stability .

Power plant by-products

When generating electricity in combustion power plants , there are several by-products.

Boiler ash

Boiler ash (also called boiler sand, wet ash or coarse ash) is created when coal dust is fired in the combustion chamber. Some types can be used as aggregates in road and earth construction.

Melting chamber granulate

Melting chamber granulate is produced during the combustion of hard coal in power plants with melting chamber firing. The mineral admixtures in the coal are melted down during the firing process and then suddenly cooled in a water bath. In this way, a vitreous mineral mixture is created, in which, however, the individual grains are cracked due to the cooling process and have a low strength. This mineral mixture is qualitatively improved by breaking it so that it can withstand high demands. Can be used as aggregate, for example

Fly ash

Bricks with a high proportion of fly ash.

Fly ash is created when coal is burned ; it is obtained from the dedusting process during flue gas cleaning . A distinction is made between fly ash from hard coal and fly ash from lignite . In Germany, fly ash from hard coal is mainly reused, mainly as an aggregate for concrete and cement . Heavy metals can accumulate in fly ash during incineration , so eluate limit values ​​must be observed for further use. Fly ash is also used in civil engineering.

REA plaster

In flue gas desulphurisation , sulfur oxides react with lime and form gypsum , which can then be used as a building material.

Slag from the metal industry

Iron silicate slag from copper production , used as bank reinforcement.

A large number of different types of slag are produced in the production and processing of metals. Lump slag is used, among other things, as a building block or artificial aggregate in many areas of the construction industry . Blast furnace slag extracted from slag is mainly used for the production of blast furnace cement and Portland slag cement .

Quarry waste and secondary rocks

Debris from quarries comes from weathered surface layers or poor quality areas of the rock occurrence, the secondary rocks are a by-product in mining . These natural soils and stones can be used in earthworks like other excavations .

Waste glass

Used glass can be used in shredded form as an aggregate in asphalt, but glass recycling is so effective in Germany that the raw material is rarely used as a building material. In the United States , used glass is more common. There, top layers with around 10-15% shredded waste glass are installed, which are also called "glassphalt".

The foam glass insulation material is now largely made from old glass.

Old rubber

Rubber , for example from old tires, can be used to modify bitumen . This bitumen-rubber mixture can be used for surface treatment of ceilings that have become cracked and to prevent reflection cracks . In Australia and the United States attempts were made in the 1980s to use scrap rubber in bitumen-rubber mixtures. In Australia it was found that used rubber from truck tires gave better results than rubber from car tires.

Waste paper

Waste paper is primarily used to produce recycled paper , newsprint and cardboard . From waste paper but can also cellulose - insulating materials are produced. Waste paper can also be used as a fiber additive in stone mastic and poured asphalt for better binder distribution and to stabilize the asphalt.

plastic

Recycled plastics can in principle also be used as building materials. Similar to rubber, plastic waste can also be used as an additive to bitumen.

Sawdust

Wood chips are a by-product of the timber industry . Mainly chipboard and insulation materials are extracted from them . In the USA , sawdust is sometimes used to build forest roads . The material is significantly lighter than conventional building materials, so roads can also be built on peaty soils.

Processing of individual building materials

Recycled aggregates

Manufacturing

Many materials can be recycled into aggregates , which are known as RC building materials in road construction . The production is similar to the production of natural aggregates in quarries or similar plants.

Today, processing is mostly done by machine, and there are stationary, semi-mobile or mobile recycling systems. Mobile systems can be set up directly on the construction site , but are usually simpler and not as efficient as stationary systems. Processing systems that stand on runners and can be pulled over short distances are referred to as semi-mobile (semi-mobile). Processing plants always consist of at least one feeding device, a crusher and sieve unit and the connecting conveyor belts .

The feed unit feeds the following machines with the delivered material. It also ensures that the system can work as continuously as possible if the delivery by truck is irregular. The feeding device also includes a first screening, the pre-screening, during which fine substances (earth, sand, etc.) are removed.

The breaker unit can consist of one or more breakers. Common types of crushers are jaw , gyro , roller , impact and hammer crushers , each with their own advantages and disadvantages. The crusher unit also includes the sorting out of metals with magnets .

In the secondary sieving, the broken material is sorted according to grain size , mostly oscillating and vibrating sieves are used .

In addition, it may be necessary to sort out impurities. Unwanted components can be removed by hand on a reading belt, which is still necessary today, especially in the case of coarse contamination. Small foreign matter can be removed mechanically after breaking, either with an air classifier or a so-called aquamator, which washes out impurities with water.

Production quantities

Recycled aggregates can be made from construction waste such as stones or rubble or other by-products. In Germany in 2016 around 12.7% of the aggregates used were RC building materials, 5.2% were obtained from industrial by-products.

Production of aggregates from construction waste in Germany in million t
year 2006 2008 2010 2012 2014 2016
Soil and stones 8.2 8.9 9.8 10.7 12.1 11.3
Rubble 41.9 44.4 41.6 40.4 42.5 45.5
Construction waste 0.0 0.3 0.3 0.3 0.2 0.2
total 63.6 66.6 65.2 66.2 67.6 72.2

use

Recycled aggregates can be used like the natural building material. The possible areas of application for recycled building materials result from a combination of local installation conditions, material class and structural requirements. If they are used for the production of concrete, they are also referred to as recycled concrete . The main areas of application in 2016 in Germany were road construction and earthworks .

concrete

In the case of concretes, either the aggregate is reused (fresh concrete recycling) or the concrete is processed into aggregates.

asphalt

Asphalt can be fully reused if it is reheated. It can be reshaped on site or broken first, processed into asphalt granulate and then rebuilt (cold recycling).

plaster

Gypsum waste, for example in the form of used gypsum boards , must be processed separately from the rest of the building rubble, as otherwise it would render the aggregate unusable. Properly prepared gypsum is called recycling gypsum or RC gypsum.

Environmental requirements

There are numerous environmental regulations that deal with the use of substitute building materials - in addition to recycled building materials, this includes, for example, household waste incineration ash or mineral waste from industrial processes. The protection of the soil and the groundwater is decisive for the use of these substances .

Legal framework and standards

European Union

Germany

As long as the nationwide regulation in the form of the Substitute Construction Materials Ordinance or Shell Ordinance is still in progress, country-specific requirements apply. With regard to the possibilities of recycling mineral residues, most of the federal states refer to the LAGA M20 communication of the federal state waste work group from 1997 and 2003. However, there are also federal states with their own regulations. In road and path construction , the Research Association for Roads and Transport (FGSV) is responsible for the development of national regulations.

Austria

  • Waste Management Act

In 2015/16 the national recycling building materials ordinance came into force in Austria , it replaces older specifications and sets standards for the dismantling, processing and reuse of building materials.

Switzerland

literature

Directives and laws (selection)

  • Federal / State Working Group on Waste: Communication 20: Requirements for the recycling of mineral residues / waste - Technical rules . 5th edition. November 6, 2003 ( laga-online.de [PDF; accessed June 14, 2020]).
  • State Ministry for the Environment, Health and Consumer Protection (Ed.): Requirements for the recovery of building rubble in technical buildings . Munich December 9, 2005 ( bayern.de [PDF; accessed June 14, 2020]).
  • Research Association for Roads and Transport: Working group for aggregates, unbound construction methods: Leaflet on the use of recycled building materials in earthworks and road construction (M RC) . FGSV-Verlag, Cologne August 2019.
  • Austrian recycling building materials regulation
  • Guideline for the recovery of mineral construction waste . In: Federal Office for the Environment FOEN (Ed.): 2006 . 2nd Edition. 2006 ( admin.ch [PDF; accessed on June 16, 2020]).

Specialist literature

  • Anette Müller: Building material recycling: creation - processing - recovery . Springer Vieweg, Wiesbaden 2018, ISBN 978-3-658-22987-0 .
  • Ernst-Ulrich Hiersche, Thomas Wörner: Alternative building materials in the building industry: environmental compatibility, building technology, plant engineering and economic efficiency . Ernst & Sohn, Publishing House for Architecture and Technical Sciences, Berlin 1990, ISBN 3-433-01194-X .
  • H.-P. Andrä, R. Schneider, T. Wickbold: Building material recycling: types, quantities and qualities of the building materials used in building construction . 2nd Edition. ecomed, Landsberg 1994, ISBN 3-609-65410-4 .
  • Guntram Kohler (Ed.): Recyclingpraxis Baustoffe . 2nd Edition. TÜV Rheinland publishing house , Cologne 1994.
  • M. Lorenz, J. Lorenz: Handbook road construction. Fraunhofer IRB Verlag, 2006, ISBN 3-8167-7083-5 , pp. 202 to 204.

Web links

Individual evidence

  1. ↑ a b c d Ernst-Ulrich Hiersche, Thomas Wörner: Alternative building materials in the building industry: environmental compatibility, building technology, plant engineering and economic efficiency . Ernst & Sohn, Publishing House for Architecture and Technical Sciences, Berlin 1990, ISBN 3-433-01194-X , p. 6-13 .
  2. ↑ Paul Zanker : The Ruin - From building material to the generation of strong feelings: the Roman ruins and their viewers . In: Neue Zürcher Zeitung . No. 283 , December 5, 1999 ( swisseduc.ch [accessed June 12, 2020]).
  3. ↑ a b c d e Construction circular economy: Mineral construction waste monitoring 2016: Report on the occurrence and whereabouts of mineral construction waste in 2016 . Berlin December 2018 ( Kreislaufwirtschaft-bau.de [PDF; accessed June 13, 2020]).
  4. ↑ Ernst-Ulrich Hiersche, Thomas Wörner: Alternative building materials in the building industry: environmental compatibility, building technology, plant technology and economic efficiency . Ernst & Sohn, Publishing House for Architecture and Technical Sciences, Berlin 1990, ISBN 3-433-01194-X , p. 33 f .
  5. ^ Economic Association of Mineral By-Products eV: Kesseland. Retrieved June 13, 2020 .
  6. ↑ Wolfgang Linden, Iris Marquardt (Hrsg.): Ecological building materials lexicon building products, chemicals, pollutants, ecology, interior . 4th, completely revised and enlarged edition. VDE Verlag, Berlin 2018, ISBN 978-3-8007-3232-6 , pp. 547 .
  7. ↑ Economic Association of Mineral By-Products eV: Melting chamber granulate. Retrieved June 13, 2020 .
  8. ↑ Wolfgang Linden, Iris Marquardt (Hrsg.): Ecological building materials lexicon building products, chemicals, pollutants, ecology, interior . 4th, completely revised and enlarged edition. VDE Verlag, Berlin 2018, ISBN 978-3-8007-3232-6 , pp. 193 .
  9. ↑ a b c Ernst-Ulrich Hiersche, Thomas Wörner: Alternative building materials in the building industry: environmental compatibility, building technology, plant technology and economic efficiency . Ernst & Sohn, Publishing House for Architecture and Technical Sciences, Berlin 1990, ISBN 3-433-01194-X , p. 40 ff .
  10. ↑ Federal Highway Administration (ed.): User Guidelines for Waste and Byproduct Materials in Pavement Construction: FHWA-RD-97-148 . WASTE GLASS, 2008 (American English, dot.gov [accessed June 13, 2020]).
  11. ^ John WH Oliver: Modification of Paving Asphalts by Digestion with Scrap Rubber . In: Transportation Research Record . No. 821 , 1981 (American English, trb.org [PDF; accessed June 13, 2020]).
  12. ↑ Wolfgang Linden, Iris Marquardt (Hrsg.): Ecological building materials lexicon building products, chemicals, pollutants, ecology, interior . 4th, completely revised and enlarged edition. VDE Verlag, Berlin 2018, ISBN 978-3-8007-3232-6 , pp. 115 f .
  13. ↑ Rodger A. Arola, Ralph J. Hodek, John K. Bowman, Gary B. Schulze: Forest Roads Built With Chunkwood . In: Chunkwood: Production, Characterization, and Utilization . 1988, p. 29-44 (American English).
  14. ↑ a b c d e Ernst-Ulrich Hiersche, Thomas Wörner: Alternative building materials in the building industry: environmental compatibility, building technology, plant engineering and economic efficiency . Ernst & Sohn, Publishing House for Architecture and Technical Sciences, Berlin 1990, ISBN 3-433-01194-X , p. 167-187 .
  15. ↑ Berlin Senate Department for the Environment, Transport and Climate Protection: Recycling of gypsum. In: Berlin.de. Retrieved June 13, 2020 .
  16. ↑ Jörg Demmich: Gypsum recycling: Still quite a few stones in the way. In: EU recycling. Retrieved June 13, 2020 (German).
  17. ↑ Federal Ministry for Agriculture, Regions and Tourism : Recycling-Baustoffverordnung. Retrieved June 16, 2020 (Austrian German).