Advancing Concrete Durability Research through X-ray Computed Tomography

Abstract

Radiation technology such as X-ray computed tomography (X-ray CT) is a powerful tool for materials research. Such non-destructive imaging technology allows us to visualize in three dimensions (3D) the internal structure of materials without damaging the specimen. This paper thus presents our studies on the application of microfocus X-ray CT, synchrotron radiation X-ray CT, and the integrated computed microtomography and X-ray diffraction (CT-XRD) method to advance cement and concrete research. CT images coupled with 3D image analyses allow us to identify and measure the air voids, pore scale microstructure and crack geometry. Image-based computational simulations provide us to estimate transport parameters such as diffusion tortuosity and water permeability in the digitized pore space. With the introduction of novel experimental techniques, deterioration or microstructure changes in hydrated cement systems, for example, attributed to calcium leaching, freeze-thaw cycles, elevated temperature, and steel reinforcement under tension are further elucidated. This review paper then ends with speculation of the future directions of concrete durability research via X-ray CT.