Arco NDC, Hull, UK

Working closely with the main contractor, Twintec installed a 360mm thick, pile-supported, structural slab. The slab contains over 7,350m³ of C50 grade concrete and 650 tonnes of special designed mesh fabric. The majority of internal joints are tied construction joints meaning that the slab acts as a single uniform mass and shrinkage movement is distributed evenly throughout the slab and around the perimeter. This design allows the client complete flexibility over the position of internal fitout items - racking and storage systems - thus providing a real long-term benefit to the client.

The warehouse slab consists of both free movement areas cast to achieve FM2 flatness tolerance of TR34 4th Edition and also a 78m deep VNA racking area cast to DM2 flatness tolerances of TR34 4th Edition. The DM2 tolerance was achieved over 98.5% of the total aisle length (around 1,750m) and the specialist techniques employed by Twintec mean that there are no joints of any kind within the operating aisles (in fact, the VNA area was also checked against FM1 flatness tolerance - as a matter of interest - and found to pass this comfortably). To achieve this level of flatness on a slab of this thickness in a single pass and at an output rate of around 1,000m² per day is truly exceptional and a credit to the highly skilled Twintec construction team and the proactive and supportive approach of the main contractor.

One other area of interest in the construction is at the junction between the existing and new buildings. The joint where an old and a new slab meet each other in this type of project is always an area of concern for an end user. To help with this specific situation Twintec have developed their Twinflex 'invisible' joint system. Twinflex is a jointing system that uses high quality specialist resins to remove the 'visible' joint between the floor slabs and provides a smooth, long-lasting, aesthetically pleasing transition from old to new. Unlike other systems there is no joint 'line' or opening joint with this system so clients can have confidence that their MHE will operate smoothly and efficiently for years to come across the transition.

Although Twintec are predominantly experts in constructing large bay, steel fibre reinforced floor slabs, this project demonstrates that Twintec's skills are not limited to steel fibre only and they can be trusted to deliver a client's requirement whatever the chosen system.

Find out more about Twintec's total offer concept Design - Build - Guarantee