D. LENCZNER and P. DAVIS University of Wales Institute of Science and Technology

This paper discusses the loss of prestress in members which have been previously prestressed for some length of time and have subsequently been post-tensioned to a higher stress level. Such a situation may arise in alterations to a structure where advantage is taken of the higher allowable working stresses given in the latest code. The paper compares the subsequent creep and loss of prestress in post-tensioned brick members with their behaviour under the initial loading.