Over 3,000m3 of Propump Engineering’s lightweight foamed concrete has been used to fill a subway system incorporating a derelict night club and redundant shop units beneath Civic Drive roundabout in Ipswich – the most important part of the £21 million ‘Travel Ipswich’ regeneration of the town’s transport network.
Working with main contractor Skanska, Propump Engineering was appointed to deliver a foamed concrete application into the roundabout’s underground atrium structure, to enable conversion of the roundabout into a traffic light-controlled crossroad junction.
Propump utilised its experience and practical expertise to deliver the complex and highly skilled application within a strict budget. Pumping large volumes of foamed concrete on each of the nine days, and with a variety of soffit heights to consider, Propump had to ensure each individual unit was full.
Headwalls were erected at the subway entrances and sacrificial hoses installed to pump the concrete in, whilst allowing air to escape so no voids were left.
With density of the material critical due to the high water table, Propump ensured the foamed concrete was lightweight, but dense enough for floatation not to become an issue. After filling, cores were cut from the foamed concrete mass pour and then analysed to check that the correct density was maintained throughout the layers.
Upon completion in summer 2014, the new and improved road network created by Travel Ipswich scheme will deliver better journey time reliability, increased safety and reduced congestion – with foamed concrete playing a crucial role in its success.« Not going underground: Propump enables subway fill without road closures