Effects of Increasing Concrete Strength on the Dimension of Beams

Abstract

A theoretical study was carried out to investigate the effects of increasing concrete strength on the depth of rectangular beams. Two series of beams were investigated. Th first series comprised reinforced concrete beams with spans from 6 to 15 m, and the second comprised prestress concrete beams with spans from 12 to 30 m. The concrete strength ranged from 20 to 120 MPa and from 30 to 120 MPa for the reinforced and prestressed concrete beams, respectively. The results show that for rectangular concrete beams, an increase in concrete strength results in a rather significant reduction in the beam depth, whereas for rectangular prestressed concrete beams no significant reduction in the beam depth is gained from increasing the concrete strength because the deflection governs the design.