this study investigates propagation of mode i crack in b70 pre-stressed concrete sleepers by fracture mechanics approach. a new experimental analysis is done for notched b70 pre-stressed concrete sleepers with replica test and image analysis. a scanning electron microscope test (sem) and an image analysis are applied for the replica test in order to determine crack length and crack mouth openin...

The life of a structure can be extended by early detection of cracks with appropriate repairs. In reality, structural failure is always accompanied by the formation of cracks and early detection of cracks is essential in extending structure life and preventing structural failure(1). Therefore, there is a huge amount of research on monitoring surface crack development in concrete structures, esp...

OBJECTIVES Validation of choroidal thickness and other biometrics measured by spectral domain optical coherence tomography (SD-OCT) in predicting lacquer cracks formation in highly myopic eyes. METHODS Patients with a refractive error worse than -8 diopters and moderate myopic maculopathy were recruited into two groups based on the presence or absence of lacquer cracks (36 eyes without and 33...

This paper explores the usage of microfocus X-ray computed tomography (CT) for visualization and quantification of diffusion phenomena in cracked concrete. Mortar specimens of varying shapes (prismatic and cylindrical), crack types (artificial and splitting tensile), and binder compositions (OPC and fly ash) were prepared. Cesium carbonate (Cs2CO3) was used as a tracer in the diffusion test bec...

Abstract: High-strength steel has increasingly become widely used among various engineering practices, but the relevant provisions of the codes lag behind its development. Six sets of experiments on simple supported beams reinforced with HTB600 and HTB700 rebars subject to bending loading were conducted in this study to 1) investigate the conditions of crack development, 2) contrast the calcula...

Cracking is one of the most severe problems facing the concrete industry worldwide. Of critical importance is the drastic decline of durability associated with these cracks, and the resulting cost of repair or replacement of concrete structures. This research examines the effect of crack width and crack frequency upon the durability of reinforced mortar, quantified by water permeability. Crack ...

Image processing technologies are proposed to quantify crack patterns. On the basis of the technologies, a software “Crack Image Analysis System” (CIAS) has been developed. An image of soil crack network is used as an example to illustrate the image processing technologies and the operations of the CIAS. The quantification of the crack image involves the following three steps: image segmentatio...

We report a novel mode of quasi-static oscillatory crack propagation when a cutting tool is driven through a thin polymer film [6,7]. In our experiments, for tools with a large enough width, the crack tip follows a highly periodic path, leaving behind a striking oscillatory pattern. Taking into account the separation of the film's bending and stretching energies and using classical fracture the...

15. Supplementary Notes Project performed in cooperation with the Texas Department of Transportation and the Federal Highway Administration. Project Title: Implementation of Automated Pavement Distress Rating Systems 16. Abstract This paper presents the image-processing algorithm customized for high-speed, real-time inspection of pavement cracking. In the algorithm, a pavement image is divided ...

We describe experiments on the dynamic fracture of the brittle plastic, PMMA. The results suggest a view of the fracture process that is based on the existence and subsequent evolution of an instability, which causes a single crack to become unstable to frustrated microscopic branching events. We demonstrate that a number of long-standing questions in the dynamic fracture of amorphous, brittle ...