scholarly journals Experimental Study of Composite Hollow RC Column under Uniaxial Compressive Load

2019 ◽  
Vol 9 (3) ◽  
pp. 373
Author(s):  
Deokhee Won ◽  
Seungjun Kim ◽  
Jihye Seo ◽  
and Young-Jong Kang

This paper presents an experimental study of the behavior of a steel-composite hollow reinforced concrete (RC) column under concentric loading. The effects of important variables, such as concrete strength, inner tube thickness, hollow ratio, column diameter, and transverse reinforcement space, are presented in this study. The failure of composite hollow RC columns is characterized by the formation of an inclined shear sliding plane. When the column had a highly confined effect, the inclination of the shear sliding plane was 45°. This study shows that the required performance is achieved when the splice providing transverse reinforcement is fully bonded. Furthermore, the inner tube experiences buckling failure after reaching its maximum strength. The steel-composite hollow RC column with high-strength concrete (HSC) has lower ductility and toughness compared to a column with normal-strength concrete (NSC).

2020 ◽  
Vol 10 (2) ◽  
pp. 642 ◽  
Author(s):  
Luís Bernardo ◽  
Sérgio Lopes ◽  
Mafalda Teixeira

This article describes an experimental program developed to study the influence of longitudinal prestress on the behaviour of high-strength concrete hollow beams under pure torsion. The pre-cracking, the post-cracking and the ultimate behaviour are analysed. Three tests were carried out on large hollow high-strength concrete beams with similar concrete strength. The variable studied was the level of longitudinal uniform prestress. Some important conclusions on different aspects of the beams’ behaviour are presented. These conclusions, considered important for the design of box bridges, include the influence of the level of prestress in the cracking and ultimate behaviour.


2002 ◽  
Vol 29 (2) ◽  
pp. 191-200 ◽  
Author(s):  
M Alavi-Fard ◽  
H Marzouk

Structures located in seismic zones require significant ductility. It is necessary to examine the bond slip characteristics of high strength concrete under cyclic loading. The cyclic bond of high strength concrete is investigated under different parameters, including load history, confining reinforcement, bar diameter, concrete strength, and the rate of pull out. The bond strength, cracking, and deformation are highly dependent on the bond slip behavior between the rebar and the concrete under cyclic loading. The results of cyclic testing indicate that an increase in cyclic displacement will lead to more severe bond damage. The slope of the bond stress – displacement curve can describe the influence of the rate of loading on the bond strength in a cyclic test. Specimens with steel confinement sustained a greater number of cycles than the specimens without steel confinement. It has been found that the maximum bond strength increases with an increase in concrete strength. Cyclic loading does not affect the bond strength of high strength concrete as long as the cyclic slip is less than the maximum slip for monotonic loading. The behavior of high strength concrete under a cyclic load is slightly different from that of normal strength concrete.Key words: bond, high strength, cyclic loading, bar spacing, loading rate, failure mechanism.


2013 ◽  
Vol 671-674 ◽  
pp. 1860-1864 ◽  
Author(s):  
Thomas Vincent ◽  
Togay Ozbakkloglu

It is well established that external confinement of concrete with fiber reinforced polymer (FRP) sheets results in significant improvements on the axial compressive behavior of concrete. This understanding has led to a large number of experimental studies being conducted over the last two decades. However, the majority of these studies have focused on normal strength concretes (NSC) with compressive strengths lower than 55 MPa, and studies on higher strength concretes have been very limited. This paper presents the results of an experimental study on the compressive behavior of FRP confined high- and ultra high-strength concrete (HSC and UHSC) with average compressive strengths of 65 and 100 MPa. A total of 29 specimens were tested under axial compression to investigate the influence of key parameters such as concrete strength and method of confinement. All specimens were cylindrical, confined with carbon FRP and were 305 mm in height and 152 mm in diameter. Results obtained from the laboratory testing were graphically presented in the form of axial stress-strain relationships and key experimental outcomes are discussed. The results of this experimental study indicate that above a certain confinement threshold, FRP-confined HSC and UHSC exhibit highly ductile behavior. The results also indicate that FRP-wrapped specimens perform similar to concrete-filled FRP tube (CFFT) specimens at ultimate condition, however notable differences are evident at the transition region when comparing stress-strain curves.


2005 ◽  
Vol 8 (2) ◽  
pp. 101-116 ◽  
Author(s):  
Sumei Zhang ◽  
Lanhui Guo ◽  
Zaili Ye ◽  
Yuyin Wang

This paper presents an experimental study of the separated behavior of short ( L/H=3) high strength concrete-filled rectangular hollow section (RHS) tubes concentrically loaded in compression to failure. A total of 50 specimens were tested. Experimental results showed that the concrete strength influenced the failure pattern of the specimen. The height-to-breadth ratio of the rectangular tube (varying from 1.0 to 1.6) had no evident influence on the ultimate bearing capacity of the specimen. Then based on the experimental results, a numerical separation method was successfully used to separate the compressive load carried by the steel tube and the core concrete. The equivalent One-Dimensional nonlinear stress-strain models of the steel and the confined concrete were suggested, which can be used to determine the overall behavior of the high strength concrete-filled RHS tubes. The stress-strain models have been used to numerically analyze the behavior of high strength concrete-filled RHS tubes. The numerical results are compared with the experimental results and they agreed well with each other.


2019 ◽  
Vol 23 (4) ◽  
pp. 614-629
Author(s):  
Shaohua Zhang ◽  
Xizhi Zhang ◽  
Shengbo Xu ◽  
Xingqian Li

This study reports the cyclic loading test results of normal-strength concrete-filled precast high-strength concrete centrifugal tube columns. Seven half-scale column specimens were tested under cyclic loads and axial compression loads to investigate their seismic behavior. The major parameters considered in the test included axial compression ratio, filled concrete strength, and volumetric stirrup ratio. The structural behavior of each specimen was investigated in terms of failure modes, hysteresis behavior, bearing capacity, dissipated energy, ductility, stiffness degradation, drift capacity, and strain profiles. Test results revealed that the concrete-filled precast high-strength concrete centrifugal tube column exhibited good integral behavior, and the failure modes of all columns were ductile flexural failures. Lower axial compression ratio and higher volumetric stirrup ratio resulted in more satisfactory ductile performance. In contrast, the filled concrete strength has a limited influence on the structural behavior of concrete-filled precast high-strength concrete centrifugal tube columns. Based on the limit analysis method, the calculation formula for the bending capacity of the concrete-filled precast high-strength concrete centrifugal tube column was developed, and the results predicted from the formulas were in good agreement with the experiment results.


2021 ◽  
Vol 309 ◽  
pp. 01194
Author(s):  
Vemundla Ramesh ◽  
Chitla Raju

Due to the application of advanced material technology, concrete with high compressive strength is currently produced and used in many countries. This type of concrete can be produced by micro-silica and superplasticizers as well as applying good quality control procedures. The use of high-strength concrete (HSC) in building construction is becoming popular because it has many advantages such as increased strength and stiffness, reduced size of concrete sections, improved resistance to creep and drying shrinkage, and material durability. Therefore we can use high strength concrete (HSC) in columns and normal strength concrete (NSC) for beams & floor sections. Thus this study will investigate the performance of 8 storey tall buildings in ZoneIV for medium grade soil with varying high strength concrete (HSC) normal strength concrete (NSC) subjected to far-field ground motions scaled to collapse of the structure using varying grades (M20, M25, M30, M35, M40, and M50) of concrete strength subjected to seismic ground motions scaled to collapse of the structure using a linear static method and this will be achieved through analytical modeling and analysis using ETABS2018 software.


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