Abstract
Pretensioned concrete members are designed and manufactured by using at least two
materials: concrete and prestressing reinforcement. Also, two main stages must be considered:
prestress transfer and member loading. Hence, the behavior of these members
depends strongly on the reinforcement-to-concrete bond performance and prestress
losses. In this paper, a testing technique to measure the specific parameters related with
the involved phenomena is presented. The testing technique is based on the analysis of series
of specimens varying in embedment length to simulate several cross sections at only
one end of a pretensioned concrete member. Each specimen is characterized by means
of the sequential release of the prestress transfer (detensioning) and the pull-out (loading)
operation. The test provides data on prestressing force, transmission length (initial and
long-term), anchorage length (without and with slip), reinforcement slips, bond stresses,
longitudinal concrete strains, concrete modulus of elasticity, and prestress losses (instantaneous
and time-dependent).
