EXPERIMENTAL STUDIES OF THE STRESSED AND DEFORMED STATE OF REINFORCED CONCRETE ARCHES OF HIGH STRENGTH CONCRETE

Abstract

Currently, the use of reinforced concrete arches is expanding during the construction of buildings and structures, in particular for fortifications and for civil defense buildings. Particularly noteworthy are the arches, which are made of high-strength concrete, which helps to reduce the weight of structures and loads on other structural elements of buildings and foundations. But studies of the peculiarities of the work of such arches under load today are virtually absent.

The article presents the results of experimental studies of the stress-strain state of models of arches made of high-strength concrete, the cup strength of which exceeded 60 MPa. The construction of arches with a design span of 2 m and a lifting boom of 0.4 m is described. The cross section of the arches was 0.14 × 0.10 m. The arches were reinforced with a flat frame with longitudinal reinforcement from 2Ø10 A500C rods.

Two arches were tested by applying a load of two concentrated forces according to the scheme of pure bending of the beam. The supports of the arches were hinged. The load in a special installation was applied in stages. The magnitude of the concentrated forces and the gap was measured using rammed jacks. Load processes measured deformations of concrete, reinforcement and deflections in the middle of the arch. Tens meters, indicators and prognometers were used for this purpose.

Cubes and prisms were made to establish the mechanical characteristics of concrete and tested according to standard methods. Chemical additives were introduced into the concrete. According to the results of testing concrete and reinforcing samples, their mechanical characteristics were established, which were used in the theoretical determination of the bearing capacity of arches.

Experimental studies of high-strength concrete arches allowed the length of the arches and establish the nature of the destruction of the arches. The theoretically determined values ​​of the destructive forces according to the deformation technique using a two-line diagram of concrete deformation satisfactorily coincide with the experimental data.