case study: HS2 Pipeline Diversion
GS Foam Concrete were awarded the contract by Murphy Pipelines to infill the redundant 900mm gas pipelines in Tamworth. The main client, Cadent, required a product that would flow over 300 linear metres to reduce the number of movements between pumping points. The main issue with this project was the location of the pipelines as the access points were across fields and reaching these positions was difficult.
Murphy Pipelines contacted us to provide a material that would flow 300 metres and achieve a nominal strength of 3n/mm2. We provided our client with our specially designed foamed grout called P1224. The mix properties are: Cem1, GGBS, water and CLC synthetic foaming admixture dispensed via our foam generator machines.
The wet density of the material is 900kgs and after 28 days, the final dry density is 800kgs.
We provided Murphys with a steel 100mm pipe which they welded on to the start of the pipeline and a vent pipe for the end of the pipeline to allow the air to escape and eventually show the foamed grout.
GS Foam provided a large concrete pump which was needed to force the material through the pipeline. The concrete pumping company had to lay along the ground 280 linear metres of pipes to reach the steel sacrificial pipe which was welded on to the pipeline.
The foamed grout was pumped through the delivery pipes and flowed 300lm to the vent at the end of the pipeline. To ensure safety, GS Foam installed gate valves at both ends and once the material showed, these valves were closed to enable us to disconnect the delivery pipeline.
The infill was completed in one day and the volume placed to complete the project was 183m3.