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

Tests on prototype pretensioned natural stone beams

“…After release there is a transfer zone along which the strand's tensile force, and so the concrete's equilibrating compressive force, increases nonlinearly from zero at the ends to a peak at short distances inwards. Use of pullout and other tests to study the transfer zone mechanics is at the core of pretensioned concrete research [23][24][25][26][27][28][29].…”

Experimental study on the prestress loss of double‐end prestressing of carbon‐fiber reinforced polymer fabric for strengthening large‐diameter reinforced concrete circular columns

“…Prestressed CFRP fabric will inevitably exhibit prestress losses that reduce the strengthening effect of carbon fiber materials. [ 22–24 ] Therefore, it is important to study the prestress losses in CFRP fabric. Wang et al [ 25 ] developed a new type of prestressing anchorage device for CFRP fabric and tested the relaxation of CFRP fabric under axial tension.…”

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

“…CLS concrete with large elastic modulus is sensitive to the increase in concrete age, and the creep and shrinkage is more obvious than normal concrete [2]. When compared with long-term pre-stress loss [5][6][7][8], the instantaneous loss caused by friction also significantly affects the initial pre-stress force of the tendon [10][11][12][13][14][15]. The effective force inevitably decreases due to the friction loss between the pre-stressing tendon and duct [10].…”

“…Existing empirical formulas are employed to estimate pre-stress loss caused by elastic shortening, creep, shrinkage, friction, relaxation of the pre-stressed tendon and temperature [5][6][7][8][9]. Numerous factors influence the pre-stress loss of CLS concrete, including the type of cement, aggregates used, the mix of concrete, etc.…”