scholarly journals DEVELOPMENT OF A SIMPLIFIED SHAKING TABLE TEST METHOD FOR REINFORCED CONCRETE STRUCTURES USING ULTRA SMALL-SCALED MODELS : Reproduction of restoring force characteristics of reinforced concrete members by ultra small-scaled models

2004 ◽  
Vol 69 (584) ◽  
pp. 147-152
Author(s):  
Yuki SAKAI ◽  
Noriko TOKUI ◽  
Yasushi SANADA ◽  
Naruhito YAMAUCHI ◽  
Yoshiaki NAKANO ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Shaking Table Test ◽  
Concrete Structures ◽  
Test Method ◽  
Shaking Table ◽  
Reinforced Concrete Structures ◽  
Restoring Force ◽  
Concrete Members ◽  
Scaled Models ◽  
Force Characteristics

Inelastic Response of R/C Structures with Viscoelastic Braces

1993 ◽  
Vol 9 (3) ◽  
pp. 419-446 ◽  
Author(s):  
R. F. Lobo ◽  
J. M. Bracci ◽  
K. L. Shen ◽  
A. M. Reinhorn ◽  
T. T. Soong
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Concrete Structures ◽  
Elastic Stiffness ◽  
Shaking Table ◽  
Reinforced Concrete Structures ◽  
Inelastic Response ◽  
Viscoelastic Dampers ◽  
Stiffness Properties ◽  
Scaled Models

The addition of viscoelastic braces in structures for vibration reduction has been proposed and implemented in the past decade in metal scaled models of full-scale structures. Viscoelastic braces can provide energy dissipation, while the structure remains elastic. In reinforced concrete structures, the seismic response is usually inelastic, which is often accompanied by permanent deformations and damage. The addition of viscoelastic dampers can dissipate energy at the early stages of cracking of the concrete elements and reduce the development of damage. With proper selection of dampers, this damage can be substantially reduced or even eliminated. However the addition of viscoelastic dampers may stiffen the structure unnecessarily producing increased inertial forces and base shears when subjected to seismic motion. The quantification of the influence of viscous damping and elastic stiffness properties of dampers during the inelastic response of reinforced concrete structures is the subject of this investigation. Models for analysis of inelastic response with damage indexing for reinforced concrete structures that include viscoelastic braces are developed and calibrated using experimental data produced by shaking table tests. These models are then used to determine the variation of expected damage in the presence of damping and quantify the hysteretic energy dissipation along with the damping energy.

scholarly journals Detection of Reinforcement Corrosion in Reinforced Concrete Structures by Potential Mapping: Theory and Practice

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Gino Ebell ◽  
Andreas Burkert ◽  
Jürgen Mietz
Keyword(s):  
Reinforced Concrete ◽  
Influencing Factors ◽  
Stress Measurement ◽  
Concrete Structures ◽  
German Society ◽  
Theory And Practice ◽  
Test Method ◽  
Reinforced Concrete Structures ◽  
Reinforcing Steel ◽  
Potential Mapping

Electrochemical potential mapping according to guideline B3 of DGZfP (German Society for Nondestructive Testing) is a recognized technique for the localization of corroding reinforcing steels. In reinforced concrete structures the measured potentials are not necessarily directly linked to the corrosion likelihood of the reinforcing steel. The measured values may be significantly affected, different from, e.g., stress measurement, by different influences on the potential formation at the phase boundary metal/concrete itself as well as the acquisition procedure. Due to the complexity of influencing factors there is a risk that the results are misinterpreted. Therefore, in a training concept firstly the theoretical basics of the test method should be imparted. Then, frequently occurring practical situations of various influencing factors will be made accessible to the participants by a model object specially designed for this purpose. The aim is to impart profound knowledge concerning the characteristics of potential mapping for detecting corrosion of reinforcing steel in order to apply this technique in practice as reliable and economical test method.

Shaking Table Tests With Large Test Specimens of Seismically Isolated FBR Plants: Part 2—Damage Test of Reinforced Concrete Wall Structure

2009 ◽  
Author(s):  
Satoru Inaba ◽  
Takuya Anabuki ◽  
Kazutaka Shirai ◽  
Shuichi Yabana ◽  
Seiji Kitamura
Keyword(s):  
Reinforced Concrete ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Wall Structure ◽  
Shaking Table Tests ◽  
Concrete Wall ◽  
Restoring Force ◽  
Seismically Isolated ◽  
Rubber Bearings

This paper describes the dynamic damage test of a reinforced concrete (RC) wall structure with seismic isolation sysytem. It has been expected that seismically isolated structures are damaged in sudden when the accelerations of the structures exceed a certain level by hardening of the rubber bearings. However, the response behavior and the damage mode have not been observed by experimental test yet. So, shaking table tests were carried out at “E-Defense”, equipping the world’s largest shaking table, located at Miki City, Hyogo prefecture, Japan. The specimen was composed of an upper structure of 600 ton by weight and six lead-rubber bearings (LRBs) of 505 mm in diameter which provide both stiffness and hysteretic damping. The upper structure consisted of a RC mass and four RC walls with counter weight. The RC wall structure was designed so that the damage of the RC wall occurred between the shear force at the hardening of the rubber bearings and that at their breaking. The dimensions of the RC wall were 1600 × 800 × 100 mm (B × H × t). The reinforcement ratios were 2.46% in vertical by D13 (deformed reinforcing bar, 13 mm in diameter) and 1.0% in horizontal by D10. The shaking table test was conducted consecutively by increasing the levels up to 225% of tentative design earthquake motion. Consequently, because of the increase of the structural response by the hardening of the rubber bearings, the damage of the wall structure with seismic isolation system suddenly happened. In addition, the preliminary finite element analysis simulated the test results fairly well, which were the restoring force characteristics, the crack patterns of the RC wall structure and such.

INFLUENCE OF CONCRETE COMPOSITION ON THE CORROSIVE STATE OF THE STEEL ARMATURES AND DURABILITY OF REINFORCED CONCRETE STRUCTURES

2019 ◽  
pp. 33-39
Author(s):  
Petro Koval ◽  
Vladimir Zelenovskiy
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
The State ◽  
Test Method ◽  
Design Stage ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Reinforcing Steel ◽  
Concrete Composition ◽  
Corrosion State

The influence of the composition of the concrete mixture on the state of reinforcing steel as the main problem of corrosion of reinforced concrete structures is considered. The main attention is paid to the need for individual and mandatory consideration of the influence of the properties of additives to concrete on the passivation of reinforcing steel. The purpose of conducting studies to determine the effect of concrete composition on the state of reinforcing steel is to analyze the causes of corrosion of reinforcement, determine the influence of the environment, apply appropriate prevention of this phenomenon and use methods to determine the corrosion state at the design stage of building structures for which reinforced concrete is used. The composition of concrete, in addition to the standard set in various quantitative combinations (cement, gravel, sand, water) today it is advisable to use special additives. Due to their correct and proportional application, you can create a mixture with significantly improved characteristics: with increased frost resistance, strength, durability, with accelerated or delayed setting of the mixture, etc. Nevertheless, you should not forget that the individuality of the composition of additives could affect the ability of concrete to passivate reinforcing steel. It is possible to eliminate the possibility of reducing the passivation of concrete by testing reinforced concrete samples for its protective properties in relation to the reinforcement. The test method is based on the passivation of reinforcing steel in an alkaline environment and consists in evaluating the protective effect of a sample of concrete in relation to a sample of steel reinforcement by comparing data obtained with a change in potential depending on changes in the density of electric current passing through the sample. The issue of quality and durability of reinforced concrete structures, both technically and economically, is attracting increasing attention of builders. It is obvious that in most cases an increase in the initial cost of manufacturing the structure and its reliable protection is economically justified, if this allows reducing the number and cost of repairs during operation. Keywords: reinforcement, corrosion, concrete, reinforced concrete, concrete additive, concrete composition, corrosion state of reinforcement, durability of reinforced concrete structures.

New Water-Based Anti-Corrosion Chemical Materials in Engineering Repairing

2011 ◽  
Vol 287-290 ◽  
pp. 249-252
Author(s):  
Wei Chen ◽  
Chao Jun Xiao ◽  
Zhi Jian Xu ◽  
Xian Ning Jiang ◽  
Kai Fu Zhou ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Epoxy Resin ◽  
Environmental Protection ◽  
Concrete Structures ◽  
Raw Material ◽  
Reinforced Concrete Structures ◽  
Concrete Members ◽  
Water Based ◽  
Chemical Materials

The environmental protection water-based grafted whole propyl epoxy resin latex(AOW-201) as a basic raw material of the interface penetrant, waterproof pressure and anti-cracking putty, and anti-corrosion coatings and water-based with rust anti-corrosion paint,that are used for reinforced concrete members repair works.Therefore,that is a type of reinforced concrete structures worthy of restoration works to promote the application of new anti-corrosion chemical materials.

scholarly journals Prepared experimental study for durability verification of FRP reinforced concrete members

2021 ◽  
Vol 1209 (1) ◽  
pp. 012055
Author(s):  
S Blaho ◽  
K Gajdošová
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Concrete Structures ◽  
High Strength ◽  
Bending Test ◽  
Reinforced Concrete Structures ◽  
Reinforced Polymers ◽  
Concrete Members ◽  
Four Point Bending

Abstract Major advantage of fibre reinforced polymers (FRPs) is their high strength and low weight to strength ratio. These are also the main reasons for a choice for this material in the process of design of reinforced concrete structures. Since there is no corrosion of FRP, this reinforcement could be strongly recommended for concrete reinforcement in aggressive environment. Till today there is no sufficient knowledge of long-term behaviour of FRP-reinforced concrete structures. Design codes give low utilization capacity of FRP materials and are not supposed to be correct according to the real behaviour in a few experiments of last decades. Reduction factors limit the mechanical properties in the range from 0.95 for CFRP to 0.5 for GFRP. In the paper there is presented a prepared and today realized long-term experimental study based on four point bending test on simply supported concrete beams reinforced with GFRP reinforcement.

scholarly journals CRITICAL DEPTH OF NORMAL CRACKS IN REINFORCED CONCRETE BEAMS OF RECTANGULAR CROSS-SECTION

2013 ◽  
Vol 19 (4) ◽  
pp. 583-590 ◽  
Author(s):  
Vidmantas Jokūbaitis ◽  
Linas Juknevičius
Keyword(s):  
Reinforced Concrete ◽  
Stress State ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Analytical Data ◽  
Concrete Structures ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structures ◽  
Concrete Members ◽  
Section Shape

The evaluation of stress state of longitudinal tensile reinforcement is highly important while examining the technical state of under-reinforced concrete structures. The appearance of yield stress in tensile reinforcement could be treated as the start of incipient failure of the flexural structure. The state of tensile reinforcement of flexural reinforced concrete structures could be examined by observing the properties of normal cracks. This paper presents the analysis of the relationship between various parameters of a normal crack during its development. Some elements of fracture mechanics are used for analysis of stress state in flexural reinforced concrete members. The analytical data are compared to the experimental results, and the adjustment functions are proposed for flexural beams of certain cross section shape, dimensions and reinforcing ratio.

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