Calculating stress of external prestressing tendons

Abstract

This paper presents a simple method to calculate the increase in stress of the external prestressing tendons used to strengthen the concrete beams at any loading. First, the previous equations used to calculate stress of unbonded or external prestressing tendons are briefly reviewed, and then a new design method is proposed by considering deformation of the member. The steps of this method are simple and can be used for any loading. Experimental results obtained from several sources are compared with those calculated using the proposed method and the Harajli, Naaman et al., ACI-318 and BS 8110 code equations. The proposed equation showed good agreement and better accuracy.