Hydration hardening bridging crystals

In agreement with the concepts developed by Polak [10], the appearance of a contact nucleus may take place when the new crystalline phase forms in the contact zone between the newly formed crystals in the course of crystallization from metastable solutions. The bridging of crystals results in the formation of fine disperse polycrystalline products, such as those formed during hydration hardening of mineral binders and cements. 

In order to cause bridging between crystals and particles, one needs to apply external compressive forces. In the laboratory studies, these forces were introduced by applying suitable compression. However, in the course of hydration hardening, such forces are originated in the system internally. One is thus faced with the need to answer a number of questions. Specifically, what is the origin of those forces in the process of structure formation What are the nature, magnitude, and... 

In summary, one can say that x-ray diffraction stndies have proven the presence of residual stresses in the strnctnres formed in the conrse of hydration hardening and have made it possible to quantitatively estimate their magnitude under varions physical-chemical conditions. The stresses that originate in the conrse of crystal bridging can reach hundreds of kg/cm and manifest themselves in many different ways depending on the hydration hardening conditions. In particular, the stresses can nndergo partial or complete relaxation in the course of the plastic deformation of the... 

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