Bridge Infill: Lord Nelson Bridge

GS Foam Concrete provide bridge infill at the Lord Nelson Bridge, M1 motorway, Wakefield.

This particular bridge infill was a void spanning all six lanes of the M1 motor way in Wakefield Yorkshire, the total volume used on this project was 2866 m³ using a mix design of sand/cement ratio of 4/1 with a plastic density of 1100 kgs . The infill was undertaken with no traffic management having to be put into place so not to cause any delays or extra cost.

Bridge Infill

The foam concrete was pumped via a 28 metre concrete boom into the centre of the bridge which flowed under gravity to the shuttering at both sides of the void. The foaming of the concrete took place on site requiring minimal space as we are a fully contained unit and we only require enough space for an average size van with wash out facilities.

The mobile foaming unit mixes water with our unique foaming agent which combined together produces the foam which is injected into the drum of a 6m or 8m concrete mixer. The benefit of this for bridge infill is the foam concrete will not loose its plastic density as it would if it was in transit from a concrete plant so therefore we have greater control over its stability.

Concrete Cavity Fill

To ensure that the void was completely full steel breather pipes were erected to the bridge ceiling, along with steel pipes for pumping the foam concrete through. This method allows complete concrete cavity fill, ensuring that the entire void will be completely full so not to leave any gaps or voids.

The above picture illustrates just how full the bridge actually is with no gaps or voids at all with an average compressive strength of 1.5 n/mm². All this was completed in just three weeks.