Fiber-reinforced concretes (FRCs) offer significant improvements in tensile strength and durability compared to most other concrete mixes. However, for safe and efficient use of FRC in large...

This paper describes a novel methodology for quantitative in-situ moisture measurement without tracking agents using X-ray computed tomography (XCT). The high levels of greyscale precision required for the measurement of moisture without tracking agents resulted in the need for an additional image calibration procedure to correct for water-related X-ray scattering and for equipment-variability-related artefacts arising during in-situ testing. This calibration procedure was developed on the basis of existing principles of XCT image correction. Resulting images of moisture distribution exhibit a high level of agreement with expected material behaviour. This research demonstrated that XCT can be successfully used to measure both moisture front movement over time and changes in 3D moisture distribution within samples. This approach to moisture measurement lays the groundwork for the planned future investigation of the interaction between cracking induced by varying chemical and mechanical processes and water transport in concrete.

To make significant advances in concrete engineering, it will be necessary to understand the behavior of cementitious materials at the microscale. To achieve this goal, the nature of damage initiation and growth needs to be understood at very small scales. This research program sought to increase that understanding through the collection of microscale data using X-ray computed tomography (CT). The tensile and compression behavior of both ultra-high performance concrete (UHPC) and conventional concrete were investigated as a part of this program. Relationships were identified between mechanical performance parameters, such as stiffness degradation and work of load, and cracking parameters, such as crack volume and crack surface area, that could be quantified mathematically and implemented into future finite element analysis (FEA) models. The results of this research program have the potential to improve the accuracy and resiliency of numerical models and to provide insight to the materials engineer...