Hollowcore slabs derive their name from the voids or cores which run through the units. The cores can function as service ducts and significantly reduce the self-weight of the slabs, maximising structural efficiency. The cores also have a benefit in sustainability terms in reducing the volume of material used. Units are generally available in standard 1200mm widths and in depths from 110mm to 400mm. There is total freedom in length of units, and splays and notches can readily be accommodated.
Hollowcore slabs have excellent span capabilities, achieving a capacity of 2.5 kN/m2 over a 16m span. The long-span capability is ideal for offices, retail or car park developments. Units are installed with or without a structural screed, depending on requirements. Slabs arrive on-site with a smooth pre-finished soffit. In car parks and other open structures, pre-finished soffits offer a maintenance-free solution.
Prestressed units will have an upward camber dependent upon the span, level of prestress, etc. This will be reduced when screeds/toppings or other dead loads are applied.