Multi-Energy CT - Nondestructive investigation of historic mortars

A wide variety of tools are available and are commonly used in the analysis of historical mortars and plasters, including but not limited to, acid digestion, thin section microscopy eventually combined with other imaging analytical methods, and the creation of historically accurate experimental mortars. The first two approaches produce reliable archaeometric data, but rely on invasive sampling and/or destruction of the sample. The latter method can be very informative about ancient techniques, but requires knowledge of the original mortar parameters. Typical X-ray Computed Tomography (CT) can be used to diagnose the condition of a plaster (e.g., locate cracks) but does a poor job of differentiating between the various compounds that make up a historical building material. This work describes a method by which Multi-Energy Computed Tomography (ME-CT) is used to provide archaeometric data on the mixing design comparable to the invasive and destructive methods.