METHOD FOR PREDICTING PRE-STRESS LOSS AFTER CRACKING OF CONCRETE ALONG REBARS

摘要

Provided is a method for predicting pre-stress loss after the cracking of concrete along rebars, the method comprising: simulating the cracking of concrete due to corrosion expansion based on the thick-walled thin cylinder theory, and calculating the corrosion expansion force during cracking based on the residual tensile stress of the cracked concrete and the constraining force of the uncracked concrete; analyzing the influence of the corrosion of a steel strand on the adhesion force between interfaces, the concrete constraining force, the corrosion expansion force and other factors, and building an expression for calculating the bonding strength of the corroded steel strand; and after comprehensively considering of the coupling effect of factors such as concrete cracking and bond strength degradation caused by corrosion, establishing a method for calculating the pre-stress loss of a corroded pre-tensioned concrete member based on a strain coordination and force balance equation. The method for predicting pre-stress loss after the cracking of concrete along rebars provided by the present invention can comprehensively consider the coupling effect of factors such as concrete cracking and bond strength degradation caused by corrosion, and this has an important guiding significance for the evaluation of pre-stress loss of existing pre-tensioned concrete beam bridges.