Recycled Waste in Concrete

Transcription

1 Recycled Waste in Concrete Ing. Vladimíra Vytlačilová, PhD. This presentation was created thanks to the support of FRVŠ project 915/2013 B1d Tools for teaching design of concrete and masonry structures in English

2 Recycled materials in the building industry Application of recycled materials in the building industry is important for sustainable development and keeping of primary sources of each country.

3 Terminology Recycled concrete aggregates (RCA) are aggregates produced by the crushing of original concrete (inorganic material previously used in construction and principally comprising crushed concrete). Recycled aggregate concrete (RAC) is concrete produced from recycled aggregates or a combination of recycled and conventional aggregates such as sand, gravel, or crushed stone. Sometimes is referred to as new concrete. RCA is obtained from crushing demolished concrete structures, discarded precast elements and unused hardened concrete.

4 Terminology Construction and demolition waste are waste materials which arise from the construction or demolition of buildings and/or civil engineering infrastructure, including hard C&D waste and excavation waste, whether segregated or mixed. Could be broken concrete, bricks, masonry, soil, asphalt, tiles, wood, plastic, metal a.o. from demolished buildings. Recycled concrete (RC) or concrete rubble (CR) is hardened (old) concrete that has been processed for reuse, usually as aggregates. It has been demolished and removed from pavements, bridges, foundations, or buildings and crushed into various sizes for reuse. Recycled masonry or brick (RM) or masonry rubble (MR) is old masonry from building that has been processed for reuse, usually as aggregates. It contains a certain amount of mortar debris.

5 Waste hierarchy The waste hierarchy is a classification of waste management options in order of their environmental impact

6 Construction and Demolition waste (C&DW) Construction and Demolition waste constitutes a major portion of total solid waste production in the world, and most of it is used in land fills Quarter to third of the weight of all produced waste

7 Effective way to reduce the CDW The most effective way to reduce the waste problem in construction is agreed in implementing reuse, recycling and reduced the use of a construction material in construction activities. Construction& Demolition Waste Recycling Reprocessing Reuse Relocation

8 Life cycle of building products

9 Benefits of Recycling Reduces the amount of waste sent to landfills and incinerators Conserves natural resources such as timber, water, and minerals Prevents pollution by reducing the need to collect new raw materials Saves energy Reduces greenhouse gas emissions that contribute to global climate change Helps sustain the environment for future generations Helps create new well-paying jobs in the recycling and manufacturing industries

10 Construction and Demolition (C&D) waste Construction waste occurs on account of building constructions and building renovations,and results from surplus material (excess supplies), damaged or broken material, cut-off pieces, processing waste, dismantled shuttering. Demolition waste can result from natural disasters (earthquakes;vandalism and other man-made events; accidents (impact, explosions,fires, collapse of weak structures); or from the demolition of built structures (including roads,bridges, etc.) for renovation or complete removal or renewal.

11 Construction and Demolition (C&D) waste Concrete, Masonry Metal Hazardous Materials Wood Glass Paper Cardboard Drywall Plastic

12 Recycling centre

13 Crushing and screening plant

14 Recycled aggregates

15 Recycled aggregate Masonry rubble Concrete rubble Fraction: 0/4 mm, 0/8 mm, 0/22 mm, 0/32 mm

16 Recycled Motivation aggregate - Recycling Increasing amount of concrete and masonry waste in the CR ~1600 [kt]/ Year 2010 Masonry waste ~1200 [kt]/ Year 2010 Concrete waste ~ 22-27% from total production of building waste Only very little recycled aggregate is used for structure in building industry.

17 Recycling in the Czech Republic Mostly recycled materials come from the recycled waste of bricks, concrete, asphalt, mixed building waste, various types of aggregates and soil. There are more then 200 recycling centers (static and mobile) and deposits, in the Czech Republic which process construction and demolition waste. The total yearly capacity of all the recycling centers in the Czech Republic is about 7.5 million tons, which is 50 % more than the actual production of recycled materials.

18 Recycling in CR The Association for development in recycling of building materials (ARSM) summarizes the yearly output C&DW since Since 2007 summarizes the yearly data of waste inclusive construction and demolition waste the Czech Environmental Information Agency (CENIA). This agency files the information of waste management in database ISOH. Between 2002 and 2006, the data were administered by the T. G. Masaryk Water Research Institute, a public research institution the Waste Management Centre.

19 Total production [kt] Recycling in the Czech Republic Total production of crushed demolition waste in recycling centers in the Czech Republic (in thousand tons) Year 834 Masonry [ARSM] Concrete [ARSM] Masonry [CENIA] Concrete [CENIA]

20 Criteria in recycling process Technological criteria Technical criteria Organizational criteria Economical criteria R E C Y C L I N G Ecological criteria Legislative criteria Material criteria Socio - cultural criteria

21 PET bottles waste waste problem Fibres to fibre reinforced concrete Waste PET bottles Fibres cut from waste PET bottles: tensile strength ~ MPa length ~ mm width ~ 1-2 mm

22 Fibre reinforced concrete from masonry rubble

23 Use of recycled concrete Concrete Blocks Source: