Materials

• 15% Reduction in material consumption across the Project lifecycle
• 100% Timber is reused/recycled or from sustainable sources e.g. AFS/FSC
• 10% Cement replacement material (by mass) in concrete
• 10% Recycled materials in road and subbase (including Reclaimed Asphalt Pavement)

Concrete, steel, asphalt, and aggregates are the main materials used in construction. JHCPB is focused on investigating low carbon alternatives to reduce emissions related to material consumption in tunnelling and civil construction works. During the review period JHCPB used 255,774.62 m3 of concrete, 13,898.14 tonnes of steel and 50,736.19 tonnes of quarry materials in construction. Project to date values are provided below.

The Project has used ~2600m3 of low carbon concrete, achieved over 45.9% cement replacement, 55.8% recycled material in road base/subbase and procured 92.8% of total timber from sustainable sources.

• Use of glass sand as a replacement to virgin sand within flowable fill applications in tunnelling works
• Use of bespoke low carbon concrete mixes which incorporate a higher percentage of Supplementary Cementitious Materials (above 50% cement replacement) in R53 applications
• Use of Emesh recycled plastic fibres in lieu of traditional reinforcing steel in footpaths
• Research and development into the use of geopolymer concrete
• Beneficial reuse of tunnel spoil on site for civil works e.g. backfilling of declines and shafts
• Optimised design to reduce re-work and material usage including the removal of pavements in ancillary tunnels
• Utilisation of materials with Environmental Labels (Environmental Product Declarations)
• Use of recycled materials in road base and retaining walls
• Investigating circular economy initiatives within our waste streams