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Mapping Drying Shrinkage Deformations in Cement-Based Materials.


pdf icon Mapping Drying Shrinkage Deformations in Cement-Based Materials. (704 K)
Neubauer, C. M.; Jennings, H. M.; Garboczi, E. J.

Cement and Concrete Research, Vol. 27, No. 10, 1603-1612, 1997.

Keywords:

cements; deformation; digital images; finite elements; shrinkage; mapping

Abstract:

A new technique for mapping the deformations in a digital image of microstructure is presented. This technique works on any set of two digital images of the same area taken before and after deformations are generated. Results for cement paste show that the deformations are distributed as large compactions separated by crack-like rarefactions. The rarefactions may represent the precursor to microcracking. The results suggest that macro-scale deformation is the result of a competition between expanding and contracting parts of the matrix. Individual microdeformations can then be much higher in magnitude than average macrodeformations. A single shrinkage value like the average macrodeformation does not, therefore, adequately represent the microstructural processes occurring during drying shrinkage.