FLEXURAL STRENGTH OF PROFILED BEAMS

A construction technique that uses steel decking as permanent and integral shuttering for the sides and soffits of reinforced concrete beams is described. Experimental tests on large-scale profiled beams have shown that the side steel decking can substantially increase both the flexural strength and the ductility, as well as the shear strength of the beam. Furthermore, previous theoretical research has shown that the side steel decking can substantially reduce deflections due to creep and shrinkage and allow increases in span/depth ratios of about 20%. However, the behavior of this form of composite construction can be affected by local buckling of the steel decking and the strength of the shear bond at the interface between the decking and concrete. Simple design procedures are developed to prevent local buckling of the steel decking before the ultimate strength of the beam is reached, and to determine the flexural strength of the profiled beam for various strengths of the shear bond.