Analysis of durability of steel-fiber concrete structures under conditions of sign-variable temperatures

The introduction of technologies for the production of building structures using modern building composite materials with indicators of high reliability and durability is an urgent task for the construction industry. The increasing use of fiber-reinforced concrete is facilitated by the construction of unique buildings and structures, which are subject to requirements for a guaranteed level of safety and durability. The article analyzes domestic and foreign developments on the study of the durability of steel-fiber-concrete structures, analyzes the strength of steel-fiber-concrete structures during testing in real construction conditions. The authors carried out experimental tests for the separation of steel-fiber-reinforced concrete structures under conditions of sign-variable temperatures. Tests showed an increase in compressive strength by 1.4 times, tensile strength in shearing - up to 2 times, tensile strength in bending - by 15 ... 20%. In the following months (20….40 months) the strength characteristics remained stable. It is concluded that strength tests of steel-fiber-reinforced concrete structures, especially under conditions of sign-changing temperatures, are long-term, time-consuming and costly.