Following a public vote that branded it one of the worst streets in Britain, Maid Marion Way in Nottingham needed urgent modernisation and traffic control improvements. For a quick, mass bulk fill solution to seal a network of subways beneath the carriageway and start remodelling the site, Propump Engineering Ltd was called in.
The UK’s first foamed concrete specialist, Propump placed over 2000m3 of foamed concrete in just one week. The works soon saw the 1960’s dual carriageway transformed from a roundabout with four pedestrian subways, each served by stairways and ramps, to a light controlled junction with wide surface pedestrian crossings.
“Foamed concrete was chosen because we needed to fill the subway voids with a material that wouldn’t settle,” explained Chris Capewell at Nottingham City Council. “We had to be certain that the road surface would stay in place. To have used non-cementitious bulk fill would have required the timely and difficult process of compacting the material tightly to ensure there were no spaces. Foamed concrete was therefore the ideal solution!”
Lightweight and self compacting, the foamed concrete was manufactured on site via a Propump In-line Foamed Concrete System (IFCS) and pumped through a complex arrangement of input and venting hoses to quickly fill the voids. Super efficient, the system allows full base material (sand, cement, water) deliveries and processes them on a continual basis into the specified foamed concrete.
Designed and built exclusively by Propump, the IFCS pumps base material through a specially designed squeeze pump to an injection chamber housed on the rig. From here, the preformed foam is injected into the base material and forced through a series of in-line mixers. The two are then blended together to produce the foamed concrete which for this project was specified as being an 1100kg/m3 plastic density.
An extremely efficient method of making foamed concrete, the system provides a significantly more economic and environmental approach in comparison to other methods of foamed concrete production as well as being much safer than traditional concrete pumps due to lower operational pressures.
Now complete, the remodelling of Maid Marion Way and the inclusion of wide pedestrian crossings has restored a direct visual and psychological link across the busy road – helping retain the city’s competitive position for retail, business and tourism.« Foamed concrete reaches the Pinnacle