Observation of flexural cracks in loaded concrete beams using MRI

Abstract

This paper describes apparatus that enables loading of a concrete beam reinforced with aramid fibre-reinforced plastic (AFRP) inside the magnet of a magnetic resonance imaging (MRI) scanner, and the subsequent measurement in three dimensions of the propagation of fractures within the concrete. These are then correlated with the internal structure of the concrete which had been previously determined by scanning the beam soon after casting. The particular requirements of the test frame for use within the scanner and the methods used to satisfy them are described in detail, as is the test procedure. It is shown that the resultant images can be visualised either as twodimensional (2-D) slices, or as 3-D data sets; the images can also be post-processed to highlight the particular feature of interest.

Experimental and numerical analysis of strain gradient in tensile concrete prisms reinforced with multiple bars

“…In addition, the digital image correlation (DIC) technique is becoming an increasingly useful tool for tracking deformations at the concrete surface [16]. Modern image back-scattering techniques, such as X-ray [17], acoustic emission tomography [18], and magnetic resonance imaging [19], are available as indirect means of deformation measurement. However, the interpretation of data obtained from these non-contact methods is often complicated and may require users' judgement, and they are limited to simple specimen geometry and loading cases.…”

Effects of Bar Reinforcement Arrangement on Deformations and Cracking of Concrete Elements

“…The digital image correlation (DIC) technique is becoming an increasingly useful tool for tracking deformations at the concrete surface (Michou et al 2015). The modern image back-scattering techniques (X-ray (Landis & Bolander 2009), acoustic emission tomography (Cheng et al 2015), or magnetic resonance imaging (Marfisi et al 2005)), however, are limited to simple specimen geometry and loading cases. Thus, the internal deformations of the concrete can be assessed only in an averaged manner.…”

Centriškai tempiamųjų armuoto betono elementų įtempių ir deformacijų būvio analizė

“…Lazeriniai deformacijų matuokliai (Zhu et al 2012) arba skaitmeninių vaizdų koreliacijos, angl. digital image correlation DIC, metodika taikomi bandinio paviršiaus deformacijoms nustatyti, tačiau betono vidines deformacijas galima vertinti tik apytiksliai, nes šiuolaikinių vaizdinės medžiagos apdorojimo būdų, tokių kaip optiniai jutikliai (Li et al 2004), rentgeno spinduliai (Landis & Bolander 2009), akustinių spindulių tomografija (Cheng et al 2015) arba magnetinio rezonanso tomografija (Marfisi et al 2005), taikymas ribojamas mažais bandinių dydžiais ir paprasčiausiais apkrovimo atvejais.…”