De la necesidad de mejorar el ensayo normalizado de adherencia en estructuras pretensadas de armadura pretesa

The need to enhance the standard test to determine bond properties of pretensioned concrete structures

Bond between concrete and prestressing strand is essential to guarantee the correct structural behavior of the pretensioned concrete elements. At present Spanish Standard EHE (1998) establishes that transfer length and development length must be determined experimentally. However there is not a standard procedure to measure bond performance along the development length. In this article the basis of a new standard and economic test is discussed, which allows determination of bond properties of prestressing strand. A critical review of the different existing experimental procedures is done. Finally the general characteristics of a future standard test are established, in order to characterize bond properties along both transfer length and flexural bond length of pretensioned concrete elements.