Abstract
Cracks in cover of reinforced and pre-stressed concrete structures significantly influence the ingress of deleterious species causing decrease in durability of these structures. The paper is focused on the effect of fracture process on two selected physical parameters of concrete – the electrical resistivity and the ultrasonic pulse passing time – which might be employed as the quality indicator of concrete cover within (nondestructive) procedure(s) of assessment of the structural durability. The concrete electrical resistivity and ultrasonic passing time were investigated here with respect to two variants of treatment of the test specimens’ surface (the pre-dried surface and the wet surface). Test configuration of three-point bending of notched beam was utilized to control the crack propagation; the fracture process passed through several loading–unloading sequences between which the electrical resistivity and ultrasonic passing time readings over the fractured region were performed. Equivalent elastic crack model was used for estimation of the fracture advance (described via the effective crack length) at the loading stages corresponding to the resistivity and ultrasonic measurements. Relationships between changes of both the concrete resistivity and ultrasonic pulse passing time and the effective crack length is determined and discussed.
Highlights
AND MOTIVATIONThe paper is aimed at durability issues of reinforced and pre-stressed concrete civil engineering structures
Equivalent elastic crack model was used for estimation of the fracture advance at the loading stages corresponding to the resistivity and ultrasonic measurements
The paper presents results of sequential fracture tests rather uniquely complemented with nondestructive measurements allowing studying the effect of crack growth on the concrete electrical resistivity and ultrasonic pulse passing time
Summary
The paper is aimed at durability issues of reinforced and pre-stressed concrete civil engineering structures. The level of the material damage (the degree of decrease of the material structure’s integrity) in the cracked part of test specimens is investigated using ultrasound measurements; changes in electrical resistivity in that part can reveal relationship between the coefficient of diffusion of an aggressive agent (chloride) ions and the extent of the concrete fracture. Both these non-destructive methods are used here with the ambition to employ them for quick assessment of quality of concrete in the tensioned structural regions. Parts of the study devoted to either the electrical resistivity or ultrasonic measurements were already published by the authors in [13] and [14], respectively; this paper adds new results originating from supplementary tests conducted under different moisture conditions
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
