CS - a combined system. It is an expansion glass-fibre reinforced plastic element combined with a reinforcing element. Applied as a flexible connection in sandwich structures with brick lining.
R&D - research and development activities oriented to new knowledge acquisition and their practical application while creating a new item or technology.
Rondel zone - a part of disk-shaped dowel used for pressing the HIM.
BF glass-fibre reinforced plastics - a composite material consisted of a reinforcing glass fibre and a special linking element. A special technology and linking element formulation ensure high product uniformity, high physical-mechanical properties, material temperature stability and durability in corrosive environments.
Composite material (composite, KM) - an artificially created nonhomogeneous solid material consisted of two or more components with a clear interface between them. In most composites (except for layered), components can be separated into the matrix and embedded reinforcing elements. In construction purpose composites, reinforcing elements are usually provide for necessary mechanical properties of the material (strength, stiffness, etc.) and the matrix (or the linking element) ensures a composite action of reinforcing elements and their protection from mechanical damages and aggressive chemical medium. (с) Wikipedia
SPA - an abbreviation from "Glass-fibre reinforced Plastic Rebar". Registered Trade Mark. The trade mark owner is Biysk factory of glass-fibre reinforced plastics, LLC.
Ruspert - a multilayer organozinc anticorrosion coating of self-tapping screws applied in the DK mounting system for roofing materials.
Heat transfer performance nonuniformity factor - a factor indicating to what extent heat-conducting inclusions reduce thermal resistance of the enclosure calculated section
The required thermal resistance - a specified parameter in SNiP determined for different purpose buildings and different regions. It specifies a level of thermal protection from the enclosure. When an enclosure is designed, its thermal resistance should be not lower than this parameter.
Technical certificate - a document confirming suitability for construction purposes for products requirements to which are not duly specified by effective standards (GOST, SNiP).
Tensile modulus Et - a ratio of stress increment to axial rod strain increment as a result of its tensile, compressive or bending loading during control tests.
Creep modulus Ec - maximum ratio of stress increment to rod strain increment as a result of constant tensile, compressive or bending loading leading to rod fracture not earlier than in 96 hours.
Characteristic rod diameter dc - a nominal rod diameter the value of which is included in a product description and it is used at strength calculations of structures during their design.
Characteristic rod resistance [σc] - accessible tensile or compressive strain in the rod as a result of its tensile, compressive or bending loading.
Characteristic tensile modulus [Е] - rod axial tensile modulus used in rod strength calculation with due account for tensile, compressive and bending loads.
Characteristic rod adhesion strength to concrete [τad] - maximum value of shear stress possible to apply to the lateral surface interface between the rod and concrete or cementing mortar.
Characteristic operating temperature [Тo] - a maximum temperature value to which heating of the rod under operational mechanical load is reduced.
Residual strain εs - a maximum residual strain value (nonvanishing after the load removal) in road axial direction developed in it as a result of stress σs in a time not less than in 96 hours from rod tensile, compressive or bending loading.
Ultimate strain εu - a rod axial strain value occurred in it at the moment before fracture as a result of tensile (compressive) or bending loading.
Long-term strength σl - maximum rod axial stress as a result of constant tensile, compressive or bending loading leading to rod fracture not earlier than in 96 hours.
Ultimate strength su - a rod axial strain value occurred in it at the moment before fracture as a result of tensile, compressive or bending loading.
Ultimate adhesion strength τad - a value of shear stress occurred at the interface between the rod and concrete when the rod is broken away from concrete at the moment before fracture.
Perpendicular-to-the-rod-axis shear strength τsh - is perpendicular-to-the-rod-axis shear stress occurred in it at the moment before fracture as a result of shear force oriented perpendicular to the rod axis.
Parallel-to-the-rod-axis shear strength τsh - is parallel-to-the-rod-axis shear stress occurred in it at the moment before fracture as a result of shear force oriented parallel to the rod axis and rod transverse bending.
Rod tear-out from the anchor strength σаt - tensile stress occurred in the rod at the moment of rod-anchor assembly at rod tear-out from an anchor.
Rod pressing-in into the anchor strength σаr - compressive stress occurred in the rod at the moment of rod-anchor assembly at rod pressing-in into the anchor.
Strength at a temperature of 70°С σt(70) - strength determined when testing the rod heated up to 70°С.
Strength at temperature minus 60°С σt(-60) - strength determined when testing the rod cooled down to minus 60°С.
Accelerated aging strength σag - strength occurred while testing rod samples after accelerated aging in a standard aggressive medium under standard conditions.
Specified moist environment - air with moisture from 90% to 100% at temperature (23±5)°С.
Specified acid environment - nitric acid water solution with hydrogen ion concentration С(Н+) = (1.0±0.1) g/litre at temperature (23±5) °С.
Specified alkaline environment - sodium hydrate water solution with С(NaCl) = (58±2) ОН ion concentration С(Н-) = (17±1) g/litre at temperature (23±5)°С.
Specified salt environment - sodium chloride water solution with concentration g/litre at temperature (23±5)°С.
Specified accelerated aging conditions - storage of unloaded samples in a corrosive environment (moist, acid, alkaline and salt) at temperature 50 ºC during 30 days or at temperature 80 ºC during 7 days, or at water or water solution boiling temperature during 24 hours.
Polymer composite rods or composite nonmetal rebar - continuous fibre rods (rovings or glass, basaltic, carbon, aramid, etc. threads) saturated with a polymer linking element with, if necessary, additional surficial layers intended for increasing their adhesion strength with reinforced materials (concrete, cementing mortars and another similar construction materials).
Fusion temperature Tf - temperature when a polymer matrix in the rod composite material transfers from a glass state into the elastic one.
Effective rod diameter de - diameter of such an ideal rod (cylindrical, uniform in material composition and structure) which is equivalent to a cross-sectional area and inertia moment of a real rod and it is used as a model for calculating specific mechanical properties during control, type or certificate tests according to GOST 31938-2012 ("Polymer Composite Rebars for Concrete Structures").