Flexural Reinforced Concrete Elements Normal Section Bearing Capacity Evaluation in Fracture Stage

Abstract

This article examines flexural reinforced concrete structures condition assessment process in existing buildings on the stage where the reinforcement stress is between the yield and the tensile strength. The research is made on V. Jokūbaitis proposed methodology directly measuring the compression zone height, allowing us to evaluate the behavior of reinforced concrete beam fracture sufficiently precisely. This paper confirms the hypothesis that, when reinforcement reaches yielding stress, elastic strain dominates in concrete‘s compression zone and it is reasonable to use triangular concrete compression zone diagram, without tensile concrete above crack evaluation. The methodology of reinforced concrete structures bearing capacity assessment according to limit normal section crack depth is proposed. There is established connection between bending moments, when reinforcement achieve yielding stress and tensile strength, which allows us to decide about structures bearing capacity reserve. The results are confirmed with experimental studies and calculated values obtained by methodologies based on different reduced stress diagrams of concrete‘s compressive zone.

Crack Width and Load-Carrying Capacity of RC Elements Strengthened with FRP

“…A simplified methodology proposed by Slaitas et al [31] could be used for nonstrengthened RC structures, using a triangular concrete compressive zone stress diagram. 6 International Journal of Polymer Science…”

Load-bearing capacity of flexural reinforced concrete members strengthened with fiber-reinforced polymer in fracture stage

“…The similar results of the flexural strength of RC beams, calculated according to the methods provided by EC2, 52,53 ACI 318, 54 H Rü sch, 55 I Ž idonis, [56][57][58] and V Jok ubaitis and colleagues, 50,51 are obtained. 59 It shows that the distance between the inner resultant forces is very similar when assuming triangular, curved, or equivalent rectangular diagrams of concrete stress distribution in compressive zone (see Figure 1). When assuming triangular distribution of concrete stresses within the compressive zone, the internal forces shown in Figure 1(a) and (b) could be calculated using the equilibrium conditions…”

“…59 It shows that the distance between the inner resultant forces is very similar when assuming triangular, curved, or equivalent rectangular diagrams of concrete stress distribution in compressive zone (see Figure 1). When assuming triangular distribution of concrete stresses within the compressive zone, the internal forces shown in Figure 1(a) and (b) could be calculated using the equilibrium conditions…”

“…Figure 1. State of stress when using: (a) triangular concrete compressive zone diagram and (b) curved concrete compressive zone diagram 59. …”

Flexural Reinforced Concrete Elements, Strengthened with Fibre Reinforced Polymer, Bearing Capacity Evaluation According to Limit Crack Depth

“…Tai reiškia, kad vidinių jėgų peties ir gniuždomojo betono atstojamųjų sandaugos, naudojant trikampę ir kreivinę betono gniuždomosios zonos diagramas, yra panašios (2 pav.) (plačiau Slaitas et al 2017).…”