Reinforcement Ratio Of Beams Research Articles

Shear capacity of PVC-CFRP confined concrete column-RC beam interior joint strengthened with core steel tube

This paper presents an experimental investigation on polyvinyl chloride (PVC)-carbon fiber reinforced polymer (CFRP) confined concrete (PCCC) column-RC beam interior joint strengthened with core steel tube (CST). Thirteen interior joints are designed and tested under low cyclic loading considering the impacts of six variables, such as diameter-thickness ratio of CST, stirrup ratio of joint, axial compression ratio, CFRP strips spacing, reinforcement ratio of beam and reinforcement ratio of column. Distinct shear deformation in joint region finally dominates the failure of specimens. The load-displacement hysteretic curves are relatively full and eventually show inverse S shape, indicating the specimens have considerable seismic behavior and energy dissipation capacity. The yield and peak shear capacities increase as diameter-thickness ratio, stirrup ratio of joint, reinforcement ratio of column or reinforcement ratio of beam increases. Comparatively, the axial compression ratio and CFRP strips spacing exert less influence on shear capacity. Considering the impact of diameter-thickness ratio, stirrup ratio of joint and reinforcement ratio of column, a formula for estimating shear capacity of PCCC column-RC beam interior joints strengthened with CST is proposed and its accuracy is verified by test data.

Shear capacity estimation of core steel tube reinforced PCCC column-beam interior joint under quasi-static load

In this study, the quasi-static tests were conducted on 13 core steel tube (CST) reinforced PVC-CFRP confined concrete (PCCC) column-beam interior joints. Distinct shear failure occurred in all joint specimens. The load-displacement hysteresis curves appeared pinching phenomenon, and the shape of hysteresis loops gradually deformed from shuttle to arch and finally changed to reverse S shape. The overall shape of hysteresis curves were relatively full, demonstrating that the joints had favorable seismic performances and energy dissipation capacity. The strain development law of materials in the joint area in the process of stress was clarified. The increment of joint stirrup ratio ([Formula: see text]), axial compression ratio ([Formula: see text]), column reinforcement ratio ([Formula: see text]) or beam reinforcement ratio ([Formula: see text]) improved the calculated shear capacity of the joints. The calculated shear capacity increased first and then decreased slightly as the diameter-thickness ratio of CST ([Formula: see text]) increased. In comparison, spacing of CFRP strip had little impact on the calculated shear capacity. Additionally, the concrete strength enhancement coefficient ([Formula: see text]) and joint stirrup utilization coefficient ([Formula: see text]) were introduced respectively to modify the shear capacity of concrete and joint stirrups, and a simplified formula for predicting the shear capacity of CST reinforced PCCC column-beam interior joints under quasi-static load was proposed. The predicted results agreed well with the test data.

Prediction of progressive collapse resistance of RC frames using deep and cross network model

Compressive membrane/arch action at small deformations and resistance evolution path at large deformations are two key factors in determining whether an RC frame structure can resist progressive collapse. In this study, two deep learning models based on deep and cross network (DCN) are developed to predict the progressive collapse resistance of RC frames. DCN model I is constructed to predict the compressive membrane/arch action resistance, while DCN model II is developed to predict the resistance displacement curve considering the dynamic effect. 464 records regarding structural collapse were collected through extensive literature review and stringent data filtering. They were randomly divided into 80% and 20% for training and testing the two models, to which the column removal scenario, with or without slab, boundary condition, beam net span, beam section, beam reinforcement ratio, and material property were selected as input features. Moreover, Shapley additive explanations (SHAP) method was introduced to interpret the proposed DCN model. The results indicated that the performance of DCN model I in predicting the compressive membrane/arch action resistance was satisfactory with an MAPE value of 10.66% and an R2 value of 0.9799, respectively, while being more accurate than the existing yield line theory and Park’s compressive arch calculation model. The proposed DCN model II can further capture the evolution of the dynamic resistance of RC frames accurately. The two DCN models have been deployed online to public for application.

ANALISIS STRUKTUR BANGUNAN TERHADAP ELEMEN HORIZONTAL PADA GEDUNG PENYIMPANAN KPK JAKARTA

A storage building is a structure that has specified requirements for usage as a container or location anda high load value. As a result, it is crucial to check or examine the building's structure. There are two separateparts to the building structure, one of which is horizontal. Elements that bear loads working transversely andtransfer the load to a supporting column are known as horizontal elements, sometimes known as bending elements.It is crucial to assess the safety of horizontal elements like beams and slabs since they serve as the floor's bondingand reinforcing frames in superstructures. This final project attempts to assess the shear forces and momentsapplied to the floor slabs and beams, the reinforcement ratio applied to the beams, and the beam deflections thatresult. The presentation in this study makes use of ETABS v.17.0.1 software and secondary data. The 3rd floorhas the largest shear force in the X direction with a value of 59.3292 kN and the largest moment in the X directionwith a value of 128.9298 kN-m, while the 3rd floor has the largest shear force in the Y direction with a value of47.1916 kN and the largest moment in the Y direction with a value of 92.7026 kN-m. According to the result ofETABS v.17.0.1, the beam reinforcement ratio is 0.82 percent, and the maximum deflection permit limit formulauses SNI 2847:2019 to get the permitted deflection value of 25 mm.

Estimasi Dimensi Optimum dan Rasio Tulangan Gedung Hotel Yogyakarta dengan Artificial Neural Network

Cost estimation at the conceptual design stage of a building is necessary because it is considered as a fundamental input in further decision making. This paper presented a neural network method in approximating the optimum dimension and the minimum reinforcement ratio of beams and columns at the conceptual design stage of hotel buildings in Yogyakarta. A group of 27 building variations were prepared as the training data for the set up neural network model. Fourteen empirical formulas were obtained which could be used to estimate the optimum dimension and minimum reinforcement ratio of beams and columns with 5 parameters which consist of soil sites class, beam spans, number of floors, concrete strengths and diameters of the reinforcing bar.

Improvement in Bending Performance of Reinforced Concrete Beams Produced with Waste Lathe Scraps

In this study, the impacts of different proportions of tension reinforcement and waste lathe scraps on the failure and bending behavior of reinforced concrete beams (RCBs) are clearly detected considering empirical tests. Firstly, material strength and consistency test and then ½ scaled beam test have been carried out. For this purpose, a total of 12 specimens were produced in the laboratory and then tested to examine the failure mechanism under flexure. Two variables have been selected in creating text matrix. These are the longitudinal tension reinforcement ratio in beams (three different level) and volumetric ratio of waste lathe scraps (four different level: 0%, 1%, 2% and 3%). The produced simply supported beams were subjected to a two-point bending test. To prevent shear failure, sufficient stirrups have been used. Thus, a change in the bending behavior was observed during each test. With the addition of 1%, 2% and 3% waste lathe scraps, compressive strength escalated by 11.2%, 21.7% and 32.5%, respectively, compared to concrete without waste. According to slump test results, as the waste lathe scraps proportion in the concrete mixture is increased, the concrete consistency diminishes. Apart from the material tests, the following results were obtained from the tests performed on the beams. It is detected that with the addition of lathe waste, the mechanical features of beams improved. It is observed that different proportions of tension reinforcement and waste lathe scraps had different failure and bending impacts on the RCBs. While there was no significant change in stiffness and strength, ductility increased considerably with the addition of lathe waste.

Seismic performance of a ring beam joint connecting FTCES column and RC / ESRC beam with NSC

Fiber-reinforced polymer (FRP) tube-concrete-encased steel (FTCES) composite column shows superior load-bearing capacity, stiffness, deformation capacity and it has excellent corrosion resistance. However, its practical application is very limited due to few experimental and analytical studies on the behaviour of the entire structural system. Indeed, the most challenging part in the structural system is the beam-column joint, which should be carefully designed since it may govern the reliability and stability of the structural system when suffering seismic attack. To fill up this research gap, this paper investigated the seismic performance of a ring beam joint connecting FTCES column and reinforced concrete (RC)/encased steel RC (ESRC) frame beam casted with normal-strength concrete (NSC). A total of four beam-column joints were designed and the effect of ring beam reinforcement ratio, axial force ratio and frame beam type on the seismic behaviour of the joints was studied. Results showed that the proposed joint could provide reliable connection and exhibited favorable seismic performance. Besides, the failure occurred at the location of ring beam, frame beam or the connection between ring beam and frame beam. In addition, the effect of ring beam reinforcement ratio and axial force ratio on the hysteresis curve, skeleton curve, peak load, ductility and (accumulative) dissipated energy was insignificant while the ESRC frame beam could effectively enhance the seismic behaviour of the joint. In the meanwhile, the ESRC frame beam could effectively mitigate the strength and the secant stiffness degradation.

Connection behaviour of through reinforced concrete beam to concrete-filled steel tube column after exposed to heating

The experimental study presented in this paper investigate the post-fire performance of through reinforced concrete (RC) beam to concrete-filled steel tube (CFST) column connection. A total of twelve connection specimens were tested under hogging moment. The connection specimens are grouped into two groups; group A-connections, without fire exposure and group F-connections that are exposed to fire. Two classical connection types were used in this study (type A and B) and one new connection type were proposed herein (type C) by associating additional steel plates to the connection zone. In addition, different beam reinforcement ratios were used. These parameters were considered to evaluate the strength, stiffness, joint classification, ductility, failure modes and strain response of the composite joints. Three failure modes of the connections were found. The connection specimens without fire exposure were found to be a rigid connection. The fire exposure significantly influenced the connection performance, and that influence is varied based on the connection type and beam reinforcement ratio. The proposed connection type is found to have the highest residual capacity among the other connection types. However, a comprehensive analysis of the post-fire behaviour of each connection type is illustrated.

Seismic performance of a ring–beam connecting concrete-filled steel columns with RC frames

The seismic performance of a ring–beam connection system to integrate concrete-filled steel tubular columns and reinforced concrete (RC) frames was studied. Physical experiments on two specimens were conducted under monotonic and cyclic loading. The results showed the connection system had a displacement ductility ratio of 4.68 and an energy dissipation coefficient over 2.0. A finite-element model was established and the numerical and experimental results were compared in terms of skeleton curves and stiffness degradation trends. Parametric studies were then performed to evaluate the effects of the axial compressive force ratio, concrete strength and reinforcement ratio of the ring–beam joint (RBJ) and the reinforcement ratio of the frame beam on the seismic performance of the proposed RBJ connection system. The results showed that an increase in the axial compression ratio or strength of the concrete material improved the initial stiffness and strength of the connection system. The effects of the RBJ reinforcement ratio and the frame beam reinforcement ratio on seismic performance were negligible.

Numerical and analytical investigation on progressive collapse resistance of prestressed precast concrete frame structures

In this paper, a high-fidelity finite element (FE) model was established to numerically investigate the progressive collapse resistance of prestressed precast concrete (PC) frame structures. In particular, discrete beams are applied in the models to consider the contact between transverse bars and energy-dissipated segment of longitudinal bars, which could accurately simulate the damage mode at beam ends of the frames under column removal scenarios. The FE model was validated by simulating a quasi-static pushdown test on two prestressed PC sub-frames with two stories and two spans under the middle column removal scenario in the first floor. The load transfer mechanism of structural component and stress distribution of steel bars and strands in the beams are investigated. Afterwards, parametric studies are carried out to investigate the effects of the length of bonded segment of steel strands, span-depth ratio of beam, longitudinal reinforcement ratio of beam, and construction of shear bars of beam ends on the vertical resistance of the beams in the failed span. The results show that increasing the top reinforcement ratio of beams or setting additional shear reinforcement at joint regions can effectively increase the vertical resistance of the beam at both the compressive arch action (CAA) and tensile catenary action (TCA) stages. Decreasing the length of bonded segment of steel strands could improve the structural ductility in the process of progressive collapse, but cannot influence the variation of vertical resistance of the beams at both CAA and TCA stages. Finally, an analytical method is proposed to calculate the collapse resistant capacity of the prestressed PC frame structure at CAA stage. The method is validated by the results of previous parametric studies.

Experiments and a reverse-curved compressive arch model for the progressive collapse resistance of reinforced concrete frames

The compressive arch action (CAA) is a critical force-transfer mechanism to mitigate the vulnerability of progressive collapse for reinforced concrete frames. To deeply analyze the mechanical behavior of concrete beam-column sub-assemblages under a middle-column-removal scenario, the progressive collapse tests and numerical simulations were accomplished, in which the stress distribution and the force-flow characteristic under CAA were revealed. To accurately evaluate the peak capacity of CAA, a mechanical model of a reverse-curved compressive arch (RCCA) is put forward. The theoretical formulas are derived on the basis of the model, considering both the bending deformation and the axial deformation of the arch. The theoretical calculation results (including the peak capacities and the corresponding displacements) agree well with the experimental results of 20 specimens. Moreover, a parametric analysis on CAA peak capacity is investigated considering the following factors: the axial and rotational restraint stiffness of end supports, the initial connection gap of test setups, the depth-to-span ratio of beams, the concrete strength and the reinforcement ratio of beams. The research results demonstrate that the relative axial (rotational) restraint stiffness should not be less than 1 and the initial connection gap should be less than 1.0 mm to ensure sufficient boundary constraints. According to the parametric analysis results, a simplified formula for CAA peak capacity is established, in which multiple influence coefficients are proposed for the formula. The proposed formula is practical and simple to apply because no iteration or derivation is required, and good calculation accuracy is also verified by 20 specimens. Based on the formulas, the CAA capacities of different column-spacing concrete frames designed with various depth-to-span ratios of beams are compared with the necessary gravity loads. The research results show that the larger the depth-to-span ratio, the greater the bearing capacity margin.

Minimum Flexural Reinforcement Steel Ratios of High‐Strength Concrete Beams

Considering that most studies depend on theoretical equations to determine the minimum reinforcement ratio, only a few studies on this ratio are available. Therefore, a more defined limit should be suggested to design codes by performing additional investigations and experimental studies on this limit. This study examines the behavior of high‐strength concrete (HSC) beams with low reinforcing steel ratios to establish a limit for the lowest flexural reinforcement ratio that will ensure ductility. Experiments were performed on 12 reinforced HSC beams with a concrete compressive strength of 99 MPa, which were divided into three categories depending on their size. Each category comprised four beam reinforcement ratios (0%, 0.13%, 0.33%, and 0.65%), and two main parameters (beam size and reinforcement ratio) were investigated. Furthermore, to ensure flexural failure at the middle‐span, adequate web reinforcing was used in all the beams and tested under a four‐point load until they exhibited failure. Based on regression analysis, an equation was proposed for the rupture modulus of reinforced beams. The findings suggest that, in addition to the yielding strength of the reinforcements and the compressive strength of the concrete, the depth of the beams should be considered when computing the minimum flexural reinforcement of beams.

An experimental comparison of RC beam-column joints incorporating different splice methods in the beam

Reinforcement ratio and bar splice methods have an indubitable effect on the behavior of RC beam-column joints. The present experimental study is focused on evaluating the influence of parameters including reinforcement ratio of beams, method and number of splices on the performance of RC beam-column joints under dynamic loads. To aim this goal, four RC beam-column joints with different numbers of forging (GPW) or mechanical splices (threaded couplers) in the longitudinal bars of beams were tested under cyclic and axial loads applied to beams and columns, respectively. Force-drift hysteresis curves are provided and seismic parameters including displacement ductility, absorbed energy and stiffness are investigated and discussed. More importantly, the results of this study are compared to the results of other specimens available in the literature with similar splice methods but different reinforcement ratio examined under the same loads in order to figure out the effect of reinforcement ratio on the performance of joints with bar splices. Results indicated that the joints incorporating forging method exhibited more appropriate response in comparison to those with threaded couplers by showing more ductility, absorbed energy and stiffness. Moreover, it was observed that reinforcement ratio does not significantly affect stiffness of the specimens with different numbers and types of splices whereas ductility and absorbed energy changes remarkably by changing types and numbers of spliced bars when reinforcement ratio alters.

Flexural behavior of high strength concrete deep beams reinforced with GFRP bars

This paper presents an experimental and numerical study of the flexural behavior of high concrete deep beams reinforced with locally produced glass fiber reinforced polymers (GFRP) bars using high strength concrete (HSC). Both studies were carried out to study the effect of using (GFRP) bars with different ratios of reinforcement and concrete compressive strengths on the behavior of these beams.A total of eight beams, measuring 150 mm wide 500 mm depth and 1800 mm length, were cast, and tested up to failure under two-point loading. The main parameters were the types of reinforcement used, whether steel or GFRP bars. Also, concrete compressive strengths of 50 MPa and 60 MPa were used. In addition, different reinforcement ratios of 0.0033 for steel reinforcement and ratios (0.8, 1.0 and 1.2) of the balanced condition were used. The mid-span deflections, failure loads and GFRP reinforcement strains of the examined deep beams were recorded and compared with each other.The test results revealed that the crack widths and mid-span deflections significantly decreased when using 1.2μb of GFRP reinforcement ratio compared with beams reinforced with steel bars where μb is balanced reinforcement ratio of beam. The decrease in deflection varied between 20%–39.0% for specimens having 50 and 60 MPa respectively, with a significant decrease in the concrete cracks’ widths. Also, the ultimate load slightly increased by 2.5 % and 4.0 % as the concrete strengths increased.A Non-Linear finite element analysis (NLFEA) using ANSYS 2019-R1 was constructed to simulate the flexural behavior of the tested deep beams, in terms of failure load, crack pattern and load deflection behavior. Comparison between the experimental and numerical methods showed good agreement between both results.

A model for predicting load-displacement hysteretic behavior of PVC-CFRP confined concrete column-ring beam interior joints under low cyclic loading

To investigate the seismic behaviors of the column-beam connection, ten PVC-CFRP confined concrete column-ring beam interior joints (PCCC-RBIJs) and one PVC confined concrete column-ring beam interior joint (control interior joint) are designed and five experimental parameters including the CFRP strips spacing, the ring beam reinforcement ratio, the frame beam reinforcement ratio, the ring beam width and the axial compression ratio are considered. Test results show that the PCCC-RBIJs are damaged by shear deformation while the CFRP strips and PVC tubes are not broken. The hysteretic curves of the PCCC-RBIJs are relatively full, indicating that the specimens have high energy dissipation capacity. The peak load and displacement of the PCCC-RBIJs increase as the ring beam reinforcement ratio, the frame beam reinforcement ratio, the ring beam width or the axial compression ratio increases. The descendent segment gradient of the skeleton curves declines with the increase of the ring beam width or the ring beam reinforcement ratio while it enhances with the increase of the frame beam reinforcement ratio or the axial compression ratio. On the basis of experimental research, a simplified skeleton curve calculation formula is proposed by determining the characteristic points of the skeleton curves, and the hysteretic rule of the PCCC-RBIJs is revealed based on the degenerated three fold line load–displacement (P-Δ) hysteretic model. Subsequently, a model for predicting the P-Δ hysteretic behavior of the PCCC-RBIJs is proposed.

Interior Reinforced Concrete Beam-to-Column Joints Subjected to Cyclic Loading: Shear Strength Prediction using Gene Expression Programming

An empirical model, which predicts the shear strength of interior reinforced concrete (RC) joints exposed to cyclic loading, is developed using gene expression programming (GEP). Five main parameters are used to develop the GEP model including concrete compressive strength, joint transverse reinforcement, beam reinforcement ratio, joint aspect ratio, and joint width. A large database including 160 data test points is used to test and train the GEP model. The GEP model is then evaluated using the coefficient of determination (R2). The formulation proposed by ACI-352 is used to predict the shear strength of RC joints. The R-squared values of the ACI and the GEP model are 66% and 87% respectively which indicates that the joint shear strength predicted using the GEP model is closer to the experimental results than that predicted using the ACI-352 formulation.

Revisiting flexural overstrength in RC beam-and-slab floor systems for seismic design and evaluation

Beam flexural overstrength is an important parameter in seismic design and evaluation of reinforced concrete (RC) moment resisting frames. It affects the column-to-beam flexural strength ratio (CBSR) which is a key parameter to avoid unfavorable column-driven mechanisms. In RC beam-and-slab floors, interaction between beam growth and slab panels is of a very complex nature which significantly alters the beam flexural overstrength. Enhancement of beam flexural capacity in slab floor systems depends on several parameters that should be considered on a case-by-case basis. To include some of the effects that were not considered in previous studies due to physical limitations of experimental works and lack of appropriate computational tools, a generic two-by-two bay archetype story model with a beam-and-slab floor system were considered for further investigations by means of numerical modelling. In order to consider the spatial effects of the floor system, several computational models were assembled by changing the span and cross section of beams in terms of depth, width and reinforcement ratio as well as the thickness of slabs to perform a parametric study on beam flexural overstrength ratio. Multilayer nonlinear shell elements were used for finite element modelling of slab panels to account for the kinematic effects of beam elongation along with the restraining effects of the floor slab. According to the results of analyses, variation of positive and negative flexural overstrength ratios of beams at different performance levels were presented for different parameters. Results demonstrate that the flexural overstrength ratio is greatly affected by the level of chord rotation (beam lateral drift or performance level) reinforcement ratio and the type of connection. However, beam-to-slab flexural stiffness ratio as well as beam length are not overly important parameters for flexural overstrength evaluation. This study reveals that, despite code prescriptions, CBSR should not be considered identical for all cases; hence, it should be revisited based on the desired performance level, type of connection and the beam reinforcement ratio.

Effect of Compression Reinforcement Ratio of Beams on the Moment Curvature Relationships

Bu çalışmada betonarme kirişlerde farklı parametre olarak beton sınıfı, boyuna donatı olarak çekme ve basınç donatısı oranlarının moment-eğrilik davranışına etkisi araştırılmıştır. Parametrelerin değerleri değiştirilerek sayısal bir çalışma yapılmıştır. Bu amaçla, 66 adet farklı parametrelere sahip dikdörtgen en-kesitli betonarme kiriş tasarlanmıştır. Kirişlerin davranışı, malzemelerin doğrusal olmayan davranışları göz önüne alınarak moment-eğrilik ilişkililerinden elde edilmiştir. Analizlerde kiriş kesitlerinde beton için sargısız beton modeli kullanılmıştır. Analiz sonuçları kullanılarak akma ve kırılma durumunda moment-eğrilik değerleri, eğrilik sünekliği ve rijitlik oranları elde edilmiştir. Analiz sonuçlarından farklı parametrelerden elde edilen verilerin sonuçları çizelgeler halinde sunulmuş ve sonuçlar değerlendirilmiştir. Dikdörtgen en-kesitli kirişlerin davranışı, eğrilik sünekliği, rijitlik oranları, kirişlerin akma ve kırılma momentlerinin değerlerinden yararlanarak yorumlanmıştır. Betonarme kiriş elemanlarında basınç donatısı oranının artması ile akma momenti, kırılma momenti ve maksimum eğrilik değerleri artmakta fakat akma eğrilik değerleri azalmaktadır. Betonarme kiriş elemanlarında basınç donatı oranının artması ile elemanların süneklikleri ve rijitlikleri artırmaktadır.

Strut-and-tie model for shear strength prediction of RC exterior beam–column joints under seismic loading

Based on the Kupfer failure envelope of concrete, an analytical model called the “interactive strut-and-tie model” (ISTM) for predicting the joint shear capacity of exterior beam–column joints (EBCJs) was formulated and is presented in this study. The ISTM consists of the interaction of the strengths of concrete struts and tension ties, and the strength contributions from shear reinforcements consisting of column ties, intermediate column vertical bars and crossed inclined bars are taken into account. The proposed approach was calibrated and validated using a large dataset of 328 EBCJ test results, covering a broad range of important parameters such as the aspect ratio, axial load ratio, beam reinforcement ratio and horizontal joint reinforcement ratio. Finally, the joint shear strengths computed by the ISTM were also compared against those obtained from state-of-the-art models and were found to have resulted in much more precision and uniformity.

A computationally efficient numerical model for progressive collapse analysis of reinforced concrete structures

Although marked advancements have been achieved to improve the computer power, progressive collapse analysis of large-scale reinforced concrete structures is still time-consuming or even impractical. In this study, a numerical model is proposed for efficient progressive collapse analysis of reinforced concrete structures. Recent advancements that can accurately and efficiently model the mechanical behavior of structural components are incorporated in the numerical model of reinforced concrete structure. The beams/columns, joint regions, and slabs are modeled by enhanced fiber beam element, macrojoint model, and layered shell element, respectively. In this way, the shear failure of beams/columns, failure of joints, and resistance contribution from floor slab can be taken into account for progressive collapse analysis of reinforced concrete structures. A six-story reinforced concrete frame structure is modeled using the approach proposed in this study. The progressive collapse of the structure is analyzed under column removal and direct blast loading scenarios. For comparison purpose, other popularly used finite element models are also adopted to carry out numerical simulations. The proposed model is proven to yield accurate simulation results with the least cost of time among all models. Based on the proposed model, parametric simulations are performed to investigate effective measures to improve the structural resistance to progressive collapse. It is found that increasing longitudinal reinforcement ratio in beams and columns can increase the catenary action capacity, but hardly increases the compressive arch action capacity. Moreover, the steel mesh reinforcement at top layer of slabs plays a significant role in resisting progressive collapse of reinforced concrete structures, which should be considered in design to resist progressive collapse.