Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Behavior of Spirally Reinforced High Strength Concrete Columns Under Axial Loading
Author: Behavior of Spirally Reinforced High Strength Concrete Columns Under Axial Loading
Author: David L. MontgomeryPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
An experimental investigation was conducted to study the behavior of spirally reinforced high strength concrete (HSC) columns subjected to axial compression loading. The main objective of the experiment was to investigate the effects of the volumetric ratio of spiral steel, the spiral spacing, the specimen size and the concrete strength on the strength and ductility performance of confined concrete. Behavior of the cover concrete, spiral reinforcement steel, and longitudinal reinforcing bars were also investigated to gain insight into the overall behavior of HSC columns. A total of 32 spirally reinforced HSC columns were tested, including ten 254 mm diameter columns with concrete strength f'c of 69.7 Mpa, nine 203 mm diameter columns with concrete strength f'c of 69.7 MPa, and thirteen 203 mm diameter columns with concrete strength f 'c of 89.8 MPa. Overall height of each specimen was four times the diameter. All of the specimens were reinforced longitudinally with five deformed reinforcement bars and laterally by various amounts of spiral reinforcement. An increase in the volumetric ratio of spiral steel resulted in increases in the strength and ductility of confined HSC, with the improvements in ductility being more pronounced. Reductions in spiral spacing resulted in improved strength and ductility of confined HSC when the volumetric ratio of spiral steel was sufficiently large. Increases in concrete strength were found to result in decreases in the peak strength enhancement, axial strain at peak strength, spiral stress at peak strength, and deformability of the specimens. Larger diameter columns achieved better participation of the cover concrete shell and had larger strengths at low axial strains. Cover concrete began spalling at lower concrete strengths and at earlier axial strains than expected in the columns with f'c of 89.8 MPa.
Experimental Evaluation of the Behavior of Spirally-reinforced High-strength Concrete Columns
Author: Annette M. PieroniPublisher:
ISBN:
Category : Columns, Concrete
Languages : en
Pages : 169
Book Description
Spirally-reinforced High-strength Concrete Columns
Author: Salvador Martinez MoralesPublisher:
ISBN:
Category : Columns, Concrete
Languages : en
Pages : 602
Book Description
Behavior of High Strength Concrete Columns Under Axial Load and Cyclic Flexure
Author: Dharmendra Vallabhbhai ShahPublisher:
ISBN:
Category : Columns, Concrete
Languages : en
Pages : 364
Book Description
Behavior of Light Weight High Strength Concrete Columns Under Axial Load and Cyclic Flexure
Author: Sandeep Navinchandra PatelPublisher:
ISBN:
Category : Columns, Concrete
Languages : en
Pages : 264
Book Description
Behavior of High-Strength Concrete Columns
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The use of high-strength concrete for bridges and high-rise buildings become popular due to development in concrete technology and availability of various types of mineral and chemical admixtures. High-strength concrete could lead to smaller member sizes for compression members and therefore provide considerable savings associated with material costs and reduction of dead loads. However, Most of the current design codes, such as AASHTO-LRFD Bridge Specifications, are still based on tests conducted using normal-strength concrete. Many studies indicate that the behavior of columns with high-strength concrete is different from that of normal-strength concrete. The experimental phase of this investigation consists of thirty two rectangular and twenty four circular columns subjected to concentric and eccentric loading conditions to investigate the behavior of high-strength concrete columns. The main variables considered in this study were concrete strength ranging from 7.9 to 16.5 ksi, shape of cross section, and longitudinal and transverse reinforcement ratios. Using the test results of this study and other researches in literature, the dissertation provides design equation to predict the capacity of high-strength concrete columns with tie and spiral reinforcements subjected to concentric and eccentric loading conditions up to 18 ksi. The research also proposes a new stress-strain relationship of high-strength concrete confined with spiral reinforcements.
Flexural Behavior of Reinforced Concrete Columns with Five-spiral Reinforcement Under Cyclic and Eccentric Axial Loading
Author: 留明誠Normal-strength and High-strength Concrete Columns Under Cyclic Axial Load and Biaxial Moment
Author: Mehdi ZareiPublisher:
ISBN:
Category :
Languages : en
Pages : 151
Book Description
The technique of using Carbon Fiber Reinforced Polymer (CFRP) materials to repair and strengthen various concrete members has become popular in the structural retrofitting field as an effective way to enhance the strength and ductility of concrete members due to its superior mechanical properties. In this study a method was introduced to study the behavior of concrete columns with and without CFRP jackets under constant axial load and variable lateral load. The lateral load was applied monotonically and cyclically. To predict the behavior of concrete columns under monotonic and cyclic compressive loadings, a computer code was developed to produce the moment-curvature diagram for concrete sections. The moment-curvature diagram was then input in SAP2000 to study the behavior of reinforced concrete columns. The result of this analysis was found to correlate with experimental data well. The behavior of high-strength concrete (HSC) columns having various properties and subjected to a variety of loading conditions has been the topic of considerable investigation. Of particular significance in this area is the behavior of HSC columns under cyclic compressive load with bidirectional eccentricity. For the experimental investigation, tests of six square slender HSC columns were conducted under stroke control to achieve both ascending and descending branches of the load-deformation curves. Analysis of HSC columns subjected to cyclic axial compression with bidirectional eccentricity was approached from the standpoint of a three-dimensional problem. A computer program based on the extended finite segment method and accounting for geometrical nonlinearity has been proposed here to predict the load-deflection curves of HSC columns under cyclical loading. The HSC stress-strain relationship obtained by parametric study and experimental investigation into the behavior of concrete under cyclical load history has been incorporated into the numerical procedure. The presented computer analysis results have been compared with the experimental data, and a satisfactory agreement was attained for both the ascending and descending branches of the load-deformation curves.
Strength of High Strength Concrete Columns Under Eccentric Compression
Author: R. H. Basappa SettyPublisher:
ISBN:
Category : Columns, Concrete
Languages : en
Pages : 130
Book Description
The research work involved a study of behaviour and strength of eccentrically loaded High Strength Concrete columns. The research comprised experimental and analytical components. With regard to experimental work, twelve columns were manufactured and tested to failure. All columns were rectangular in cross-section with 300 mm x 100 mm as dimensions. The test specimens were loaded about the minor axis. The ratio of longitudinal reinforcement was either 1.47% (4 - 12 mm diameter bars) or 2.2% (6 - 12 mm diameter bars). The lateral reinforcement was in the form of rectangular closed ties made of 6 mm wires (W6). The spacing of ties was generally 50 mm, but, was decreased to 30 mm, at either ends to avoid premature failure.