Mixed hardcore waste refers to a mixture of various types of waste materials that are generated during construction and demolition activities, including bricks, concrete, tiles, ceramics, soil, rock, and other debris.

The scale of waste generated is staggering - comprising of around 40% of mineral waste and 30% all waste generated by the UK. In most instances, buildings are demolished in order to be replaced and therefore both demolition and construction waste arise where construction activity is geographically concentrated.

Construction and demolition waste varies considerably by site and source, but in the UK the majority of building stock is masonry built and the mineral fractions made up of masonry and concrete dominate. The primary recovery route for these materials is in the production of recycled aggregates and fill material, through a mixed recycling stream.

Whilst the reported recycling rate for this type of material is very high (92.3% in 2018), the vast majority of material is downcycled for use in low-value applications such as backfill, road construction and can represent a highly wasteful disposal route for what were primarily carbon-intensive building products.