Euro Code Research Articles

Reconciling Eurocode 8 Part 1 and Part 2 Two-component Record Selection

ABSTRACT Eurocode 8 (EC8) allows the use of dynamic analysis for the design and assessment of structures and provides some constraints for the selection of acceleration time-histories as seismic input. However, when it comes to the selection of two-horizontal-component natural ground motion records, parts 1 and 2 of EC8, stipulate apparently different criteria. The first aim of this paper is to build up on previous studies and investigate whether this difference in provisions translates into the selection of systematically different sets of records. A series of record selection case-studies presented in this study, corroborate the preliminary findings of previous work, and show that this is not the case, that is, record sets chosen according to one group of criteria tend to satisfy the other by default. A second aim is to investigate the different options for selecting multi-component ground motion records in part 1, which turn out to be equivalent. Finally, a third issue tackled is the effect that different definitions of spectral acceleration, that the design spectrum refers to, can have on spectrum-compatible record selection, when two horizontal components are involved. The results indicate that, for some of these alternative definitions, such as maximum or random component spectral acceleration, sets obtained via direct spectrum compatibility may not always agree with a simple application of Eurocode 8 provisions. On the other hand, when spectral acceleration is defined as the geometric mean of the two components, consolidated record selection algorithms appear to guarantee spectrum compatibility.

Post-fire behaviour of cold-formed high strength steel tubular T- and X-joints

An experimental programme to investigate the post-fire residual strengths of cold-formed high strength steel (CFHSS) tubular T- and X-joints subjected to ISO-834 standard fire [1] exposure has been presented in this study. A total of 32 joints, including 16 T-joints and 16 X-joints, was tested. The tubular members of T- and X-joints were made of S900 and S960 steel grades. The test specimens were divided into 3 sets, and subsequently, these sets were then heated up to 300 °C, 550 °C and 750 °C by generally following the ISO-834 standard fire [1] curve, respectively. Once the fire exposed tubular T- and X-joints cool down to ambient temperature, tests were then conducted. The brace members of tubular T- and X-joints were made of square, rectangular and circular hollow sections (SHS, RHS and CHS), while SHS and RHS were used as the chord members. In this study, two configurations of tubular T- and X-joints were tested, first, where SHS and RHS were used as the brace and chord members (i.e. RHS-RHS), and second, where braces were made of CHS and chords were made of SHS and RHS (i.e. CHS-RHS). The T-joints were tested by applying axial compression load through the brace members and the chord ends were supported on rollers. The X-joints were tested by applying axial compression load through the brace members without chord preload. The welding was performed using automatic gas metal arc welding process. For T- and X-joints, the nominal values of brace-to-chord width ratio (β) ranged from 0.42 to 1, brace-to-chord thickness ratio (τ) ranged from 0.75 to 1, chord width-to-thickness ratio (2γ) ranged from 25 to 35 and chord side wall slenderness ratio (h0/t0) ranged from 15 to 35. Currently, there are no specific design rules to predict the post-fire residual strengths of tubular joints. Thus, the post-fire residual joint strengths obtained in this investigation were compared with the nominal strengths calculated from the CIDECT [2] and Eurocode 3 (EC3) [3] using the measured post-fire residual mechanical properties. It is shown that the current design rules of T- and X-joints given in the CIDECT [2] and EC3 [3] could not accurately predict the post-fire residual strengths of cold-formed S900 and S960 steel grades tubular T- and X-joints.

Optimized Design of Cold‐Formed Steel Elements for Serviceability and Ultimate Limit States

AbstractCold‐formed steel (CFS) sections are gaining ever increasing popularity in modern construction practice due to their advantages, such as efficient material use and sustainability. While the manufacturing flexibility of CFS cross‐sectional shapes brings innovative and complex shapes within practical reach, obtaining optimum design solutions can be a challenging task due to the complex mechanical behaviour of CFS elements, which is controlled by local, distortional and global buckling modes, as well as the need to account for manufacturing and end‐use constraints. This study presents a practical framework for the development of optimised CFS beam sections with maximum flexural strength and minimum deflections in ultimate and serviceability limit state conditions, respectively, in accordance with Eurocode 3 (EC3). A population‐based Genetic Algorithm optimisation method is employed to obtain optimum solutions for ten different CFS cross‐section prototypes, while the EC3 geometric restrictions and a number of manufacturing and end‐use constrains are also considered. It is shown that sections optimised based on serviceability limit state (SLS) and ultimate limit state (ULS) requirements can provide up to 44% higher effective stiffness and 55% higher bending moment capacity, respectively, compared to standard commercial lipped channel sections with the same amount of material. The results also indicate that using optimised plain channels and folded‐flange sections generally leads to the best design solution in SLS and ULS optimization, respectively.

Performance of steel moment-resisting frames in post-earthquake horizontally traveling fire

PurposeThe study investigates the performance of a three-story unprotected steel moment-resisting frame (SMRF) designed for high seismic demand in the fire-only (FO) and post-earthquake uniform and traveling fires (PEF). The primary objective is to investigate the effects of seismic residual deformation on the structure's performance in horizontally traveling fires. The traveling fire methodology, unlike conventional fire models, considers a spatially varying temperature environment.Design/methodology/approachMulti-step finite element simulations were carried out on undamaged and damaged frames to provide insight into the effects of the earthquake-initiated fires on the local and global behavior of SMRF. The earthquake simulations were conducted using nonlinear time history analysis, whereas the structure in the fire was investigated by sequential thermal-structural analysis procedure in ABAQUS. The frame was subjected to a suite of seven ground motions. In total, four horizontal traveling fire sizes were considered along with the Eurocode (EC) parametric fire for a comparison. The deformation history, axial force and moment variation in the critical beams and columns of affected compartments in the fire heating and cooling regimes were examined. The global structural performance in terms of inter-story drifts in FO and PEF scenarios was investigated.FindingsIt was observed that the larger traveling fires (25 and 48%) are more detrimental to the case study frame than the uniform EC parametric fire. Besides, no appreciable difference was observed in time and modes of failure of the structure in FO and PEF scenarios within the study's parameters.Originality/valueThe present study considers improved traveling fire methodology as an alternate design fire for the first time for the PEF performance of SMRF. The analysis results add to the much needed database on structures' performance in a wide range of fire scenarios.

Experiments on stainless steel hybrid K-joints with square braces and circular chord

This paper presents an experimental investigation on the load-bearing capacities of stainless steel hybrid tubular K-joints with square braces and circular chord. All test specimens were made from austenitic stainless steel of grade AISI 304. For gapped K-joints, as the gap (g) increased, initial stiffness and load-bearing capacities of joints decreased continuously. For overlapped K-joints, the overlap ratio (Ov) did not have a significant effect on the initial stiffness and load-bearing capacities of joints. For the same series of joints with the identical cross-sectional dimensions, the load-bearing capacities of overlapped K-joints were higher than those of gapped K-joints. Test results were also compared against the design predictions in accordance with the current design guidelines of CIDECT (2008), Eurocode 3 (EC3) (2005), Australian/New Zealand Standard (AS/NZS) (2001) and Chinese Code (GB 50017) (2017). Upon comparison, it was found that the GB 50017 (2017) can predict the load-bearing capacities of stainless steel hybrid tubular gapped K-joints accurately, being around 5% conservative to the test results. However, CIDECT (2008) predictions were found to be conservative by 23% on average. In comparison, the nominal strengths calculated from the EC3 (2005) and AS/NZS (2001) are conservative by 28% and 15%, respectively, when compared to the test results for stainless steel hybrid tubular overlapped K-joints.

Seismic Performance of RC Beam–Column Joints Designed According to Older and Modern Codes: An Attempt to Reduce Conventional Reinforcement Using Steel Fiber Reinforced Concrete

An analytical and experimental investigation was conducted herein to examine the cyclic load behavior of beam–column joint subassemblages, typical of both the modern reinforced concrete (RC) structures and of the pre-1960s–1970s existing ones. Seven exterior RC beam–column joint subassemblages were constructed and subjected to earthquake-type loading. Three specimens were designed according to the requirements of the Eurocode (EC) for ductility class medium (DCM), while the other three specimens possessed poor seismic details, conforming to past building codes. The hysteresis behavior of the subassemblages was evaluated. An analytical model was used to calculate the ultimate shear capacity of the beam–column joint area, while also predicting accurately the failure mode of the specimens. It was clearly demonstrated experimentally and analytically that it is possible for excessive seismic damage of the beam–column joint region to occur when designing according to the current European building codes. In addition, the proposed analytical model was found to be very satisfactory in accurately predicting seismic behavior and in preventing the premature brittle shear failure of the joints. The seventh subassemblage, constructed with steel fiber RC and significantly less transverse reinforcement than that required according to the EC, exhibited satisfactory ductile seismic performance, demonstrating the effectiveness of the proposed design solution.

Optimal ductility enhancement of RC framed buildings considering different non-invasive retrofitting techniques

Existing RC framed buildings lack significant ductility, especially when they have been built with pre-code criteria. Improving their ductile capacity can help to prevent them from the brittle collapse mechanism and to reduce the seismic damage expected. This paper aims to investigate the enhancement of the ductile response behaviour of RC framed buildings considering different non-invasive retrofitting techniques. To do so, a pre-code RC framed school located in the Spanish province of Huelva has been selected as a case study. Five non-invasive retrofitting techniques have been tested: FRP wraps and steel jackets in columns, steel beams and plates under RC beams and single steel braces. They have been selected so that they can be easily implemented in the building. Some of them have been studied in detail in previous works and others have been included for further research in this paper. In order to compare the results obtained, the most typical technique in the seismic retrofitting of RC framed buildings, the addition of X-bracings in bays, has also been tested. Most previous studies on the seismic retrofitting of RC buildings are focused on validating a method based on artificial models. This paper compares the different techniques in terms of the capacity improvement and the damage reduction, performing analyses in detail and adding them in an existing RC building. A sensitivity analysis has been carried out to determine the influence of each technique in the building’s ductile capacity considering the finite element method. Nonlinear static analyses have been performed to obtain the capacity, the displacement ductility factor (μ) and the behaviour factor (q) of each model defined. The damage expected has been determined considering the ductile and fragile failure of the elements according to the Eurocode-8 (EC8) requirements. To analyse the suitability and the efficiency of each solution, a benefit/cost ratio has been obtained taking into account the ductility improvement and the damage reduction with regards to the retrofitting costs. The results have shown that the best benefit has been obtained with the addition of steel braces. However, the optimal solutions have been single braces and steel jackets due to their combination between benefit and cost. It has been observed that the solutions that increase the stiffness of the joints have had a higher improvement due to the key role that joints have in the resistant capacity of RC structurers. Also, it has been obtained that the values of the fundamental periods have been reduced, when adding the retrofitting elements and materials, up to 30% owing to the increase of the stiffness of the system. Finally, it must be highlighted that a detailed analysis of the behaviour of the whole building must be conducted in order to avoid additional rotation effects and shear forces that could worsen the building’s seismic behaviour.

The Proposition of an EI Equation of Square and L–Shaped Slender Reinforced Concrete Columns under Combined Loading

The stability and strength of slender Reinforced Concrete (RC) columns depend directly on the flexural stiffness EI, which is a major parameter in strain calculations including those with bending and axial load. Due to the non-linearity of the stress-strain curve of concrete, the effective bending stiffness EI always remains variable. Numerical simulations were performed for square and L-shaped reinforced concrete sections of slender columns subjected to an eccentric axial force to estimate the variation of El resulting from the actual behavior of the column, based on the moment-curvature relationship. Seventy thousand (70000) hypothetical slender columns, each with a different combination of variables, were used to investigate the main variables that affect the EI of RC slender columns. Using linear regression analysis, a new simple and linear expression of EI was developed. Slenderness, axial load level, and concrete strength have been identified as the most important factors affecting effective stiffness. Finally, the comparison between the results of the new equation and the methods proposed by ACI-318 and Euro Code-2 was carried out in connection with the experimental results of the literature. A good agreement of the results was found.

Initial rotational stiffness of end-plate connections based on the theory of plates and shells

With current developments in the optimization design of the building structure, and due to the need for the optimization design to carry out multiple iterative calculations, the accuracy and efficiency of these structural calculations are increasingly required. However, the traditional calculation method of the initial rotational stiffness (Rini) of the beam-to-column connection has certain limitations, and the efficiency of the finite element calculation method is poor. To establish an accurate method for predicting the initial rotational stiffness of major- and minor-axis end-plate connections, the theory of plates and shells and the finite difference method (FDM) are used to analyze the connection following the base on component method. In this study, boundary condition equations were established first based on the theory of plates and shells, for components that undergo significant lateral deformation, namely, the end-plate, column flanges, and column web. Then, the FDM was employed to solve these equations to determine the deformation of these components. Considering the deformation compatibility conditions as well as the force equilibrium conditions, the bolt load at the unit moment was calculated. Finally, based on the stiffness of each of connection components and the bolt load, the Rini of an end-plate connection was calculated. A comparison of the Rini values calculated by the proposed method and those obtained from the experiment (EX), finite element analysis (FEA), and Eurocode 3 (EC3) indicated that the proposed method is more accurate.

Collapse performance assessment of steel moment frames designed to Eurocode 8

This paper reports on a study performed on steel moment-resisting frame buildings with the aim of evaluating the safety margins against collapse of buildings designed according to Eurocode 8 (EC8) when subjected to maximum considered earthquake ground motions. To this end, the methodology proposed in FEMA P695 is employed. A set of 360 archetype buildings are designed according to EC8 using code-prescribed behaviour factors for medium and high ductility class structures. Additionally, behaviour factors determined according to an Improved Force-Based Design (IFBD) methodology are also adopted. IFBD allows for a more rational selection of the behaviour factor and is fully compliant with the EC8 prescriptions. The results from the seismic performance assessment of the structures allow for an improved understanding of the seismic behaviour of steel MRFs designed according to EC8 and highlight the efficiency that is achieved with the adoption of the IFBD methodology, both in terms of reductions of steel weight as well as in terms of the consistency between the design assumptions and the ductility demand that is explored from the buildings. Moreover, the results also indicate that moment-resisting frame buildings designed according to EC8 are characterized by acceptable safety margins against collapse.

Experimental study on local buckling of high-strength Q960 steel columns at elevated temperatures

High-strength steel has been widely used in many engineering structures owing to its enormous economic benefits. A considerable amount of theoretical and experimental research on the fire resistance of high-strength steel structures has been reported. Most of the research has focused on the mechanical properties of steel and the overall buckling behavior of members, but less work has been done on the local buckling behavior, which is often observed in steel structures subjected to actual fires. Moreover, very few design provisions in codes and standards are available for calculating the local buckling capacity of steel columns under high temperatures. In this study, eight welded H-section columns (groups A and B) made of high-strength Q960 steel were tested under axial compression at ambient and elevated temperatures to investigate their local buckling behaviors. By considering different buckling zones, heating temperatures, and heating methods, the load–axial displacement, load–lateral deflection, and local buckling zone of steel columns were recorded. Compared with the ambient temperature test results, the ultimate load of group A specimens at 480 and 632 °C decreased by 26.1% and 57.2%, respectively, and the ultimate load of group B specimens at 472 and 683 °C decreased by 28.5% and 74.2%, respectively. The critical buckling temperature of the columns in transient-state testing was higher than that in steady-state testing under the same load conditions. A finite element model was established using the ABAQUS finite element software and was validated by the test results. The experimental values were compared with the design methods proposed in Eurocode 3 (EC3). The results reveal that EC3 is unsuitable for calculating the local buckling capacity of H-section Q960 steel columns at elevated temperatures.

Effects of ground motion spectral shapes on the design of seismic base isolation for multi-story building according to Eurocode 8

Seismic isolation bearing has been considered an effective solution for constructions in earthquake areas. However, the isolator design criteria are strongly depended on the earthquake properties, especially the spectral shapes of ground motions. This paper presents the seismic responses of isolated building structures affected by earthquakes with different spectral shapes as per the specification of Eurocode 8 (EC8). The equivalent bilinear model is used for addressing the seismic behaviour of isolators. A parametric study presents a simplified estimation procedure for seismic responses of isolated structures and isolator’s properties by using the single-mode spectral analysis approach performed on an equivalent simplified model of isolated buildings. Numerical analyses are conducted on three-dimensional models of a typical multi-story building to study the impact of spectral shapes on the seismic responses and the design requirements of isolated structures. Nonlinear time-history analyses are carried out using Etabs software, where the historical seismic records used for modelling have been scaled to match the target spectrum according to EC8. The results show that the seismic spectral shapes have significant effects on the seismic demands of isolated structures and the isolator’s properties, especially the initial characteristic strength Q. The seismic performance requirements of isolators, particularly the energy dissipation capacity, for type I spectra are significantly higher than for type II spectra. Furthermore, isolators designed for type I spectra provide an over-efficient and are considered to be inappropriate for the structures located in earthquake regions with type II spectra.

Local and distortional buckling behaviour of back-to-back built-up aluminium alloy channel section columns

The use of aluminium alloy channel sections is becoming popular in lightweight structures, especially for pillars of curtain wall systems and brace and chord members in roof trusses. In cases where increased axial strength is required, it is popular to use built-up sections, instead of single channel sections. Back-to-back built-up aluminium alloy channel sections as compression members can be used to achieve higher strengths and longer spanning capabilities. In such an arrangement, intermediate fasteners at discrete points along the length can prevent the individual channel sections from buckling independently. However, no investigative research is available on the axial strength of back-to-back built-up aluminium alloy channel sections. This paper presents both experimental and numerical investigations on the behaviour of screw fastened back-to-back built-up aluminium alloy stub columns under compression. In total, the results from 15 axial compression tests are reported. For all test specimens, initial imperfections were measured using a laser scanner. A nonlinear elasto-plastic finite element (FE) model was then developed and validated against the test results. Thereafter, a comprehensive parametric study was conducted using the validated FE model to investigate the effects of modified slenderness, screw number and section thickness on axial strength of back-to-back built-up aluminium alloy channel sections. In total, 232 FE models were analysed. Axial strengths obtained from the tests and FEA were used to assess the performance of current design guidelines offered by the Aluminium Design Manual (ADM), Australian/New Zealand Standards (AS/NZS), Eurocode 9 (EC9), Eurocode3 (EC3) and the American Iron and Steel Institute (AISI) standards. It is shown that the design, in accordance with these standards, is conservative within 20%, with the exception of the allowable stress design method mentioned in AS/NZS (1664.2:1997). The ADM, and AISI & AS/NZS (4600:2018) provide highly accurate predictions; being conservative to the experimental results by 6% and 10% on average, respectively.

Towards a New Analytical Creep Model for Cement-Based Concrete Using Design Standards Approach

Creep properties are determined in design standards by measuring the creep coefficient, noted φ, as a function of time, t, and the age of the concrete at loading, t0. The work aims to study the validity of the analytical models proposed in the most used international standards and to check the possibility of their extension to estimate the creep of recycled aggregates concrete (RAC). A database was built from experimental results available in bibliographic references including 121 creep curves divided into 73 curves for natural aggregates concrete (NAC) and 48 curves for RAC. The comparison between the experimental and predicted values showed a significant dispersion for NAC and RAC. For the remediation of this dispersion, a new analytical model was developed for NAC. The parameters being the conventional creep coefficient, φ0, the power of the ageing function, named α, and βh, which accounts for the relative humidity and the compressive strength in the ageing function, were identified by inverse analysis. It was found that the power of the ageing function is 0.44 and not 0.3, as fixed by Eurocode 2 (EC2). Moreover, new expressions were proposed for φ0 and βh. The presence of recycled aggregates was considered through the equivalent replacement ratio.

Ranking the Seismic Vulnerability of Masonry School Buildings according to the EC8-3 by Using Performance Curves

ABSTRACT A simple methodology for seismic assessment of masonry building, which allows the ranking of the seismic safety of buildings according to principles and rules that are established in Part 3 of the Eurocode 8 (EC8), is presented in this work. This approach uses the concept of “performance curve”, which consists in the representation of all possible performance points (the target displacements of the EC8) associated with a given capacity curve and a response spectrum. This allows a better comparison of the overall seismic behaviour, namely a comparison of the seismic safety associated with all limit states at once, which makes the task of ranking the urgency for seismic retrofitting measures easier. This methodology was used for ranking a set of primary school masonry buildings that still exist in the region of Algarve (Portugal). This work was carried out in the context of the PERSISTAH project.

Experimental and Numerical Investigations on the Rotation Capacity of High-Strength Steel Beams

This work deals with experimental and numerical investigations on the rotation capacity of high-strength steel (HSS) I-girders. The investigation involved 20 three-point bending tests conducted on mainly homogeneous and hybrid high-strength steel girders. The experimental tests have successfully been recalculated numerically considering damage mechanics approaches to model ductile crack initiation. The test of the high-strength steel beams showed that they are able to withstand large rotations with maintaining the plastic-moment capacity. The rotation requirement of Eurocode (EC) 3, doubtful as it might seem, was achieved by 16 of 18 HSS girders.

Optimisation of cold-formed steel beams for best seismic performance in bolted moment connections

Typical thin-walled cold-formed steel (CFS) elements and connections used in portal frames are not generally suitable for moment-resisting frames in high seismic regions due to their low ductility and energy dissipation capacity and inherited susceptibility to local/global instabilities. This study aims to improve the seismic performance of CFS moment-resisting frames by developing a methodology to obtain more efficient bolted moment connections using optimised CFS beams with enhanced non-linear post-buckling behaviour. By taking into account material non-linearity and geometrical imperfection effects, the detailed Finite Element (FE) models of a typical CFS bolted moment connection is developed using ABAQUS software, and then validated based on experimental cyclic test results. Particle Swarm Optimisation (PSO) algorithm is linked to GMNIA ABAQUS FE analysis to optimise CFS bolted moment connections based on either energy dissipation capacity or ductility. To demonstrate the efficiency of the method, connections with five different beam cross-sectional shapes are optimised, and the results are compared with a standard CFS channel section used as a benchmark. The relative dimensions of the cross-sections, the inclination of the lip stiffeners, and the location of triangular intermediate stiffeners are selected as main design variables. To provide practical beam cross-sections, the plate slenderness limit values defined by Eurocode 3 (EC3) along with a range of manufacturing limitations are imposed as design constraints in the optimisation process. It is shown that, for a given plate width and thickness, the proposed optimisation framework results in a considerable (up to 195%) improvement in the energy dissipation capacity and ductility of the CFS bolted moment connections.

Application of Component-Based Mechanical Models and Artificial Intelligence to Bolted Beam-to-Column Connections

Top and seat beam-to-column connections are commonly designed to transfer gravitational loads of simply supported steel beams. Nevertheless, the flexural resistance characteristics of these type of connections should be properly taken into account for design, when a reliable analysis of semi-rigid steel structures is desired. In this research paper, different component-based mechanical models from Eurocode 3 (EC3) and a literature proposal (by Kong and Kim, 2017) are considered to evaluate the initial stiffness (Sj,ini) and ultimate moment capacity (Mn) of top-seat angle connections with double web angles (TSACWs). An optimized artificial neural network (ANN) model based on the artificial bee colony (ABC) algorithm is proposed in this paper to acquire an informational model from the available literature database of experimental test measurements on TSACWs. In order to evaluate the expected effect of each input parameter (such as the thickness of top flange cleat, the bolt size, etc.) on the mechanical performance and overall moment–rotation (M–θ) response of the selected connections, a sensitivity analysis is presented. The collected comparative results prove the potential of the optimized ANN approach for TSACWs, as well as its accuracy and reliability for the prediction of the characteristic (M–θ) features of similar joints. For most of the examined configurations, higher accuracy is found from the ANN estimates, compared to Eurocode 3- or Kong et al.-based formulations.

Comparison of Reliability Based Design (RBD) With Eurocode 2 for A Singly Reinforced Concrete Beam

This research compares the Reliability-Based Design (RBD) method with the Eurocode 2 (EC2) for a singly reinforced concrete beam. Advanced First Order Second Moment (AFOSM) was used and the equation for the ultimate limit state design consideration for Moment of resistance and Applied moment was applied. The parameters which were all functions of the Ultimate load, G were replaced respectively with variables and their derivatives G(x) obtained with being the characteristic strengths of concrete and the yield stress of steel respectively. Given the original vector space and the transformed reduced vector space, the Taylor series was used to expand the reduced vector space and thus reliability index ßx expressed. The procedure was then coded using JAVA to produce the Reliability Index and Probability of failure for respective steel ratio. The required probability index of 3.9 corresponds to 0.048% of the steel ratio. Typical analysis of a singly reinforced beam according to EC2 for b=300mm, h=500mm, d=447mm, cover of 40 mm, gave a steel ratio of 1.31 %. Comparing this to the reliability-based design of 0.048%, the code provision exceeded the RBD output by 2000 times and 63 times the minimum reinforcement requirement by the code.

Loading Capacity Prediction of Rubberized Reinforced Concrete Continuous Deep Beams

Results of fourteen two-span continuous concrete deep beams were presented and discussed in this research. One sample was designed as a reference to be an ordinary reinforced concrete beam (ORC) while thirteen samples were made of rubberized concrete (RRC). The investigated parameters were the shear span/overall depth ratio (a/h) and the rubber replacement ratio with the fine and coarse aggregate. The volumetric replacement ratios were 0, 5%, 10%, 15%, and 20% of the fine aggregate while the coarse aggregate content was kept constant. The same replacement ratios were used for the coarse aggregate. Two shear span/overall depth ratios were used of 1.66 and 1.33.All beams showed the main crack formatted diagonally between the intermediate support and the applied load, indicating a shear failure. The excluded results were compared with those calculated by the strut and tie methods (STM) of the American and Euro codes. It was found that the predicted results of the American and European standards were conservative with mean values of experimental/calculated results of 1.29 and 1.24, respectively. Additionally, the effectiveness factors of the STM suggested by different researchers have been examined. It was found that those approaches were incapable to reflect the effects of the size and amount of rubber used in this study. Therefore, another effective factor was recommended to meet the requirements investigated in the current study. A respectable convergence between the predicted and the experimental results was found in which the mean and coefficient of variation values were 1.004 and 1.158%, respectively.