Understanding global mechanical response of fiber reinforced cementitious composite beams from local fracture process

Abstract

Summary Cracking of the concrete structures is the major problem in the structural health and durability, and there is a critical need for continuous monitoring and assessing structural integrity. In order to monitor structures, traditional sensors are being used, which have some drawbacks, such only taking recording at specifically determined points. However, it has been shown that unless any existing damage is located at a point of high stress or has severely compromised the integrity of a structure, damages might be undetected. In order to have a more detailed understanding on the behavior of fiber‐reinforced concretes (FRC), their mechanical performance should be evaluated together with local fracture phenomena, such as crack propagation and localization. Because cracking is a major problem in the design and durability of structural elements. In this paper, propagation of cracks in FRC beams under 4‐point bending test is analyzed in detail with an image processing technique, Digital Image Correlation (DIC). DIC technique is applied to further identify fracture parameters such as crack width evolution and crack patterns at different stages of loading, which enables a detailed evaluation of the relationship between fracture parameters and resulting mechanical performance. Therefore, the main aim of this study is to enable the translation of global mechanical response of the FRC beams from the local fracture process, with a detailed characterization of cracks both experimentally and also with DIC analysis, which can be used for structural health monitoring of FRC beams, in terms early stage crack determination and crack monitoring through the lifetime.

Effect of interface roughness on fracture energy and fracture process zone of rock‐concrete specimens

“…Recently, the application of AE and DIC techniques has provided strong support for the study of cracking damage in quasi‐brittle materials 14–17 . The observation of the FPZ can be achieved by AE or DIC techniques 18–20 .…”

“…13 Recently, the application of AE and DIC techniques has provided strong support for the study of cracking damage in quasi-brittle materials. [14][15][16][17] The observation of the FPZ can be achieved by AE or DIC techniques. [18][19][20] When the crack extends at the rock-concrete interface, the localization of the interfacial strain at the crack tip forms a fracture process zone at the interface, leading to a nonlinear fracture behavior at the interface.…”

Novel percolation‐based measure for fiber efficacy in fiber‐reinforced concrete beams

“…In recent studies, the role of fiber orientation, distribution and pull‐out/torsional behavior on the transferred stress for enhancing the postcracking flexural strength was determined 9–11 as well as a size effect 12 . Additionally, image processing and tomography techniques have been applied to monitor the role of fibers as a nondestructive method 13–18 and the crack patterns have been estimated from surfaces of the specimen 19 …”