Study of Moment Redistribution in Prestressed Concrete Beams

This paper describes an investigation into the redistribution of moments in certain composite concrete beams. Seven two-span beams 6.2 m long were constructed and tested by means of applying two point loads at midspans. Each beam comprised two precast beams made continuous by a top flange cast “in situ.” Since the term “redistribution of moments” is normally used in two different meanings (in research papers or in codes of practice), the concept of degree of redistribution is explained. A brief bibliography review presents the main research advances in this subject, and the contradiction between the results is significant in some cases. The experimental program is presented as well as the geometric and material properties of the test beams. The main results obtained from tests are presented from zero loading up to failure. The ultimate loads obtained from the tests are compared with theoretical ones considering both plastic and elastic behavior. Conclusions from the results are presented.