A method for predicting prestress loss after cracking of concrete reinforcement

Abstract

The invention discloses a method for predicting the prestress loss after cracking of concrete reinforcement, which simulates the corrosion expansion cracking of concrete by adopting the thick wall thin cylinder theory, and calculates the corrosion expansion force in the cracking process based on the residual tensile stress of cracked concrete and the binding force of non-cracked concrete. The influence of steel strand corrosion on the adhesion between interfaces, concrete binding force and corrosion expansion force is analyzed, and the calculation formula of bond strength of steel strand corrosion is established. Considering the coupling effect of concrete cracking and bond strength degradation caused by corrosion and based on strain coordination and mechanical equilibrium equation, the calculation method of prestress loss of corroded pretensioned concrete members is established. The method for predicting the prestress loss after the concrete reinforcement is cracked can comprehensively consider the coupling effect of factors such as concrete cracking and bond degradation caused by corrosion, and has important guiding significance for the evaluation of the prestress loss of the existing pretensioned concrete beam bridges.

Description

technical field [0001] The invention relates to the technical field of prestress loss evaluation methods, in particular to a method for predicting prestress loss after cracking of concrete along bars. Background technique [0002] Prestressed concrete elements have long been considered to have good durability. However, due to design defects, poor construction and unfavorable erosion environment and other factors, the problem of performance degradation of prestressed concrete components has become increasingly significant. Corrosion of prestressed tendons is one of the main factors causing the degradation of structural durability. Corrosion will reduce the cross-sectional area of ​​prestressed tendons, cause concrete cracking, reduce bond strength, and cause loss of effective prestress. The effective prestress inside the concrete member is the key factor to ensure its normal use and safe service. [0003] The prestress loss of existing concrete components is related to many...

AI Technical Summary

Problems solved by technology

There is no report on the prestress loss of pre-tensioned concrete members after corrosion. How to reasonably evaluate the prestress loss inside the corroded pre-tensioned concrete members needs to be studied

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