reinforced concrete beams

This article presents the results of an experimental study of damaged reinforced concrete beams. Corrosion of reinforcement in concrete is one of the main problems of durability faced in practice by civil engineers. Particular attention should be paid to the action of an aggressive environment as one of the most common causes of the introduction of elements into an emergency. The aim of the work is to determine the strength and deformability of reinforced concrete structures without damaging the reinforcement and in case of damage. According to the research program 4 beams were tested.

This article presents results of a theoretical study of reinforced concrete beams with damaged reinforcement. The change of micro-hardness of a reinforcing rebar’s with a diameter of 20 mm of A500C steel in the radial direction is investigated and the thickness of the heat-strengthened layer is established. It is established that the thickness of the thermo-strengthened steel layer of the reinforcing bar with a diameter of 20 mm of A500C is approximately 3 mm.

The character of oblique cracking is significantly influenced by the method and reliability of anchoring of the longitudinal tensile reinforcement on the hinge support beams. In many experimental researches the lack of anchoring caused the premature destruction of beams along the sloping cracks. Nevertheless, such destruction of a beam along the sloping crack, at the violation of anchoring on the hinge support, should not be referred to the type of destruction under the influence of internal efforts, caused by the external loading.

The research of reinforced concrete beams, in which there is some damage or defects are scare. This is especially applies to studies in which defects arise under the influence of the load, which is due to the complexity of such studies. This article describes a method for performing damage to stretched rebar in bending reinforced concrete elements under load. There were eight samples tested: four specimens tested as controls and four – with injuries. Control samples with a stretched rebar of 16 and 20 mm in diameter are reinforced. Damaged beams with rebar 20 mm in diameter are reinforced.

This article describes strengthening normal cross-section of reinforced concrete beams with prestressed reinforcement under load. The samples of RC beam with 2100 mm. length, 100 mm width, and 200 mm height was tested. As beam’s tension reinforcement A500C Ø12 mm rebar was chosen. A240C Ø8 mm rebar was chosen as compressed reinforcement. Transverse reinforcement – A240C Ø8 mm rebar located in the supporting area with step 50–100 mm. Class of the concrete was C32/40. The beams were tested for a pure flexure. The load was added using the hydraulic cell in the thirds of the span.

The main results of experimental studies of strength, bearing areas’ are usually uncut, pre-stressed, stretched and eccentrically compressed reinforced concrete beams. Тhe identified of the stated constructions’ bearing areas’ new destruction patterns and the establishment of their dependence on the research factors’ corresponding ratio; the development of new general engineering methods of the studied elements’ bearing areas’ durability calculation based on the choice and the alternating consideration of the most probable destruction schemes.