Transmission length formulations for prestressed concrete elements

The determination of correct transmission length is one of the most important features when designing pretensioned concrete elements. Transmission length should be calculated to verify the adequacy of prestressing force in the cable over its length, providing an adequate distance outside the transmission length for sections with high bending moment values. Moreover, shear resis- tance of sections included in the transmission length has also to be calculated considering reductive factors. Here a database of ex- perimental values has been used to assess some current formulations, obtaining in some cases contrasting transmission length esti- mations. A statistical analysis has been also performed in order to identify the effect of the main variables influencing transmission length. Lastly, a new formulation, in a complete and simplified version, has been proposed, and its accuracy has been assessed by means of suitable statistical indicators.