Evaluation of structural cracking in concrete

Citation:

Zaborac, Jarrod , Apostolos Athanasiou, Salvatore Salamone, Oguzhan Bayrak, and Trevor Hrynyk. “Evaluation of structural cracking in concrete”, no. FHWA/TX-19/0-6919-1 (2019). https://rosap.ntl.bts.gov/view/dot/55742.

Abstract:

Current methods used to assess structural cracking in concrete bridge infrastructure consist of various rating criteria in the form of pre-established concrete crack width and crack density limits. While cracking data obtained from routine inspections can aid in identifying bridge degradation, typical inspection techniques provide limited insight regarding the severity of structural distress. Further, inspection evaluation criteria are almost always independent of member-specific design details. The primary objective of this project was to develop crack-based strength assessment procedures that employ visual concrete crack data as input (e.g., measured crack widths, crack inclinations, crack patterns, etc.) and provide quantitative output related to bridge member health. Focus was given to developing procedures that require easy-to-obtain bridge member cracking data and the execution of low-cost analyses that can be performed using basic, and readily-available, software (e.g., MS-Excel or similar). Two different crack-based assessment procedures for in-service concrete bridge members were developed: i) a cracked continuum shear strength assessment procedure that is rooted in concepts of reinforced concrete mechanics and is used to examine shear-related distress in concrete bridge members, and ii) crack pattern quantification procedures that employ fractal analysis techniques to perform image-based assessments of crack patterns for the purpose of gaining insight into bridge member health. Research findings confirmed that diagonal crack widths, on their own, do not serve as reliable indicators of concrete member shear distress; however, mechanical modeling techniques that incorporate crack related input parameters can be used to conduct meaningful structural assessments for shear cracked bridge members. Further, the experimentally-validated cracked continuum assessment procedure can be used to develop member-specific crack inspection field aids to be employed on-site for the assessment of diagonal cracking in reinforced concrete bent caps.

Notes:

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