Invisible Connections has recently completed a comparison study of Reinforcement Continuity Strip.
On every credible UK project, concrete reinforcement is specified (to BS4449:2005+A3:2016) and required to be CARES approved. ‘Cut and bent’ requirements are designed to a range of shape codes (BS8666:2005 refers). These shape codes are the basis for designers to define all dimensions, uniquely to the needs of the project.
After careful quantification (avoiding wastage) the reinforcement is fabricated to order by CARES approved fabricators, bundled and uniquely labelled to suit, then delivered in sync with the site programme. This process is accepted and adopted as good standard practice, ensuring that design intent is satisfied, whilst meeting the practicalities of construction and the quality assurance needs of professional stakeholders.
The rationale described above also applies to threaded couplers. However, when it comes to reinforcement continuity strip (where the reinforcement is uniquely subjected to the additional demands of rebending on site), it can often appear – somewhat inexplicably – as if ‘anything goes.’
Using reinforcement continuity strip shouldn’t significantly compromise reinforcement design, yet it often does. UK CARES approved continuity strip manufacturers are adept at the timely fabrication of their products, to accommodate principal design and construction practicalities. Nonetheless, there is widespread use of continuity strip brought into the UK, often without any recognisable form of approval, and treated by some as if an insignificant ‘accessory’.
Such products tend to be entirely ‘standard’ in their configuration (with a ‘one size fits all’ approach to anchorage, lap and casing length). They offer little to address the needs of reinforcement design and often prove wasteful in application. Varying the reinforcement and casing dimensions to suit, results in what we know as ‘specials’. For UK CARES approved fabricators, these simply incorporated variations help to ensure that design intent is met, whilst also making life much easier for contractors.
The report looks at the argument for ‘specials’ to achieve the required reinforcement design, and clarifies why reinforcement continuity strips are important structural components that require performance validation. It also demonstrates why over 90% of FERBOX reinforcement continuity strip is made-to-measure, providing many efficiency advantages for concrete frame construction.
Derek Brown, Managing Director of Invisible Connections, said:
‘I’ve been heavily associated with continuity strip for over 30 years as a specialist manufacturer. Experience has taught me that what’s asked for isn’t always the same as what’s needed. With minimal upfront consideration and dialogue, we deliver value and efficiency to our customers by offering tailored solutions – providing correct construction details, whilst driving out wastage.’
View the full report, here.
We hadn’t typically gone the ‘specials’ route before. But, by investing a little upfront time to schedule our FERBOX requirements, we gained a smooth supply and installation process - without wastage or complication - and exceeded the programme demands of our slip-formed cores.