£17m Bromford flood alleviation scheme, Birmingham • Cemfree

CO2 savings of up to 90% compared with using a traditional hot AC20 asphalt mix

In order to protect the residents of Bromford from potential flood risks from the River, Tame, the Environment Agency joined in partnership with Birmingham City Council and Birmingham Municipal Housing Trust to improve the existing flood defence scheme. The project aimed to protect 1589 homes along the riverbanks and to reduce the flood risk to a further 42 non-residential properties that are also close by.

Main contractor

Client

By replacing the Portland cement, it was predicted a total of 60 tonnes of CO2 was saved.

To achieve this it was decided that a revision of the existing scheme was required, adding to the existing elements rather than taking them away.

The project design was broken down into three main sections. These were:

The flood walls on the left bank
A series of separate flood walls on the left bank
2 kilometres of earth works on the right bank, with 5 more flood walls and a new cycle path.

An innovative and environmentally friendly design was chosen when it came to building the new cycle path. The path would be 2.5km long and require an extraordinary amount of asphalt and concrete to complete, materials that hold significantly high volumes of embodied carbon.

Cemfree worked closely with Accumix to replace the Portland cement (PC) with a Cemfree binder in the concrete mix by. The concrete was used to bed the kerbstones, stretching the length of the path.

To enhance carbon savings further on the paths, the project also utilised O.C.O Technology Ltd.s carbon negative aggregate, made from waste material from the treatment of flue gases from Energy Waste (EfW) Plants. This was mixed with surfacing specialist Topplesfields ToppFoam, a cold foamed bitumen asphalt that incorporates recycled aggregates.

By replacing the Portland cement, it was predicted a total of 60 tonnes of CO₂was saved.

Andy Lusher, the supply chain manger for Jackson Civil Engineering, believes that with these successful trials, they can be confident in specifying Cemfree for future projects.