Influencia de las tensiones residuales en la relajación de los aceros de pretensado

Influence of residual stresses in the stress relaxation of prestressed concrete wires

This study demonstrates the influence of residual stresses in steel wires for prestressed concrete on the stress relaxation losses. Standard stress relaxation tests were performed on different types of wire, all with the same mechanical properties but with different residual stresses. Residual stresses we re measured by X-ray and neutron diff raction t e chniques and simulated by the finite element method. The experimental results show the importance of residual stresses on the stress relaxation. The role, sometimes controv e rsial, of initial pre-stretching, heat treatments and thermomechanical treatments on stress relaxation losses can also be understood in the light of the residual stresses induced during cold-drawing. Residual stresses must be taken into account for any correlation between mechanical properties and stress relaxation losses in the steel wires for prestressed concrete.