ABSTRACT
Precast concrete flooring offers an economic and versatile solution to ground and suspended floors in any type of building construction. Worldwide, approximately half of the floors used in commercial and domestic buildings, and more than three-fourths in car parks, are of precast concrete. Precast concrete engineers continued to optimise the cross section of the hollow core units leading to the so-called double-tee unit, achieving even greater spans and reduced mass compared with hollow core units. Each of the flooring systems introduced earlier has successively eroded the major advantages in the use of precast concrete floors over competitors such as timber or cast in situ floors. Standard edge profiles have evolved to ensure an adequate transfer of horizontal and vertical shear between adjacent units. The main function of the joint is to prevent relative displacements between units. The flexural behaviour of reinforced precast is certainly no different to cast in situ work, all other things being equal.
