scholarly journals Influence of effective width of flange on calculation and reinforcement dimensioning of beam of reinforced concrete frame

2021 ◽  
Vol 20 (2) ◽  
pp. 041-056
Author(s):  
Maciej Tomasz Solarczyk
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Frame ◽  
Cross Sectional ◽  
Concrete Frame ◽  
Definition Of ◽  
Effective Flange Width ◽  
The Impact ◽  
T Beam

The article analyses the impact of modeling the cross-section of two-nave and two-storey reinforced concrete frame with dimensions: 18.0 m × 32.0 m as a bars on the results of bending moments, the value of elastic deflection and dimensioning of reinforcement due to bending. Six options were considered: a beam as a rectangular section and five T-beam variants with different definition of effective flange width. The differences in obtained results were commented. Conclusions useful for the designing of reinforced concrete structures were presented. The procedure for determining the effective flange width in the context of PN-EN 1992-1-1:2008 and PN-B 03264:2002 standards with a commentary on the use of effective flange width in calculations and construction of reinforcement in reinforced concrete structures were described. Brief description of determining the reinforcement due to bending according to simplified method given in PN-EN 1992-1-1:2008 was presented. In addition, the standard formula for determining the minimum cross sectional area of reinforcement (9.1N) in PN-EN 1992-1-1:2008 with a proposal for its strict determination for the T-beam with a flange in the tensile zone was analyzed.

Study on Damage Identification for Reinforced Concrete Structures Based on Wavelet Transform

2011 ◽  
Vol 94-96 ◽  
pp. 1505-1510 ◽  
Author(s):  
Xiao Yu Miao ◽  
She Liang Wang ◽  
Yu Jiang Fan
Keyword(s):  
Wavelet Transform ◽  
Reinforced Concrete ◽  
Damage Identification ◽  
Concrete Structures ◽  
Spatial Location ◽  
Reinforced Concrete Structures ◽  
Test Model ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Reinforced Concrete Frame Structures

Reinforced concrete structures are prone to damage during their service lifetime caused by factors such as the effect of overload, ground motions, and other actions. Undetected damage may lead to structural failures. Early detection of damage and timely repairs can prevent catastrophic failure and ensure regular service of structures. As a result, a so-called delimitation wavelet-transform search method, based on the characteristic of multi-resolution of wavelet transform, is presented in this paper for on-line damage identification of reinforced concrete structures. One possible advantage of this method is that the damage temporal and spatial location can be detected rapidly and efficiently. Further research is carried out with numerical simulation of a structure test model to study the storied damage detection and localization of reinforced concrete frame structures under seismic actions. The analyzing result is compared with that observed in a simulated earthquake vibration stand test. Good agreement is obtained and it verifies the effectiveness and validity of the method proposed in this paper.

Numerical and Experimental Analysis of the Nonlinear Response of Reinforced Concrete Frame Structure from Seismic Effects

2017 ◽  
Vol 738 ◽  
pp. 205-214
Author(s):  
Ivana Veghova
Keyword(s):  
Reinforced Concrete ◽  
Material Properties ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Frame ◽  
Capacity Spectrum Method ◽  
Standard Material ◽  
Concrete Frame ◽  
Spectrum Method ◽  
Capacity Spectrum

Using capacity spectrum method was analyzed frame reinforced concrete structures. Capacity spectrum method has been used to analyse frame reinforced concrete structures. Geometry, material properties and reinforced cross sections were designed by experimental tested model of reinforced concrete frame joints in the scale of 1:1. The results were compared with the results of the analysis of the structure of the same geometrical characteristics but of standard material properties of concrete and steel.

scholarly journals Selected Aspects of Computer Modeling of Reinforced Concrete Structures

2016 ◽  
Vol 62 (1) ◽  
pp. 51-64 ◽  
Author(s):  
M. Szczecina ◽  
A. Winnicki
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Bending Moment ◽  
Material Model ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Frame ◽  
Material Constants ◽  
Applied Model ◽  
Concrete Frame ◽  
Angle Fracture

Abstract The paper presents some important aspects concerning material constants of concrete and stages of modeling of reinforced concrete structures. The problems taken into account are: a choice of proper material model for concrete, establishing of compressive and tensile behavior of concrete and establishing the values of dilation angle, fracture energy and relaxation time for concrete. Proper values of material constants are fixed in simple compression and tension tests. The effectiveness and correctness of applied model is checked on the example of reinforced concrete frame corners under opening bending moment. Calculations are performed in Abaqus software using Concrete Damaged Plasticity model of concrete.

A Study for Evaluating Local Damage to RC Panels Subjected to Oblique Impact: Part 1 — A Study for Evaluating Local Damage Caused by Oblique Impact of Rigid Projectiles

2017 ◽  
Author(s):  
Yoshimi Ohta ◽  
Akemi Nishida ◽  
Haruji Tsubota ◽  
Yinsheng Li
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Oblique Impact ◽  
Reinforced Concrete Structures ◽  
Local Damage ◽  
Normal Impact ◽  
Impact Tests ◽  
Oblique Impacts ◽  
New Formula ◽  
The Impact

Many empirical formulae have been proposed to evaluate the local damage to reinforced concrete structures caused by the impact of rigid projectiles. Most of these formulae have been derived based on impact tests perpendicular to the target structures. To date, few impact tests oblique to the target structures have been conducted. The purpose of this study is to propose a new formula for evaluating the local damage caused by oblique impacts based on experiments and simulations. The new formula is derived by modifying an empirical formulation for normal impact and the agreement with results of past oblique impact tests is discussed.

Seismic response of reinforced concrete frame subassemblages — a Canadian code perspective

1989 ◽  
Vol 16 (5) ◽  
pp. 627-649 ◽  
Author(s):  
Patrick Paultre ◽  
Daniel Castele ◽  
Suzanne Rattray ◽  
Denis Mitchell
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Concrete Structures ◽  
Poor Performance ◽  
Reinforced Concrete Beam ◽  
Test Results ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Slab Width ◽  
Cyclic Loading Tests

The 1984 CSA standard for the design of concrete structures for buildings provided new seismic design and detailing requirements for concrete structures. Full-scale, reversed cyclic loading tests of reinforced concrete beam–slab–column subassemblages were carried out to investigate the seismic performance of frame structures designed with the latest Canadian code. The test results indicate the importance of including the influence of slab reinforcement in computing the beam capacity as well as the need to carefully design the joint regions for shear. The test results indicate the excellent performance of frame components designed with K = 0.7 (R = 4.0) and the poor performance of those designed and detailed with K = 2.0 (R = 1.5). The performance of subassemblages designed with K = 1.3 (R = 2.0) depends on the column to beam strength ratio and on the shear strength of the joints. Models to predict the flexural response as well as the shear response of key elements are described and the role of the spandrel beam in limiting the effective slab width is explained. Key words: seismic design, reinforced concrete, detailing, structures, codes.

scholarly journals COMBINED EFFECT OF CARBONATION AND CHLORIDE AGGRESSION: DEG-RADATION OF REINFORCED CONCRETE STRUCTURES

2018 ◽  
Author(s):  
L.V. KIM ◽  
E.E. SHALYI ◽  
S.N. LEONOVICH ◽  
N.A. BUDREVICH
Keyword(s):  
Reinforced Concrete ◽  
Ph Value ◽  
Concrete Structures ◽  
Chloride Concentration ◽  
Protective Layer ◽  
Sharp Decrease ◽  
Threshold Concentration ◽  
Steel Reinforcement ◽  
Reinforced Concrete Structures ◽  
Cross Sectional

Corrosion reinforcement marine hydraulic structures due to chloride aggression and carbonization of concrete leads to a sharp decrease in the safety of the structure. The steel reinforcement will be subjected to a so-called depassivation process, once the chloride concentration on surface exceeds a certain threshold concentration, or the pH value in the protective layer of concrete decreases to a threshold value due to carbonation. Electrochemical reactions begin to occur with the formation of corrosion products with the penetration of oxygen on the steel reinforcement surface. This leads to cracking of the protective layer of concrete. It should also be taken into account that, due to corrosion mechanisms, the cross-sectional area of the reinforcement also decreases. The article suggests a method for predicting the complex degradation of reinforced concrete structures, taking into account various mechanisms of corrosion wear, which will allow developing effective ways to improve the durability and maintainability of structures operated in the marine environment.

scholarly journals Calculation of damage RC constructions according to deformation model

2020 ◽  
Vol 2020 (2) ◽  
pp. 99-106
Author(s):  
Yaroslav Blikharskyy ◽  
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Physical And Mechanical Properties ◽  
Reinforced Concrete Beams ◽  
Core Material ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
The Impact

This article presents results of a theoretical study of reinforced concrete beams with damaged reinforcement. The change of micro-hardness of a reinforcing rebar’s with a diameter of 20 mm of A500C steel in the radial direction is investigated and the thickness of the heat-strengthened layer is established. It is established that the thickness of the thermo-strengthened steel layer of the reinforcing bar with a diameter of 20 mm of A500C is approximately 3 mm. It is shown that the strength characteristics of this layer are on 50% higher compared to the core material of the rebar, while the plasticity characteristics are lower. The aim of the work is to determine the strength and deformability of reinforced concrete structures without damaging the reinforcement and in case of damage. Determining the impact of changes in the physical characteristics of reinforcement on the damage of reinforced concrete structures, according to the calculation to the valid norms, in accordance with the deformation model. To achieve the goal of the work, theoretical calculations of reinforced concrete beams were performed according to the deformation model, according to valid norms. This technique uses nonlinear strain diagrams of concrete and rebar and is based on an iterative method. According to the research program 3 beam samples were calculated. Among them were undamaged control sample with single load bearing reinforcement of ∅20 mm diameter – BC-1; sample with ∅20 mm reinforcement with damages about 40% without changes in the physical and mechanical properties of reinforcement – BD-2 and sample with ∅20 mm reinforcement with damages about 40% with changes in the physical and mechanical properties of reinforcement – BD-3. The influence of change of physical and mechanical characteristics of rebar’s on bearing capacity of the damaged reinforced concrete beams is established.

scholarly journals Impact of impurities of local construction materials on the bearing capacity of the concrete used in structures in Burundi

Vestnik MGSU ◽  
2021 ◽  
pp. 1357-1362
Author(s):  
Emmanuel Mikerego ◽  
Nestor Niyonzima ◽  
Jean Claude Ntirampeba
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Concrete Structures ◽  
Construction Materials ◽  
Reinforced Concrete Structures ◽  
Ordinary Concrete ◽  
Average Decrease ◽  
Local Construction ◽  
The Impact ◽  
Mixing Water

Introduction. The article is about an assessment of the impact of impurities contained in the local construction materials on the mechanical characteristics of the concrete used in reinforced concrete structures in Burundi. Materials and methods. The methodology of the study consisted in varying the quantity of impurities for the manufactu­ring of the concrete experimental cubic samples. The grain sizes of the studied ordinary concrete were in the favourable zones according to the recommended granulometry for standard concretes. Simulation of impurities was made by adding in the mixing water solid particles taken from a local rock called “red earth”. The particles were composed by (24 %) of clays, (38 %) of silts and (38 %) of sands. As for the used cement in this study, it was the type CEM I (32.5). The quantities of impurities were expressed in grams per litre of mixing water (g/l) and were varying from (0 g/l) to (100 g/l) with a step of (20 g/l). The prepared experimental concrete samples were stored in the laboratory of materials at the University of Burundi and were subjected to compression testing under hydraulic press after 28 days. Results. The impact of impurities consisting of (24 %) of clays, (38 %) of silts and (38 %) of sands is identified. Each increase of (20 g) of impurities in a litre of mixing water induces an average decrease of (4 %) on the compressive strength and the Young’s modulus for an ordinary concrete. Conclusions. The impact of impurities contained in the local construction materials used in the manufacturing of the concrete for reinforced concrete structures in Burundi is studied. Each increase of (20 g) of impurities in a litre of mixing water induces an average decrease of (4 %) on the compressive strength and the Young’s modulus of an ordinary concrete. For Burundi, a curve for the approximation of the bearing capacity of the concrete used in reinforced concrete structures according to the quantity of impurities contained in the local construction materials was established. Hence, it is advisable to start by the specification of the quantity of impurities contained in the construction materials before making the concrete for reinforced concrete structures in order to predict the mechanical performances of the concrete used in reinforced concrete structures.

ANALYSIS OF DURABILITY OF REINFORCED CONCRETE STRUCTURES OF BRIDGES ACCORDING TO THEIR TYPICAL DESIGNS

2020 ◽  
Vol 264 (4) ◽  
pp. 58-63
Author(s):  
Larysa Bodnar ◽  
◽  
Serhii Zavhorodnii ◽  
Serhii Stepanov ◽  
Vitalii Yastrubinetskyi
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Highway Bridges ◽  
Reinforced Concrete Structures ◽  
Bridge Management ◽  
Bridge Span ◽  
Standard Design ◽  
Standard Designs ◽  
Bridge Spans ◽  
The Impact

Thousands of bridges built in the 20th century are operated on Ukrainian roads. In the limited funding of the road industry of Ukraine, the age of highway bridges is constantly increasing, the number of defects in structures is growing. The largest number of defects is concentrated in the bridge spans. The main part of the bridge spans consists of prefabricated reinforced concrete beams, manufactured in factories of reinforced concrete structures according to standard designs developed in the middle of the last century. As a result of long-term operation of bridges, the shortcomings of these designs which reduce the service life of bridge spans and bridges in general are revealed. The systematic approach is required to study this process. The Analytical Expert Bridge Management System (AESUM) operates in the Ukravtodor system. This software complex accumulates all the information on the results of inspections (certification) of bridges on public roads. The special module AESUM – a database of standard designs of bridge spans which is constantly updated was developed to make decisions on repair works taking into account the features of structures on standard designs, to store this information in a single complex, in electronic form. Standard designs of reinforced concrete bridge spans built and operated on the roads of Ukraine are considered, and a comparative analysis of the features of these designs is performed taking into account the impact on the safety of bridge operation, their main features and shortcomings are given. The concept of rank of the standard design on durability is entered. A formula for estimating the durability of bridge span of a standard design using this concept is proposed. The analysis of durability of bridge span is performed. A number of problematic standard designs have been identified. Keywords: road bridge, standard designs, durability.

CONCRETING AND EARLY HARDENING PROCESSES IN MONOLITHIC REINFORCED CONCRETE STRUCTURES / PROCESAI, VYKSTANTYS BETONAVIMO IR PRADINIO KIETĖJIMO METU GELŽBETONINĖSE MONOLITINĖSE KONSTRUKCIJOSE

2012 ◽  
Vol 4 (2) ◽  
pp. 67-75
Author(s):  
Vigantas Antanas Žiogas ◽  
Svajūnas Juočiūnas ◽  
Violeta Medelienė ◽  
Giedrius Žiogas
Keyword(s):  
Reinforced Concrete ◽  
Structure Formation ◽  
Structural Strength ◽  
Concrete Strength ◽  
Time Moment ◽  
Concrete Structures ◽  
Concrete Mixture ◽  
Industrial Building ◽  
Reinforced Concrete Structures ◽  
The Impact

The exploitation time and reliability of monolithic reinforced concrete structures largely depend on concreting technology and process influence during concreting and early setting stages. Different types of cracks in monolithic reinforced concrete structures appear due to internal and external effects. Cracks appear when the technology of structure concreting is damaged, when formwork is removed during the further setting and structures loaded period. In order to avoid micro and macro cracks in monolithic structures, it is important to measure the particular setting time moment and technological process moment when stresses that exceed the permissible values appear in concrete. The article analyses the processes that appear when horizontal, sloping and vertical monolithic reinforced concrete structures are concreted. The analysis of concrete mixture pressure on formwork is performed. The pressure which is calculated according to different countries’ methodology is different: the smallest pressure is obtained calculating according to the British recommendations, and the largest pressure is obtained according to French CIB recommendations. In Lithuania, it is recommended to follow the German DIN 18218 standard. The balance conditions of concrete mixture concreting on slope surface are described. The main concreting technology parameters and their interaction are analysed; the speed, intensity and time of continuous concreting technology are presented. When the process of continuous concreting is performed, it is necessary to evaluate the interaction and values of parameters properly. Methodical theoretical calculation is presented. Practical solutions for industrial building construction applying the modern sliding formwork technology are presented. The impact of cement type, superplasticizers and temperature over the concrete mixture mobility, changes, fresh concrete structural strength and concrete setting kinetics are analysed. The main characteristics of the initial setting — the beginning of structure formation, when concrete mixture turns into concrete state — is analysed applying the ultrasonic method. The beginning of structure formation influences the regulated time of concrete mixture laying and compaction. The requirements for structural strength (permissible strength limits) and concreting rate (formwork movement) of freshly formed concrete are set when the construction is performed applying the continuous concreting technology method. The analysis is implemented performing the construction of cylindrical sludge tank with slipping formwork. While performing the analysis during concreting, it was stated that the concrete setting kinetics corresponds to the sludge tank concreting rate. The analysis performed after concreting and in 28 days of hardening revealed that there are no surface defects or cracks, and concrete strength exceeds the required sludge tank design strength. Santrauka Monolitinių gelžbetoninių statinių konstrukcijų eksploatacijos trukmė ir patikimumas daugiausia priklauso nuo betonavimo technologijos ir procesų poveikių betonavimo bei pradinio kietėjimo metu. Straipsnyje nagrinėjami procesai, vykstantys betonuojant horizontaliąsias, nuožulniąsias ir vertikaliąsias monolitines gelžbetonines konstrukcijas. Atlikta betono mišinio slėgio į formas analizė. Tiriami pagrindiniai betonavimo technologijos parametrai, analizuojamas jų ryšys, pateikiamas nepertraukiamo betonavimo technologijos betonavimo greitis, intensyvumas, trukmė. Atlikti teoriniai skaičiavimai ir siūlomi praktiniai sprendimai pramoninių statinių statybai, naudojant šiuolaikinę slankiųjų klojinių technologiją. Ištirta cemento tipo, superplastiklių, temperatūros įtaka šviežiai suformuoto betono struktūriniam stipriui ir betono kietėjimo kinetikai. Nustatyti reikalavimai šviežiai suformuoto betono struktūriniam stipriui, betonavimo greičiui (klojinių kėlimui), vykdant statybą nepertraukiamos betonavimo technologijos metodu. Tyrimai pritaikyti vykdant cilindrinio dumblo pūdytuvo statybą slankiaisiais klojiniais.

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