reinforced concrete beam

In accordance with current conditions, it is necessary to change the aim of buildings and structures in which a large number of reinforced concrete elements that undergo complex stress-deformed states are used. The task for researchers is to determine the residual bearing capacity of the element with uneven damage, making it possible to choose the most optimal calculation option and select materials for optimization, preservation of strength, and durability.

Due to economic trends in the building industry, the investigation of the residual bearing capacity of reinforced concrete elements has been receiving more and more attention in recent years. Studying the effect of damage on the bearing capacity of reinforced concrete elements is one of the main themes of investigation in this field. Results of 4 reinforced concrete beams’ testing are proposed, one of which was the control one (tested without damages) and three- typically damaged in the compressed zone at different load levels.

Traditional building materials are regularly improved, finding new operational characteristics and complementing the quality of technical parameters. For a long time and now as reinforcement of reinforced concrete elements is steel. Corrosion of steel and conductiveness, prompted researchers to improve the quality of reinforcement, as a result of which non-metallic composite reinforcement was created. Composite materials are a group of reinforcing bars that differ in the type of feedstock, consisting of two or more components.

In nowadays economic trends, there is a need in changes in the usage of buildings and structures. This usually leads to the changes loading and character of the loadings type on the building structures, with the subsequent need to assess the technical condition and the replacement or enhancement of certain elements. Also, objects, which need the reconstruction in order to be reequipped or changed it functionality, that have designs which were used under the influence of an aggressive environment or other factors which were not taken into account.

Every construction is influenced by different factors during operation. As a result, there are various defects and damage of these elements, which affects their operating condition. One of such defects is the corrosion of the working rebar. Investigation of samples with corrosion is a complicated and labor-intensive process. Instead of corrosive effects, we perform controlled valves of damaged. In this way, we obtained experimental samples with a fixed value of reducing the diameter of the valve.

Today there are many scientific and technical knowledge that make construction a reliable, fast and economical. To provides a safe and durable (the fundamental components of reliability) of builnings and structures are developed the methods of reliability theory. Improving the methods of calculation is enables researchers and designers to create effective structures with a preset (expedient) level of reliability, which directly affects to an amount of required materials and, appropriately, a cost of future building objects in general.

In the article the calculation of the bearing capacity of the inclined cross-sections of the reinforced concrete elements using an external composite reinforcement designing by deformation model DBN V.2.6.-98: 2009 and engineering methodology presented in SNIP 2.03.01-84 are described.

Development and improving for the research methods of reinforced concrete beams are actually one for more researchers. Considering the test of reinforced concrete beams on the shear should be noted that one test is carried out to study the two inclined cross sections of the beam.Usually there destruction of both cross section of the beam appears not simultaneously. We get shear strength only by strength of one inclined cross section. This approach to the researching is economically unreasonable. It is proposed to conduct research inclined cross sections individually.

The paper discusses experimental study of oblique planes of reinforced concrete solid beams at simultaneous exertion of constant transverse force and positive and negative bending moments. The tested beams had similar characteristics and differed only in types of reinforcement of oblique planes. Analysis of experimental results revealed the specifics of development and width of oblique cracks in the zone of effect of constant transverse force and positive and negative bending moments. The dynamics of development and width of oblique cracks depending on the load was recorded.

The priority task for researchers of building structures is developing methods of calculation, which would allow performing constructions calculations with higher accuracy, preserving the reliability of the design. This especially concerns of calculation inclined cross sections of reinforced concrete beams given their sharp, sudden and brittle fracture and difficult stress strain state. Improving methods for calculating will provide the lower expense of materials when designing reinforced concrete structures and allow more efficient using all elements that make the construction.