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Wst 02 Recycled aggregates
To recognise and encourage the use of recycled and secondary aggregates, thereby reducing the demand for virgin material and optimising material efficiency in construction.
The following is required to demonstrate compliance:
One credit - Recycled aggregates
- The percentage of high grade aggregate that is recycled or secondary aggregate, specified in each application (present) must meet the following minimum % levels (by weight or volume) to contribute to the total amount of recycled or secondary aggregate, as specified in Table 54 .
- The total amount of recycled or secondary aggregate specified, and meeting criterion 1, is greater than 25% (by weight or volume) of the total high grade aggregate specified for the project. Where the minimum level in criterion 1 is not met for an application, all the aggregate in that application must be considered as primary aggregate when calculating the total high grade aggregate specified.
- The recycled or secondary aggregates are EITHER:
- Construction, demolition and excavation waste obtained on-site or off-site; OR
- Secondary aggregates obtained from a non-construction post-consumer industrial by product source (see Relevant definitions section).
Exemplary level criteria
The following outlines the exemplary level criteria to achieve an innovation credit for this BREEAM issue.
- The percentage of high grade aggregate that is recycled or secondary aggregate, specified in each application (present) must meet the exemplary minimum levels (by weight or volume), as defined in Table 54 . Where this minimum level is not met, all the aggregate in that application must be considered as primary aggregate when calculating the total high grade aggregate specified.
- Where the total amount of recycled or secondary aggregate specified is greater than 35% (by weight or volume) of the total high grade aggregate specified for the project. Where the minimum level in criterion 4 is not met for an application, all the aggregate in that application must be considered as primary aggregate when calculating the total high grade aggregate specified.
- The contributing recycled or secondary aggregate must not be transported more than 30 km by road transport.
Checklists and tables
Table 54 Minimum levels (by weight and volume) of high grade aggregate specified per application (where present) that is recycled or secondary aggregate
|Bitumen or hydraulically bound base, binder, and surface courses for paved areas and roads
|Concrete road surfaces
|Granular fill and capping (see Relevant definitions section)
|Shell and core
|Applicable assessment criteria
Both options: All criteria relevant to the building type and function apply.
Refer to Appendix D – BREEAM UK New Construction and Shell and Core Project Assessments for a more detailed description of the above shell and core assessment options.
|Applicable assessment criteria
||All criteria relevant to the building type and function apply.
|Off-site recycled aggregates
||Where off-site recycled aggregates from construction, demolition and excavation waste are used, they should be produced according to the relevant Quality Protocol or comply with the relevant BS/EN standards for aggregates.
|Aggregates in off-site manufactured applications
||Where any of the listed applications have been manufactured off-site, the aggregate present in these applications should be included in the assessment of this issue.
||Interim design stage
||Final post construction stage
One or more of the appropriate evidence types listed in The BREEAM evidential requirements section can be used to demonstrate compliance with these criteria.
||Calculation confirming the amount of recycled or secondary aggregate to be used.
||Calculation confirming the amount of recycled or secondary aggregate used.
- Air cooled blast furnace slag
- Air cooled blast furnace slag is classified as a by product (rather than a waste) and can therefore be used as an aggregate without the need for a quality protocol. The slag used must meet the requirements of the European and BS Aggregates Standards that apply to the end use application (e.g. bitumen bound, unbound etc.)
- Granular fill and capping (as high grade aggregate)
- For granular fill to be considered a ‘high grade aggregate’, it must conform to one of the following classes under the Specification for Highway Works (SHW) Series 600 Earthworks:
If the application is capping, then granular materials should conform to one of the following classes under the Specification for Highway Works (SHW) Series 600 Earthworks:
- Class 6A, 6I and 6N - Selected well graded granular material
- Class 6B - Selected coarse granular material
- Class 6C, 6D, 6J and 6L - Selected uniformly graded granular material
- Class 6E, 6G, 6H, 6K, 6M, 6P and 6R - Selected granular material
- Class 6F (and the various sub classes) - Selected coarse and fine graded material
- Class 6Q - Well graded, uniformly graded or coarse graded material.
If the application is capping, then stabilised materials should conform to one of the following classes under the Specification for Highway Works (SHW) Series 900 Earthworks:
- Class 6F - Selected coarse and fine graded material
- Class 6S - Selected well graded granular material.
- Class 9A - Cement stabilised well graded granular material
- Class 9B - Cement stabilised silty cohesive material
- Class 9C - Cement stabilised conditioned pulverised fuel ash cohesive material
- Class 9D - Lime stabilised cohesive material
- Class 9E - Lime and cement stabilised cohesive material
- Class 9F - Lime and cement stabilised well graded material.
- Low grade aggregate uses
- Crushed masonry used as fill material for general landscaping is not considered to be high grade. This practice is now common place on construction sites due to increased landfill costs.
- Materials optimisation
- Refer to Mat 04 Insulation
- Post-consumer waste stream
- Waste materials generated by households or by commercial, industrial and institutional facilities in their role as end users of the product, which can no longer be used for its intended purpose. This includes returns of material from the distribution chain.
Waste materials generated during manufacturing processes are pre-consumer waste streams and are excluded. These streams include re-utilisation of materials such as rework, regrind or scrap generated in a process and capable of being reclaimed within the same process that generated it.
- Quality Protocol
- The purpose of a Quality Protocol is to provide a uniform control process for producers, from which they can reasonably state and demonstrate that their product has been fully recovered and is no longer a waste. It also provides purchasers with a product quality managed to common standards, which increases confidence in performance. Aggregates that do not meet the requirements of a Quality Protocol and/or relevant aggregate standards will still be considered waste.
Protocols exists for:
- Aggregates produced from inert waste
- Use of pulverised fuel ash (PFA) and furnace bottom ash (FBA) in bound applications.
- Recycled aggregates
- Recycled aggregates are those derived from reprocessing materials previously used in construction, e.g. crushed concrete or masonry from construction and demolition waste material.
- Secondary aggregates
- By products of industrial processes that can be processed to produce secondary aggregates. Secondary aggregates are subdivided into manufactured and natural, depending on their source.
Recognised non-construction post-consumer or post-industrial by products include:
- China clay waste
- Slate overburden
- Pulverised Fuel Ash (PFA)
- Ground Granulated Blast Furnace Slag (GGBFS)
- Air cooled blast furnace slag
- Steel slag
- Furnace Bottom Ash (FBA)
- Incinerator bottom ash
- Foundry sands
- Recycled glass
- Recycled plastic
- Spent oil shale
- Colliery spoil
- Municipal solid waste treatment residues.
The Environment Agency publishes and updates Quality Protocols:
BREEAM UK New Construction non-domestic buildings technical manual 2014
Reference: SD5076 – Issue: 5.0
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