About the authors
First name, Middle name, Last name, Scientific degree, Scientific rank, Current position. Full and brief name of the organization, The organization address. | Akhmetzianov F.Kh. – candidate of technical sciences, associate professor E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it Kazan State University of Architecture and Engineering The organization address: 420043, Russia, Kazan, Zelenaya st., 1 |
Title of the article | The reasons of occurrence of microdamageability cement stone and concrete in the course of hardening |
Abstract. | Twenty kinds of defects and damages (D&D) of the cement stone (concrete), arising during the hardening period of material of building elements, are placed in article. In the conditions of influence the D&D can become damages of material structure. The list of D&D collected under references, is established on the basis of researches of many authors with the use of various methods and approaches of physics, physical chemistry, mechanics of deformation of a firm body. Mechanisms of reorganization of structure of crystalline particles and polycrystals of a cement stone are described at occurrence of defects and the damages, leading to change of local mechanical properties. The reasons of splitting in cement stone are found out at mechanical influences. Conclusions: - In the cement stone (concrete) the mechanical properties of crystals and polycrystals depend on the ratio of low-angle (? ? 10 ... 150), and large-angle borders. Due to the relatively small number large-angle borders intergranular and plastic deformation are suppressed, which leads to spalling of the areas having stress concentrators (long capillaries submicrocracks etc.). - In the cement stone number of dislocations is reached up to 1011 ... 1012, that is enough to start the slides and the emergence of embryonic microcracks up to 36...480 ?. - At angles ? ? 30 border deformation origin have a strong structure. Many border broken off inside the crystal, causing a break along the line sources of elastic stresses of dislocation type. |
Keywords. | A cement stone (concrete), crystals and polycrystals, defects and damages, small and big angular borders of crystals and polycrystals. |
For citations: | Akhmetzianov F.Kh. The reasons of occurrence of microdamageability cement stone and concrete in the course of hardening // Izvestiya KGASU. 2013. №4(26) P.92-100. |