Prestress losses evaluation in prestressed concrete prismatic specimens

Abstract

This paper presents an experimental research work to evaluate prestress losses in pretensioned 12 prestressed concrete. An experimental program including variables such as concrete mix 13 design, specimen cross-section size and concrete age at the prestress transfer was carried out. 14 Several pretensioned prestressed concrete prismatic specimens were made and tested using 15 the ECADA+ test method, based on measuring prestressing reinforcement force. In addition, 16 specimens were instrumented to obtain the longitudinal concrete strains profiles at any time. 17Measurements from both techniques were taken over one year. Measured prestress losses 18 included elastic shortening losses and time-dependent losses due to concrete shrinkage and 19 creep. A coefficient to account for the relationship between the prestress losses from the 20 measured prestressing forces and the actual prestress losses from concrete compressive strains 21 is proposed. The experimental results were compared with the predicted prestress losses using 22 methods from several codes. 23 Keywords 24Concrete, pretensioned, prestress loss, creep, shrinkage, transfer, strain 25 26 2

Composite beam theory for pretensioned concrete structures with solutions to transfer length and immediate prestress losses

“…Bymaster et al [89] studied prestress losses of light weight self-consolidating concrete and reported that current AASHTO design provisions [52] may overestimate elastic shortening loss for specimens with low concrete strength. Caro et al [90] and Garber et al [91] summarized the major prestress losses formulas and developed a database for pretensioned concrete structures.…”

Effect of Prestress Levels and Jacking Methods on Friction Losses in Curved Prestressed Tendons

“…Furthermore, almost all of the test specimens used in the previous studies were limited to small-scale concrete members [7][8][9]. There are a few reports on friction loss tests using full-scale concrete girders.…”

Experimental Analysis on Pre-Stress Friction Loss of Crushed Limestone Sand Concrete Beams

“…Nowadays, extensive laboratory tests on pre-stress friction loss have been carried out. The Anchorage-Measurement-Access (AMA) system is the main experimental idea proposed for estimating the pre-stress friction loss [16]. Two full-scale pre-stressed concrete girders were constructed [17] and the influence at various pre-stress levels was discussed.…”