Research On Apparent Morphology And Constitutive Characteristics Of Corroded Reinforcement

Steel corrosion is the main reason for the performance deterioration of reinforced concrete structures. Compared with the intact reinforcement, the apparent morphology of corroded steel bars is not uniform and uncertain, and the basic mechanical properties are also showing decay trend.This paper which is based on model test and numerical simulation of reinforcement corrosion studied the spatial distribution and probability distribution characteristic of corroded reinforced morphology and tensile constitutive relation. The main work and results were as follows:(1)Compared the effectiveness of the vernier caliper method, displacement method, 3D scanning method and XCT to testing the corroded reinforced apparent morphology. The results show that 3D scanning method is the most effective way.Relative to conventional calipermethod and drainage method and so on, it not only has better testing precision and efficiency, but also greatly expand the testing index categories. With respect to the high-precision XCT method, the 3D scanning test cost is much lower and higher efficiency. At the same time the specimen size requirements is also lower. Besides, the test results are also maintained a good consistency.(2)Based on the analysis of the apparent morphology characteristics of corroded steel bars, this paper using the 3D scanning method and MATLAB made a post processing program. On this foundation, the morphological characteristics of corroded reinforcement bar which is in the concrete and the simulated pore solution was researched; Extracted a variety of spatialdistribution and probability distribution characteristics of corrosion parameters.Beside, established maximum corroded corrosion depth, minimum cross section area, maximum cross section eccentricity and smallest section moment of inertia and the correlation between steel corrosion rate and other parameter(3)In order to studying the corrosion condition and the corrosion degree how to affect the tensile reinforcement constitutive, different types of corrosion of reinforcing bar tension test was done. Combined with 3D scanning method, identified the corroded reinforced minimum residual cross-sectional area, minimum moment of inertia of cross section, and the maximum eccentricity from the axis of the section to coordinate and tensile yield gap section coordinates.In addition to that, analyzes the statistical rule of distance index.(4)Based on 3D scan data, established the constitutive model of corroded reinforced with finite element method. Through processing the steel corrosion data model entities, establish the finite element model of corroded reinforced. By using the model of corroded reinforcement tensile simulation analysis, the results obtained are in good agreement with the experimental curve constitutive relations. and this study provides a new way of practical value for the study of the constitutive relationship of corroded steel bars.