3D visualisation of pore structures in cement-based materials by LSCM

Abstract

The visualisation and representation of three-dimensional (3D) pore morphologies in cement-based materials are of significant interest for understanding the relationship between pore structures and durability. In this study, laser scanning confocal microscopy (LSCM) was used to observe a series of two-dimensional (2D) cross-sectional images. Thresholding was used as the image segmentation technique to group the image pixels by checking the pixel intensities against a set of thresholds. 3D models of the pore structures and the matrix were reconstructed by grey-level interpolation, which transformed the 2D cross-sectional images into 3D models. The experimental results show that the 3D complex morphologic characters of pore structures and the matrix can be accurately visualised with the image segmentation technique and grey-level interpolation.

Geometrical model for tortuosity of transport paths in hardened cement pastes

“…In cement-based materials such as mortar and concrete, hydrated cement pastes are the principal binder phases and their microstructures influence the transport behaviours of cement-based materials (Bentz et al, 2000;Quenard et al, 1998). In particular, pore structure plays a critical role in analysing transport behaviour and interactions with the environments that influence material durability (Beaudoin et al, 1994;Zhang et al, 2010). Establishing a correlation between transport behaviour and pore structure is thus necessary to evaluate and predict the performance of concrete over the lifetime of a structure, which can be a minimum of several decades and, increasingly often, over a century for very important structures.…”

Background-Free Deep Fluorescent Imaging of a Pore Architecture in Geomaterials Based on Magnetic Upconversion Nanoprobes

“…In LSCM imaging, the vertical depth of the optical section is in excess of 30 μm, and it can even reach ∼150 μm in some quartz sandstones. A bunch of geological materials such as sandstone, carbonates, − mudstones (shales), marble, and even many engineering materials such as polymer membrane, concretes, , and catalysts have been visualized by LSCM. Additionally, many geological applications, including fluid transport in geological materials and brittle failure processes as well as stress-induced damage in rocks, have been studied based on the LSCM imaging data of the pore architecture.…”

Editorial

“…We can improve the processing of cement at the clinkering stage by a better scientific understanding of the action of grinding aids (Assaad et al, 2010). We can also modify the properties of cement matrices in a number of ways: by controlling dimensional stability (Li et al, 2010), by adding fibres which strengthen the cement matrix (Park et al, 2010) and by achieving a better understanding of the pore structures in hardened cement (Zhang et al, 2010).…”