Investigation of Drying Shrinkage of Cement-Based Materials Assisted by Digital Image Correlation

This paper presents a validation of a new protocol for the characterization of drying shrinkage of cement paste. The method consists of using environmental scanning electronic microscope (ESEM) or climatic chamber (CC) assisted by digital image correlation (DIC) to study the drying shrinkage of cement-based materials. The final motivation is to study the influence of the drying rate on cement-based materials' delayed strain at the microscopic scale. Hence, the impact of specimen shape, size, and the imposed relative humidity history on the drying shrinkage is studied. Results show that for a given material, the amplitude of drying shrinkage is independent of the rate of drying and the specimen shape. Advantage was taken of the two techniques proposed in this paper to perform drying length change measurement both in ESEM and CC. (authors)