ULTIMATE STRENGTH OF CONTINUOUS PRESTRESSED CONCRETE BEAMS

Abstract

The object of the investigation is to study the ultimate strength of continuous prestressed concrete beams and the moment redistribution beyond the elastic limit. The effect of linear transformation of cable in continuous beams at ultimate load is also studied. Three continuous beams of two spans each are tested for this purpose. The effective depth at middle support section is maximum in beam B3, minimum in beam B2 and an intermediate value in beam BI . Stress - strain curve of concrete, as given by International Code of practice has been assumed to study moment-curvature relationship for beam BI . Also the distribution of moment in the beam at various loadings is calculated theoretically and verified experimentalLy. By the tests conducted on continuous prestressed concrete beams, it is concluded that 60 % of .redistribution of moments takes place and the ultimate load is invariant under a linear transformation of the cable.