At BEC we have the capability, knowledge and skills to design and build chimney structures and a vast variety of different projects involving slip-form construction techniques.
Slip-forming is a continuous construction technique that operates around the clock forming concrete with the use of moving formwork. Significant time savings can result using this system. The system uses a shallow form, purpose built to the concrete profile required, that is continuously lifted using a hydraulic jacking system. The form shutter is supported by the slip-form rig that also lifts as the pour progresses.
Our staff members have a wealth of experience in the slip-forming of chimneys, tanks and silos.
BEC owns all the necessary specialised equipment needed to construct slip-form structures. This equipment can be packed into 20’/40’ containers and shipped anywhere in the world.
:: Slipform Construction ::
Slipform Construction Video
The lifting rate (or speed) of rig is determined by the slip-form technician and is based on speed of the placement of the concrete and reinforcement as well as the setting time of the concrete. Careful monitoring of the position of the slip form allows the hydraulic jacking system to control of the plumb of the finished concrete.The design of the slip form allows for any twisting to be countered.
Openings with varying wall thicknesses and cross-sections can be accommodated and all contribute to an acceptable lifting rate. The slip-form rig typically comprises three levels of working:
1) Upper reinforcement deck
The reinforcement deck is the uppermost deck on the slip-form rig and facilitates the fixing of the reinforcement. Some slip-form rigs combine the reinforcement deck with the middle working deck.
2) Working deck
The working deck is the main deck of the slip-form rig. Typically this deck will support the hydraulic jacking system and provides the working platform from which to place and compact concrete.It is important that the concrete is placed in even layers around the formwork shutters. The control of the concrete quality, supply and setting rate is vitally important for slip form operations.
3) Lower rubbing up deck
The rubbing up deck is located under the working deck and provides access to the faces of the poured concrete as they emerge from the underside of the shutters. The concrete is made good from this deck to provide a smooth surface finish.