On the basis of a proposed theoretical approach for the analysis of X-ray diffraction spectra, the morphology, deformation, stress and dislocation configurations in hydroxide crystallites of the interfacial transition zone in high-strength concrete (water/cement ratio of about 0.35) were investigated. It was determined that (00▪1) dislocation slip planes divided the crystallites into coherent domains and arranged quasi-periodically along the c-axis. The so-called multi-layer dislocation multipole configuration was proposed for the dislocation configuration in the crystallites. From the reconstructed strain distribution function of coherent domains, it was concluded that most of them were subject to compressive strains which were probably due to shrinkage phenomena during drying. The intrinsic stresses of crystallites were estimated for uniaxial compressive, hydrostatic-compressive and shear types of deformation. The possibility of dislocation pile-up formation on (00▪1) atomic planes (domain boundaries) was also considered theoretically. It was assumed that the main mechanism which led to failure of the hydroxide was dislocation pile-up. Pile-ups formed against phase inclusions because of the action of external shear stresses. Results were obtained for samples of granite and smoky quartz aggregates.

X-Ray Diffraction Investigations of Deformations and Dislocation Configuration in Calcium Hydroxide Crystallites of Concrete. V.S.Harutyunyan, E.S.Abovyan, P.J.M.Monteiro: Physica Status Solidi A, 2003, 200[2], 307-25