Few relations were presented in the literature for computing the shear strength of prestressed concrete deep beams. However, these relations have shortcomings to predict the ultimate load of such members. In this study, a new simple model based on Strut-and-Tie Model (STM) was put forwarded to obtain the ultimate load of prestressed reinforced concrete deep beams and seven specimens were tested experimentally. The effects of prestressing were considered by using an equivalent load and added members of the truss in the proposed model. This model can control the flexural, bearing and shear modes of failure. In order to verify the suggested model, the results were compared with experimental data. The accuracy of the proposed model was shown by

Reinforced Concrete (RC) deep beams are commonly used in structural design to transfer vertical loads when, there is a vertical discontinuity in the load path. Due to their deep geometry, force distribution within the RC deep beams is very different from RC shallow beams. There are some Strut- and- Tie Models (STM) developed for RC deep beams. However, most of these models are developed for RC deep beams with simply supported boundary condition, not applying for RC deep beams with fixed-ended condition. In this paper, a novel curved STM was developed to simulate load capacity and failure mode of fixed-ended RC deep beams subjected to monotonic and cyclic point loads. Curved STM has double main struts and fan-shaped sub struts to simulate fo

The end support of deep beams could have different effects on behavior of the beams. In this paper, experimental results of 43 deep beams with span -to -depth ratio of less than 3, different reinforcement arrangements and boundary conditions were investigated and discussed. Results indicated that, boundary conditions have important effects on ultimate loads, modes of failure and deflections; but crack formation and their patterns are almost the same irrespective of applied boundary conditions. Furthermore, the ultimate loads of the beams with fixed ends are 1.2–6 times of simply supported and continuous deep beams, depending on amount of main bottom and top reinforcements. Furthermore, in fixed -end deep beams, modes of failure and ultima

The high depth created favorable space for placing the openings which are to provide some capabilities such as mechanical and electrical installations, but these openings reduced load bearing capacity of the beams. One solution to the mentioned shortcoming is to use FRP-Composite sheets; the effect of FRP-Composites in improving load bearing and ductility of concrete members such as columns and beams is approved in previous investigations. This study utilizes the CFRP sheets to compensate for weakness arisen from the created openings. To this end, 5 deep beams with 10x50x120 cm dimensions, each having two circular openings with 20 cm diameter placed in symmetrical order, are constructed and undergone a three-point monotonic bending. The Ext

Deep concrete beams are the structural members that have different behaviors compared with normal beams. The high depth of these beams has made them favorable for placing the openings, which results in decreased load bearing capacity. This study utilizes the CFRP sheets to compensate the weakness arisen from the created openings. To this end, 10 deep beams with 10 ? 50 ? 120 cm dimensions, each having one or two circular openings with 20 cm diameter placed in both symmetrical and asymmetrical order, are constructed and undergone a three-point monotonic bending. The Externally Bounded Reinforcement (EBR) and Externally Bounded Reinforcement On Grooves (EBROG) methods have been utilized to install the FRP sheets in three configura

A new simple strut-and-tie model was presented in this paper to study the behaviour of reinforced concrete deep beams. This model was obtained based on bottle-shaped struts that can predict flexural, bearing and shear modes of the failure. Also, the effect of web reinforcements was considered. The proposed model was verified by laboratory test results that obtained from five deep beams with a shear span-to-depth ratio of two and some other experimental results existing in the literature. Comparison of the results of the proposed model with relations from ACI 318 and AASHTO-LRFD codes and some other relations showed that the proposed model is efficiently capable of accurately predicting the ultimate load of simply supported deep beams. Also,

Reinforced Concrete (RC) deep beams are commonly used in structural design to transfer vertical loads when there is a vertical discontinuity in the load path. Due to their deep geometry, the force distribution within the RC deep beams is very different than the RC shallow beams. There are some strut and tie model (STM) already been developed for RC deep beams. However, most of these models are developed for RC deep beams with the simply supported boundary condition, which do not apply for RC deep beams with the fix-ended condition. In this paper, five fixed-end RC deep beams have been tested experimentally which were subjected to monotonic and cyclic loads. Also, a simple STM was proposed to simulate the load capacity and failure mode of fi

Shear walls are used in towers as lateral loading resistance. Composite steel shear wall (CSSW) because of high stiffness and deformability are widely used. This wall made of a thin steel plate with reinforced a concrete layer, which is attached to one or both sides of the steel plate. This system is similar to stiffened steel plate shear wall. The present experimental and numerical studies were focused on the effects of opening used as windows or doors in buildings on the CSSW behavior. Experimental studies results of one and three-story CSSWs with the scale of 1:3 are reported. In addition, the effects of opening size and location are insignificant on the composite steel shear walls behavior. Results showed that opening dec

4-ConclusionsThe experimental program indicates that in order to increase the ultimate load of deep beam it is better to use more FRP bands with smaller width instead of using fewer CFRP bands with larger width.Also, a comparison implemented between the experimental results with the obtained results from the existing relations in the literature shows that there are no appropriate code recommendations specifically for deep beams strengthened with FRP. The only existing relations are the ones obtained by Zhang et al., in 2004 whose results are very conservative. Thus, none of the existing relations in the investigated references can predict the behavior of deep beams strengthened with FRP tested in this paper properly.

In many cases concrete shear walls have openings for architectural reasons.opning cause? some changes in shear capacity,stiffness and behavior of reinforced cocncrete walls.In this study,finite element models are developed by Abaqus software to compare the effect of area and position of opening on shear capacity of concerete shear wall with regular openings. the experimental results on? cocncrete shear walls with two bands of openings by Aguda are used to verify the the analytical models.after verification; Some specimens with one and two bands of opening are designd similiar to qulification of Agudas experiments.Nonlinear finite element? analysis of? reinforced cocncrete walls is performed using damage plasticity model. Results further con

Deep beams are the members that their behavior is different from conventional beams due to their special geometry and loading condition. Due to the low thickness compared with the height of the beams, the flexural reinforcement’s ratio is usually high and need to be placed in several layers. One of the most effective ways to reduce the ratio of the flexural reinforcement is to use of the prestressed reinforcement instead of conventional reinforcement which more conventional reinforcement can be replaced by a prestressed reinforcement. If that happens, there will be discussion of prestressed deep beams. In recent decades, along with the serious discussion of prestressed deep beams, reinforced concrete members retrofitted with FRP are also