scholarly journals Size Effect on Behavior of Critical Shear Crack in Reinforced Concrete Beam using Digital Image Correlation

2016 ◽  
Author(s):  
Ahmed Belbachir ◽  
Syed Yasir Alam ◽  
Mohammed Matallah ◽  
Ahmed Loukili

2006 ◽  
Vol 33 (11) ◽  
pp. 1418-1425 ◽  
Author(s):  
Michel Küntz ◽  
Marc Jolin ◽  
Josée Bastien ◽  
Fabien Perez ◽  
François Hild

A displacement-measuring technique using digital image cross-correlation was applied to study the in situ behavior of a shear crack in a reinforced concrete beam during a bridge static load test. A numerical approach allowed measurement of the displacement field at the location of the crack on a 110 mm × 130 mm surface with a resolution of the order of 10 µm. Results of the analysis indicate that crack loading varies significantly with load position and sequence of applications to the structure. These results further indicate that damage cannot be attributed to the repetition of a single load cycle, as is often the case. The findings should improve the understanding of the fatigue behavior of reinforced concrete structures under operating conditions.Key words: displacement field, crack opening displacement, digital image correlation, static loading test, fatigue, durability, reinforced concrete, monitoring.





2019 ◽  
Vol 97 ◽  
pp. 03008 ◽  
Author(s):  
Dorota Marcinczak ◽  
Tomasz Trapko

The article presents tests of a reinforced concrete beam strengthened in a shear with PBO-FRCM composite materials. Measurement of the deformation of the composite was carried out using two methods - with strain gauges and the optical DIC method (Digital Image Correlation). The DIC method consists in taking a series of photographs of the tested object before and during loading. The surface of the tested element must have randomly spaced spots that are applied to the object before measurement. During the study, the cameras monitor the shifting of spots against each other, which in comparison to the reference image before loading gives information about strains and stresses of the tested element. Measurements of deformation of composite materials using strain gauges are difficult to clearly analyse, because the strain gauge is in a specific, limited place, which does not correspond to the work of the entire composite. In addition, the strain gauge tends to break at the place of crack. The article discusses this problem by presenting the results of deformation of PBO-FRCM composite meshes measured in two mentioned ways, their comparison and discussion of results.



BUILDER ◽  
2019 ◽  
Vol 259 (2) ◽  
pp. 66-68
Author(s):  
Dorota Marcińczak

DIC (DIGITAL IMAGE CORRELATION) METHOD IN THE RESEARCH OF RC BEAMS STRENGTHENED WITH PBOFRCM MATERIALS. The article presents tests of a reinforced concrete beam strengthened in a shear with PBO-FRCM composite materials. Measurement of the deformation of the composite was carried out using two methods - with strain gauges and the optical DIC method (Digital Image Correlation). The DIC method consists in taking a series of photographs of the tested object before and during loading. The surface of the tested element must have randomly spaced spots that are applied to the object before measurement. During the study, the cameras monitor the shifting of spots against each other, which in comparison to the reference image before loading gives information about strains and stresses of the tested element. Measurements of deformation of composite materials using strain gauges are difficult to clearly analyze, because the strain gauge is in a specific, limited place, which does not correspond to the work of the entire composite. In addition, the strain gauge tends to break at the place of crack. The article discusses this problem by presenting the results of deformation of PBO-FRCM composite meshes measured in two mentioned ways, their comparison and discussion of results.



2021 ◽  
Vol 6 (7) ◽  
pp. 99
Author(s):  
Christian Overgaard Christensen ◽  
Jacob Wittrup Schmidt ◽  
Philip Skov Halding ◽  
Medha Kapoor ◽  
Per Goltermann

In proof-loading of concrete slab bridges, advanced monitoring methods are required for identification of stop criteria. In this study, Two-Dimensional Digital Image Correlation (2D DIC) is investigated as one of the governing measurement methods for crack detection and evaluation. The investigations are deemed to provide valuable information about DIC capabilities under different environmental conditions and to evaluate the capabilities in relation to stop criterion verifications. Three Overturned T-beam (OT) Reinforced Concrete (RC) slabs are used for the assessment. Of these, two are in situ strips (0.55 × 3.6 × 9.0 m) cut from a full-scale OT-slab bridge with a span of 9 m and one is a downscaled slab tested under laboratory conditions (0.37 × 1.7 × 8.4 m). The 2D DIC results includes full-field plots, investigation of the time of crack detection and monitoring of crack widths. Grey-level transformation was used for the in situ tests to ensure sufficient readability and results comparable to the laboratory test. Crack initiation for the laboratory test (with speckle pattern) and in situ tests (plain concrete surface) were detected at intervals of approximately 0.1 mm to 0.3 mm and 0.2 mm to 0.3 mm, respectively. Consequently, the paper evaluates a more qualitative approach to DIC test results, where crack indications and crack detection can be used as a stop criterion. It was furthermore identified that crack initiation was reached at high load levels, implying the importance of a target load.



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