Our most recent work has seen us slipforming residential complexes in three UK cities. We have visited Liverpool, London & Portsmouth. We have also been busy in Bolton, Suffolk, & Cumbria to complete a wide range of RC works.
Our works ranged from pouring underwater concrete in Sellafield to constructing 70m high Residential lift Cores in London. We have also been involved in deep shaft pre-construction works on The Thames Tideway Tunnel.
Below are our 3 most recent projects:
Parliament Street Liverpool
We provided the equipment hire and rig operator on this scheme, for ease of construction we designed all our yoke legs to avoid any clashes with the door openings. This made it more efficient for the contractor to install the door frames as they can be installed earlier due to no cross bars being in the way. This was also good for the slipform system as we had all our jack rods cast in concrete and did not require the contractor to install bracing to our tubes.
There was 3 lift shafts and 1 stairwell within this rig which was constructed at a rate of over 3m per day.
We provided our fully inclusive package on this scheme, using 200mm walls which require precision pouring to make sure the concrete is placed in the correct layers. The depth of the set concrete needed to be monitored constantly to remove the risk of dragging walls.
There was wall adaptions at Level 9 & 20 where some of the walls are reduced. There was also an enhanced finish required on the stair wall. We achieved this by sliding on green concrete which allowed us to make sure that the concrete coming out of the base of the shutter is workable and not hard. We were able to steel float the walls and give them the enhanced finish required by the client. We also had to do extensive concrete trials on this project to cover all eventualities as it was in London. We had a range of 6 mixes that we could use depending on the time of day as the traffic can delay the concrete wagons getting to site and also the ambient temperature had an affect on the setting time. The concrete setting time is key to the progress and the enhanced finish quality. We had the added challenge of constructing a straight wall 15m long with no concrete ties back to the rest of the walls. We had to install a complex arrangement of temporary stability propping each floor while we slide that allows us to bring the wall to the full height of 70m. The rest of the core was made up of 2 lift shafts a stairwell and a large lobby. In total there was 30 men working on this project.
On this scheme we provided our fully inclusive (plug in) package. We included the following: Slipform management, engineering, banksmen, joiners, fixers, concreters, Slipform rig driver, Slipform equipment in it’s entirety inclusive of all decking, cladding, temporary power and all the small tools to complete the works.
During the construction period we had 28 men each day and climbed at a rate of over 3m per day. There were embedment plates at each floor, to make sure that these were correctly installed at each floor we welded all of these in place to make sure that there was no movement. We had the challenge of 6m 32mm vertical reinforcement bar for the first 5 lifts, with each bar weighing 38kgs it was a 3 man job to install each vert. The core compromised of 3 lift shafts, a lobby and a stairwell. There was also 2 hold points on the core for the collapse radius of the crane, as Portsmouth rail station is in within the radius.
For more information, visit slipformengineering.co.uk