Reliability of beams designed in accordance with Brazilian codes

This paper presents an investigation on the safety of structural elements submitted to pure bending, produced in reinforced concrete, in steel and steel-concrete composites, and designed according to Brazilian codes NBR8681:2003, NBR6118:2007 and NBR8800:2008. The study allows a comparison of the relative safety of beams produced with these materials and designed using these codes. Comparative studies between the performances of different materials are difficult to find in the published literature. The present study shows that reliability indexes for reinforced concrete beams are satisfactory; however, results for steel beams are below limit values established in international design standards. Reliability indexes found herein for steel-concrete composite beams are intermediate to concrete and steel beams.

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Laboratory Fast Corrosion Test of Plain Steel Bars in Concrete Beams

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.535-537.1803 ◽

2012 ◽

Vol 535-537 ◽

pp. 1803-1806

Author(s):

Shun Bo Zhao ◽

Peng Bing Hou ◽

Fu Lai Qu

Keyword(s):

Reinforced Concrete ◽

Concrete Beams ◽

Numerical Models ◽

Concrete Strength ◽

Reinforced Concrete Beams ◽

Uniform Corrosion ◽

Pure Bending ◽

Accelerated Corrosion ◽

Steel Bars ◽

Bending Length

An experimental study was carried out to examine the non-uniform corrosion of plain steel bars in reinforced concrete beams partially placed in 5% sodium chloride solution under conditions of accelerated corrosion. 4 reinforced concrete beams with different concrete strength were made. The crack distributions of the beams due to pre-loads and expansion of corrosion product, and the sectional corrosion characteristics of plain steel bars are described in detail. The sectional area loss relating to mass loss and change along pure bending length of the beams are discussed. These can be used as the basis of test for further studies to build the numerical models of serviceability of corroded reinforced concrete beams.

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Effect of Plastering Layer on Corrosion Resistances of Reinforced Concrete Beams

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.a1220.109119 ◽

2019 ◽

Vol 9 (1) ◽

pp. 1390-1393

Keyword(s):

Corrosion Resistance ◽

Reinforced Concrete ◽

Concrete Beams ◽

Point Load ◽

Reinforced Concrete Beams ◽

Experimental Program ◽

Structural Elements ◽

Accelerated Corrosion ◽

Total Mass Loss ◽

Load Arrangement

Reinforced concrete structures are subjected to deterioration due to many factors such as corrosion of reinforcing steel. Ultimate strengths of structural elements can be greatly affected by these deteriorating factors. There are numerous methods and techniques used to protect these structural elements. The mortar layer (Plastering) is considered the first defense line against all the deteriorating factors. The main goal of this research is to investigate to what extent the plastering layer can protect reinforced concrete beams against corrosion. The aim of the experimental program is to study the effect of plastering layer on corrosion resistance of reinforced concrete beams. Four reinforced concrete beams (1002001100 mms) and four Lollypop specimens (cylinders 100200 mms) were tested and described as follows: • A beam and a lollypop specimen without any plastering layer (control). • A beam and a lollypop specimen with traditional plastering layer (cement + sand + water). • A beam and a lollypop specimen with modified plastering (traditional plastering + waterproof admixtures). • A beam and a lollypop specimen with painted and modified plastering layer (traditional plastering + waterproof admixtures + external waterproof paint). These eight specimens were subjected to corrosion using accelerated corrosion technique, after that the four beams were tested in flexure under three point load arrangement while the four lollypops were used to calculate the total mass loss due to accelerated corrosion. The test results were used to figure out the effect of plastering layer on corrosion resistance of RC beams.

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Research on the Efficiency of Composite Beam Application in Multi-Storey Buildings

Sustainability ◽

10.3390/su12208328 ◽

2020 ◽

Vol 12 (20) ◽

pp. 8328 ◽

Cited By ~ 1

Author(s):

Tomas Kinderis ◽

Mindaugas Daukšys ◽

Jūratė Mockienė

Keyword(s):

Reinforced Concrete ◽

Fire Resistance ◽

Composite Beam ◽

Concrete Beams ◽

Residential Building ◽

Reinforced Concrete Beam ◽

Composite Beams ◽

Reinforced Concrete Beams ◽

Assessment Criteria ◽

Floor Structure

Over the past decade, several types of composite slim floor constructions have been used in multi-storey buildings in Lithuania. In order to study the efficiency of composite beam application in steel-framed multi-storey buildings, Thorbeam (A1), Deltabeam (A2), slim floor beam (A3) and asymmetric slim floor beam (A4) were chosen and evaluated according to nine assessment criteria (beam cost (K1), initial preparation on site (K2), installation time (K3), complexity of installation technology (K4), labour costs (K5), fire resistance (K6), load bearing capacity (K7), beam versatility (K8), and availability of beams (K9)). First, the significance of the rating criteria was selected and the order of the ranking criteria was obtained (K1˃K7˃K3˃K6˃K4˃K5˃K2˃K8˃K9) by means of a survey questionnaire. Second, the beams were ranked according to the points given by the questionnaire respondents as follows: 160 points were given to A2, 144 points to A1, 129 points to A4, and 111 points to A3. Deltabeam is considered to be the most rational alternative of the four beams compared. Calculations done using the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) analysis method revealed that composite beam A2 was the best slim floor structure alternative for an eight-storey high-rise commercial residential building frame, A1 ranked second, A4 ranked third, and A3 ranked fourth. In addition, the four composite beams were compared to a reinforced concrete beam (A5) according to three assessment criteria (beam cost including installation (C1), beam self-weight (C2) and fire resistance (C3)). Deltabeam was found to be efficient for use as a slim floor structure in a multi-story building due to having the lowest cost, including installation, and self-weight, and the highest fire resistance compared to other composite beams studied. Although Deltabeams are 1.4 times more expensive than reinforced concrete beams, including installation costs, they save about 2.5% of the building’s height compared to reinforced concrete beams.

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RESULTS OF EXPERIMENTAL RESEARCH OF REINFORCED CONCRETE BEAMS RESISTANCE IN THE ZONE OF SHEAR BENDING

URBAN CONSTRUCTION AND ARCHITECTURE ◽

10.17673/vestnik.2017.04.5 ◽

2017 ◽

Vol 7 (4) ◽

pp. 25-31

Author(s):

Valery B. FILATOV ◽

Vladislav O. GORYNTSEV ◽

Valery P. BINDER

Keyword(s):

Reinforced Concrete ◽

Concrete Beams ◽

Longitudinal Section ◽

Reinforced Concrete Beams ◽

Calculation Methods ◽

Design Standards ◽

Testing Data ◽

Failure Loads ◽

Experimental Values ◽

Shear Bending

The results of an experimental study of the strength and stress-strain state of reinforced concrete beams in the zone of shear bending are presented. The study was carried out on samples with a small percentage of longitudinal section reinforcement. The technique of testing, data on the rigidity and crack resistance of test specimens under loading, the nature of their destruction are presented. Comparison of experimental values of failure loads with calculated values obtained by the methods of domestic and foreign design standards is performed. It is shown that the empirical basis of the calculation methods limits the range of satisfactory correspondence between the calculated and experimental values of the strength of inclined sections of reinforced concrete beams under the action of shear forces. The conclusion is made about the need to improve the design models to ensure the constructive safety of design solutions.

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Composite design method for masonry walls on concrete beams

Canadian Journal of Civil Engineering ◽

10.1139/l83-062 ◽

1983 ◽

Vol 10 (3) ◽

pp. 337-349 ◽

Cited By ~ 1

Author(s):

B. Stafford Smith ◽

L. Pradolin

Keyword(s):

Reinforced Concrete ◽

Concrete Beams ◽

Design Method ◽

Design Procedure ◽

Bending Moment ◽

Reinforced Concrete Beam ◽

Masonry Wall ◽

Reinforced Concrete Beams ◽

Steel Beams ◽

Arch Action

This paper describes a design method for structures consisting of a vertically loaded masonry wall supported by a reinforced concrete beam, taking account of the composite tied-arch action of the wall and beam. Experimental results have shown that the behaviour of walls on reinforced concrete beams is similar enough to that of walls on steel beams to allow the development of a design procedure for the former using similar principles to that for walls on steel beams. Therefore, the design approach is based on the assumption of triangular distributions of vertical stress at the wall–beam interface, where the length of the distributions are a function of the beam-to-wall relative stiffness. In the design method the beam flexural stiffness is designed to give an adequate distribution of the interface stress so that the maximum stress in the wall does not exceed allowable limits. The beam is also designed with flexural and shear reinforcement sufficient to resist the bending moment, tie force, and shear forces applied by the normal and shear interface loading. Experimental evidence as well as analytical results are cited to support the assumptions and the resulting design method.

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Stability Analysis of High-Rise Buildings by Altering the Beam Members: A Review

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.38450 ◽

2021 ◽

Vol 9 (10) ◽

pp. 501-507

Author(s):

Ankur Nagar

Keyword(s):

Reinforced Concrete ◽

Composite Beam ◽

Concrete Beams ◽

Tall Buildings ◽

Reinforced Concrete Beams ◽

Steel Beams ◽

Lateral Loads ◽

Rigid Frame ◽

Lateral Rigidity ◽

The Impact

Abstract: For buildings larger than 15 to 20 floors, a system with a clean rigid frame is not adequate because it does not provide the required lateral rigidity and causes excessive deflection of the building. These requirements are met in two ways. By introducing the effective section such as beam, column etc in to the structure. This increases the stability and rigidity of the structure, and also limits the requirement for deformation. Now days the composite beam is also used for tall buildings. The Paper present the short summery report of use of various beam elements in building to get the effective out comes to sustained under the lateral forces response. The literature review focus on the impact on the building analysis by altering the Beam Members. Reinforced Concrete Beams, Steel Beams, and Composite Beams. The articles reviewed the concept on introducing the alternating beam in the structure are effective and achieve the higher resisting capacity against the lateral loads. Keywords: Reinforced Concrete Beams, composite beam, Steel Beams, tall buildings, deformation, stability

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Influence of the percentage of reinforcement by unstressed rebar on the deformability of pre-stressed RC beams

Production Engineering Archives ◽

10.30657/pea.2021.27.28 ◽

2021 ◽

Vol 27 (3) ◽

pp. 212-216

Author(s):

Yaroslav Blikharskyy ◽

Jacek Selejdak ◽

Taras Bobalo ◽

Roman Khmil ◽

Mykhailo Volynets

Keyword(s):

Reinforced Concrete ◽

Concrete Beams ◽

Bending Moment ◽

Reinforced Concrete Beams ◽

Practical Significance ◽

Pure Bending ◽

Static Loads ◽

Steel Bars ◽

Periodic Profile

Abstract This article presents the materials of deformability studies of pre-stressed steel-concrete beams reinforced with a package of reinforcement with different ratio of tape and rebar in the pure bending moment zone. The aim of the research was determination of the reinforcement percentage influence, for pre-stressed reinforced concrete beams reinforced with a package of reinforcement on their deformability. Also, the aim was to evaluate the effectiveness of using pre-stressed rebar in combined reinforcement. The practical significance of the experimental research is to study the deformability in pre-stressed bending elements with external tape and rebar reinforcement, taking into account the influence of different ratios of reinforcement areas within the combined reinforcement and development of proposals for such structures` calculation and design. The scientific novelty of the research is in obtaining the deformability characteristics of reinforced concrete beams reinforced with a package of reinforcement (tape and steel bars with periodic profile) with different ratios in the case of static loads` action.

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Numerical Investigations on Behavior of Strengthened RC Beams with CFRP under Combined Bending and Torsion

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.857.120 ◽

2020 ◽

Vol 857 ◽

pp. 120-129

Author(s):

Abdul Muttalib I. Said ◽

Qais H. Al-Shemmari

Keyword(s):

Reinforced Concrete ◽

Ultimate Load ◽

Concrete Beams ◽

Numerical Study ◽

Reinforced Concrete Beams ◽

Loading Conditions ◽

Pure Bending ◽

Numerical Work ◽

Numerical Investigations ◽

Cfrp Sheets

The numerical investigations were carried out to study the behavior of reinforced concrete beams strengthened by CFRP under different loading conditions (pure bending and combined bending and torsion). The numerical work included analysis of eight experimentally tested beams of rectangular cross-section dimensions of (160×240) mm and (2600) mm length keeping the area of the ordinary reinforcement constant for all beams. The following parameters were taken into consideration, twisting to bending moment ratio (T/M) and CFRP strengthening arrangement. The analyzed beams are divided into four groups. Each group consists of two beams; the first beam is without CFRP strengthening, the other beam is strengthened with CFRP. Each beam is loaded to a different loading conditions (pure bending, T/M=0.5, T/M=1.0, T/M=2.0). The CFRP sheets were attached externally to the beam. Analysis results were analyzed based on influence of CFRP on ultimate load and vertical mid-span deflection. According to the numerical study, it was found that all strengthening arrangements of CFRP sheets exhibited a significant increase in ultimate strength. The three-dimensional (3D) finite element model (FEM) utilized in present work is capable to simulate the behavior of externally strengthened reinforced concrete beams by CFRP. Full bond connections (no slip) are assumed between the CFRP sheets and surface of concrete. The comparison between the numerical and the experimental results declared the validity of the numerical analysis where the range of the (Pexp./PANSYS) ratio in ultimate load was from 0.847 to 1.157. The general behavior of the (FEM) shows good agreement with the test results from the experimentally tested beams.

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Flexural Behaviors of RC Beams Strengthened with Post-Poured UHTCC Layer

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.150-151.6 ◽

2010 ◽

Vol 150-151 ◽

pp. 6-9

Author(s):

Shi Lang Xu ◽

Nan Wang

Keyword(s):

Reinforced Concrete ◽

Concrete Beams ◽

Load Capacity ◽

Three Dimensional ◽

Close Correlation ◽

Composite Beams ◽

Reinforced Concrete Beams ◽

Rc Beams ◽

Strength Failure ◽

Three Dimensional Finite Element

For studying the effectiveness of externally pouring Ultra High Toughness Cementitious Composites (UHTCC) in improving the flexural behaviors of existing reinforced concrete beams, four-point bending tests were conducted up to failure on seven RC beams and strengthening beams. The flexural strength, failure mode and crack propagation of composite beams were investigated. The results showed that pouring UHTCC on the bending surface of reinforced concrete beams properly to improve the ductility and load capacity of composite beams. It was also found that UHTCC layer restricted the development of cracks in upper concrete and dispersed them into multiple fine cracks effectively. Compared with post-poured concrete, UHTCC was more suitable for working together with reinforcement. The load-deflection plots obtained from three-dimensional finite-element models (FEMs) analyses were compared with those obtained from the experimental results, which showed close correlation.

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