Recycled Aggregate Calculator

Recycled aggregate (RA) is produced by crushing demolition waste - concrete, brick, masonry - into graded material suitable for construction. It must meet quality standards (BS EN 13242 for unbound applications) and can replace virgin quarried stone in many applications.

Suitable applications: sub-base for roads and hardstanding (Type 1), pipe bedding, general fill, drainage layers, and landscape features. It is generally not suitable for structural concrete (without specific testing and approval) or where contamination is a concern.

Recycled aggregate is typically 10-15% lighter (density 1.8-2.0 t/m³ vs 2.0-2.2 t/m³ for virgin) and may have a slightly lower CBR (60-80% vs 80-100%). Note that layer thickness is not set by the relative CBR of the two products: under DMRB CD225 (formerly HD25/26) pavement foundation thickness is designed against the subgrade CBR/surface modulus of the ground beneath, not the sub-base material. A recycled sub-base that meets the BS EN 13285/13242 grading and the specified soaked CBR is acceptable at the design thickness. Quality has improved significantly and many recycled products match virgin performance for Type 1 sub-base and general fill.

Recycled aggregate is typically 30-50% cheaper than virgin per tonne, depending on location and availability. The lower density means you need fewer tonnes per cubic metre. Combined, total cost savings of 25-45% are common for sub-base and fill applications.

Using recycled aggregate reduces: quarrying impact, landfill waste, and aggregate levy liability (recycled and other previously-used aggregate is exempt from the UK Aggregates Levy, which rose to £2.16/tonne on 1 April 2026). On embodied carbon, the cradle-to-gate footprint of recycled crushed aggregate is broadly comparable to virgin crushed rock - both around 5 kgCO2e/tonne in the ICE database (Circular Ecology). The net carbon benefit comes mainly from avoided quarrying and shorter local haul, and is transport-dependent: peer-reviewed LCAs report reductions of roughly 20-45% where the recycling plant is close to site, but recycled can be HIGHER than virgin once delivery exceeds about 15 km. The older claim of a fixed 60% saving is not supported by the data.