Material characterization for cement-based materialsBy University of Eastern Finland & Imperial
How does the material charactization works?
Two tomographic imaging modalities were applied to imaging fluid flow/reactions in cement-based materials: electrical capacitance tomography (ECT) and x-ray CT. ECT uses electrical capacitance measurements from the surface of a specimen, to image the 3D electrical permittivity distribution within the specimen. A sequence of 3D permittivities, in turn, gives information on the flow of moisture — and enables inferring the moisture transport properties of the material. While ECT is a modality with low spatial resolution, x-ray CT provides high resolution information on the fluid flow. Another interesting phenomenon observed with x-ray CT in this project is the formation of a carbonated shell inside cement-paste in an experiment, where CO2 was injected to a specimen.
What is the purpose of the technology?
Because the ability of a cement-based material to impede the flow of moisture is directly linked to the durability of the structure, it is important to be able to characterize the moisture transport properties of those materials. The developed techniques, electrical tomography and x-ray CT, enable monitoring of moisture flow, as well as certain other related flow and reaction phenomena in cement-based materials. The information provided byt the tomographic modalities can be used for characterization of cement-based materials used in geo-energy operations.
Video: x-ray CT reconstructions
Electrical capacitance tomography imaging of moisture flows in cement-based materials was tested in UEF laboratory.
X-ray imaging cement-based materials was tested in ICL laboratory.