Concrete segment visit

Riverlinx JV recently visited the tunnel lining contractor Banagher Precast Concrete in Ireland to oversee the production of the concrete segments that are being used for the Silvertown Tunnel.

Fig.1. Tunnel segment inspection

Work is now moving apace to pour over 9,000 segments. The effort and passion of the Banagher team was very apparent and they were keen to highlight some of the innovative carbon savings on the project.

Working closely with Riverlinx the team at Banagher developed a concrete mix containing 40% GGBS (ground granulated blast furnace slag which is a recycled by-product of steel) giving an automatic carbon saving of 40% per unit.

In late 2021 Banagher installed 1,000 PV solar panels over their production halls which to date produces approximately 30% of their energy requirements, the remaining power required for production is from another renewable source, Airtricity, ensuring net zero energy consumption for the manufacturing of the tunnel segments.

Fig.2. 1,000 new PV solar panels installed on production halls

The production halls are also insulated, maturity computers measure strength gain and only light covers over the precast moulds are required for moisture loss and to gain strengths, this combination eliminates the requirement for energy hungry processes such as heat or steam curing.

Fig.3. Bespoke platforms and edge protection on the static moulds in the insulated production hall

As part of their ongoing CRS campaign the company has already planted 6.5 acres of trees and unique to the Silvertown Tunnel project Banagher has committed to plant 1 hardwood tree for every precast ring manufactured. A hardwood tree absorbs approximately 20 kgs of carbon per year and Banagher will plant 1,200 trees which will offer 24 tonnes of carbon absorption annually.

Fig.4. Tunnel segments in storage at Banagher Precast Concrete