Abstract
The study of deformation and fracturing properties of concrete is essential to understand failure mechanisms of concrete material, especially under extreme and complex loading conditions, e.g. high strain rates and multiple confinements. In this study, dynamic deformation and fracturing behaviour of ordinary concrete under biaxial confinements are investigated by using a triaxial Hopkinson bar system, three-dimensional digital image correlation, and synchrotron X-ray computed tomography techniques. Results show that compressive strain localisation areas appear around aggregates due to the elastic difference between aggregate and matrix, where accompanied with initiation of interfacial cracks and propagation of main cracks. Transgranular cracks can also be observed in the central of specimen in CT slices due to the effect of strain concentration. In addition, CT slices with distinct properties in various directions indicate the anisotropic fracturing behaviour of concrete due to the effect of biaxial confinements.
Highlights
Concrete structures under biaxial stress states are likely to suffer dynamic loads such as earthquake, impact, and blast in the service. Under these extreme loading conditions, concrete materials are more prone to deterioration and failure, with deformation and fractures significantly different from what has been observed under quasi-static conditions
The dynamic deformation and fracture properties of ordinary concrete under biaxial confinements have been studied by triaxial Hopkinson bar (Tri-HB) system, 3D-digital image correlation (DIC) and X-ray computed tomography (CT) techniques, and further verified by simplified matrix-inclusion sample
The results show that compressive strain localization will appear around aggregate during dynamic loadings due to the elastic mismatch and interfacial cracks will initiate firstly so that main cracks are more prone to propagate
Summary
Concrete structures (e.g. tunnel linings, column-beam joints, and nuclear safety shells) under biaxial stress states are likely to suffer dynamic loads such as earthquake, impact, and blast in the service. Under these extreme loading conditions, concrete materials are more prone to deterioration and failure, with deformation and fractures significantly different from what has been observed under quasi-static conditions. The Tri-HB system could achieve the measurement of lateral stress wave histories during dynamic loadings [4, 5], which has been validated and replicated by numerical modelling [6]. The Tri-HB system, 3D-DIC and synchrotron CT techniques were applied to achieve the measurement of mechanical and fracturing properties
Sign-in/Register to view highlights & summary 
Published Version (
Free)
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 call