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

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

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This paper presents an experimental research work that evaluates the pre-stress loss caused by friction in crushed limestone sand (CLS) concrete members with post-tensioning.A total of 26 click here full-scale pre-stressed concrete beams were constructed and tested for the friction loss experiment.The considered variables mainly included the duct-forming materials, wires of tendons and arrangement of ducts.The tensile forces at both active and passive ends of specimen were recorded by steps, and then the pre-stress friction loss for each case was calculated.The result shows that the proportion of pre-stress friction loss in specimen with multi-wire tendons is in the range of 10–40%, with the trend first increasing before decreasing.

The pre-stress friction loss in specimen with curve duct accounts for 10–30%.The pressure on the curved part definitely increases the friction when compared with the straight duct.The pre-stress friction loss in specimen with rubber hose reaches nearly 40%, which is larger than the metal bellow and plastic bellow.The suggested values for each case are u11-200ps proposed for a deviation coefficient κ of 0.0017–0.

007 and a friction coefficient μ of 0.108–0.858.This can provide reliable theoretical support for the design and construction.