Plastic hinge properties play a crucial role in predicting the nonlinear response of structural elements. The plastic hinge region of Reinforced concrete normal beams has been previously studied experimentally and analytically. The main objective of this research is to evaluate the behavior of the plastic hinge region of Reinforced concrete deep beams and its comparison with normal beams through finite element simulation. To do so, ten beams contain six deep beams, and four normal beams, under concentrated and uniformly distributed loading, are investigated. Lengths in the plastic hinge region involving curvature localization, rebar yielding, and concrete crushing zones are studied. The results indicate that the curvature localization zone is not suitable for the prediction of plastic hinge length in Reinforced concrete deep beams. Based on the results it can be stated that in simply supported normal beams the concrete crushing zone is focused on the middle span, but in simply supported deep beams by creating a compression strut between loading place and support, the concrete crushing zone spreads along the compression trajectory. The rebar yielding zone of simply supported beams increases as the loading type is changed from the concentrated load at the middle to the uniformly distributed load.

This paper presents improved analytical method for predicting deflection of Reinforced concrete beams. This approach considers stiffness of steel and concrete separately. A number of diverse analytical models have been proposed by various researchers aimed at accurately predicting deflection of Reinforced concrete bent elements. In this paper energy model is formed and varied. Deflection is determined from the potential energy model. To establish the validity of the proposed model correlation of analytical solution of existing models are conducted. Variation model solutions generally show very good agreement with results obtained other analytical methods.

Self-consolidating concrete (SCC) is a relatively new approach to making concrete, and it is characterized by its high flowability and resistance to aggregate segregation in the plastic state. A total of 3 beams were tested in this experimental investigation on the flexural ductility of Reinforced concrete beams made with self-consolidating concrete. The beams were made from concrete having average compressive strength of 30 MPa and reinforcement ratio in the range of 0.15-1.38. Three self-consolidating Reinforced concrete beams with different percentage of and constant amount of were cast and incrementally loaded under bending. During the test, the strains on the concrete middle face and on the tension and compression bars as well as the deflection at different points of the span length were measured up to failure. This paper compares the ductility of Reinforced beams cast with SCC concrete to the theoretical calculations based on two codes (ACI, CSA) recommended for the Reinforced concrete members that vibrated into place to ensure proper filling and consolidation. Based on the results obtained, effect of increasing tension reinforcement on the curvature and displacement ductility of the self-consolidating concrete Reinforced members is more deeply reviewed. Comparisons between theoretical and experimental results are also reported here. Generally, it was concluded that, self-consolidating Reinforced concrete beams yielded greater ductility as opposed to the theoretical calculations based on two codes (ACI, CSA) recommended on conventional Reinforced concrete beams.

Deep beams are type of beams which their behavior is different from conventional beams because of their particular type of geometry. In this paper, the retrofitting of these beams is considered and 10 deep beams are tested experimentally and discussed about retrofitting methods. Experimental studies indicate that the use of CFRP bands in the direction perpendicular to diagonal cracks in comparison with the use of CFRP in vertical direction are appropriate in condition that many CFRP with less width be used instead of using wide CFRP with lower number. The comparison of the experimental results is conducted with the results of existing relations in literature. The comparison shows that the existing relations cannot correctly predict the behavior and ultimate load of deep beams retrofitted by FRP tested in this paper.

In the present study, a new method for retrofitting Reinforced concrete beam is introduced in which steel-concrete composite jackets containing steel fiber is used. For this purpose, 75% of the peripheral surface of Reinforced concrete beams was initially Reinforced using steel plates and bolts, and steel fiber Reinforced concrete was used between the steel plates and the peripheral surfaces of the beam. Thus, due to the relatively high tensile strength of concrete Reinforced with steel fibers, not only the cross-section and moment of inertia of the beam will increase, but the tensile strength of the beam will also increase. The variables studied were steel fiber value (0, 1 and 2% by volume of concrete) and type of retrofitting (concrete jacket, steel-concrete composite jacket, and carbon fiber Reinforced polymer (CFRP) sheet). Thus, 8 Reinforced concrete beams were constructed and their response to four-point loading was compared by examining the parameters such as crack load, yield load, ultimate load, ductility, stiffness, and energy absorption capacity. The results showed that steel fiber-Reinforced composite jackets delay the formation of the first crack in concrete and the yield of steel rebars with confinement and they result in an increase in energy absorption capacity of the beams by 89 to 129% depending on the amount of steel fiber. On the other hand, the use of steel-concrete composite jackets, due to their higher flexural stiffness, exhibits higher flexural capacity compared to steel-Reinforced concrete jackets and CFRP sheets. They have a much better performance in terms of ductility.