Triaxial test results of high-strength concrete subjected to cyclic loading

2003 ◽  
Vol 55 (4) ◽  
pp. 321-329 ◽  
Author(s):  
W. P. Lokuge ◽  
J. G. Sanjayan ◽  
S. Setunge
Keyword(s):  
Cyclic Loading ◽  
Triaxial Test ◽  
High Strength Concrete ◽  
High Strength ◽  
Test Results ◽  
Strength Concrete

Beam-column behaviour of steel tubes filled with high strength concrete

1994 ◽  
Vol 21 (2) ◽  
pp. 207-218 ◽  
Author(s):  
Helmut G. L. Prion ◽  
Jens Boehme
Keyword(s):  
Cyclic Loading ◽  
High Strength Concrete ◽  
High Strength ◽  
Test Results ◽  
Loading Test ◽  
Steel Tubes ◽  
Strength Concrete ◽  
Main Emphasis ◽  
Thin Steel ◽  
Current Code

The results of an investigation into the behaviour of thin-walled steel tubes filled with high strength concrete are presented. The main emphasis is placed on the level of ductility that can be achieved, considering the fact that neither high strength concrete nor thin steel tubes are individually able to absorb significant amounts of energy under cyclic loading. Results of 26 tests on specimens with a diameter of 152 mm and a wall thickness of 1.7 mm, filled with concrete of characteristic compressive strength ranging between 73 and 92 MPa, are reported. Load combinations on the specimens range from pure axial compression, through various combinations of axial load and bending, to pure bending. Three specimens were subjected to cyclic loading. Test results are compared with design models that are used in current code specifications. Key words: steel tubes, concrete, composite, beam-column, beam, column, experimental.

Effects of Nano-CaCO3 on the Compressive Strength and Microstructure of High Strength Concrete in Different Curing Temperature

2011 ◽  
Vol 121-126 ◽  
pp. 126-131 ◽  
Author(s):  
Qing Lei Xu ◽  
Tao Meng ◽  
Miao Zhou Huang
Keyword(s):  
Compressive Strength ◽  
Low Temperature ◽  
High Strength Concrete ◽  
High Strength ◽  
Curing Temperature ◽  
Test Results ◽  
Strength Concrete ◽  
Calcium Nitrite ◽  
Orientation Index ◽  
Early Strength

In this paper, effects of nano-CaCO3 on compressive strength and Microstructure of high strength concrete in standard curing temperature(21±1°C) and low curing temperature(6.5±1°C) was studied. In order to improve the early strength of the concrete in low temperature, the early strength agent calcium nitrite was added into. Test results indicated that 0.5% dosage of nano-CaCO3 could inhibit the effect of calcium nitrite as early strength agent, but 1% and 2% dosage of nano-CaCO3 could improve the strength of the concrete by 13% and 18% in standard curing temperature and by 17% and 14% in low curing temperature at the age of 3days. According to the XRD spectrum, with the dosage up to 1% to 2%, nano-CaCO3 can change the orientation index significantly, leading to the improvement of strength of concrete both in standard curing temperature and low curing temperature.

Effect of Chopped Basalt Fiber on the Fresh and Hardened Properties of Fly Ash High Strength Concrete

2014 ◽  
Vol 567 ◽  
pp. 381-386 ◽  
Author(s):  
Nasir Shafiq ◽  
Muhd Fadhil Nuruddin ◽  
Ali Elheber Ahmed Elshekh ◽  
Ahmed Fathi Mohamed Salih
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
High Strength Concrete ◽  
Basalt Fiber ◽  
High Strength ◽  
Progressive Increase ◽  
Test Results ◽  
Strength Concrete ◽  
Hardened Properties ◽  
Chopped Basalt Fiber

In order to improve the mechanical properties of high strength concrete, HSC, several studies have been conducted using fly ash, FA. Researchers have made it possible to achieve 100-150MPa high strength concrete. Despite the popularity of this FAHSC, there is a major shortcoming in that it becomes more brittle, resulting in less than 0.1% tensile strain. The main objective of this work was to evaluate the fresh and hardened properties of FAHSC utilizing chopped basalt fiber stands, CBFS, as an internal strengthening addition material. This was achieved through a series of experimental works using a 20% replacement of cement by FA together with various contents of CBFS. Test results of concrete mixes in the fresh state showed no segregation, homogeneousness during the mixing period and workability ranging from 60 to 110 mm. Early and long terms of compressive strength did not show any improvement by using CBFS; in fact, it decreased. This was partially substituted by the effect of FA. Whereas, the split and flexural strengths of FASHC were significantly improved with increasing the content of CBFS as well as the percentage of the split and flexural tensile strength to the compressive strength. Also, test results showed a progressive increase in the areas under the stress-strain curves of the FAHSC strains after the CBFS addition. Therefore, the brittleness and toughness of the FAHSC were enhanced and the pattern of failure moved from brittle failure to ductile collapse using CBFS. It can be considered that the CBFS is a suitable strengthening material to produce ductile FAHSC.

Properties of High Strength Fibre Reinforced Concrete Using Ultra Fine Slag

2016 ◽  
Vol 857 ◽  
pp. 183-188
Author(s):  
C. Mohan Lal ◽  
Vontary Sai Srujan Reddy
Keyword(s):  
High Strength Concrete ◽  
Steel Fibre ◽  
High Strength ◽  
Target Strength ◽  
Partial Replacement ◽  
Fibre Reinforced Concrete ◽  
Test Results ◽  
Design Requirement ◽  
Split Tensile Strength ◽  
Strength Concrete

High strength concrete has become a design requirement in recent years due to increase in number of infrastructure projects. This paper presents the effect of incorporating Ultra Fine Slag (UFS) and steel fibre to obtain high strength concrete. To achieve target strength of about 80 MPa, it is proposed to the replacement of cement of 10%, 20% and 30% with UFS and incorporating 0.5% and 1.0% fibre in concrete. An experimental investigation is carried out to find the mechanical properties of the concrete. From the test results, it was observed that a compressive strength of 95 MPa was achieved at 30% replacement of cement with UFS and 1.0% fibre content. In addition, there was a significant improvement in split tensile strength and flexural strength of the concrete. This study demonstrates that a high strength concrete can be obtained from partial replacement of cement with UFS and addition of steel fibre.

Bond behavior of high strength concrete under reversed pull-out cyclic loading

2002 ◽  
Vol 29 (2) ◽  
pp. 191-200 ◽  
Author(s):  
M Alavi-Fard ◽  
H Marzouk
Keyword(s):  
Cyclic Loading ◽  
Bond Strength ◽  
High Strength Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Displacement Curve ◽  
Bond Slip ◽  
Strength Concrete ◽  
Pull Out ◽  
Normal Strength

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.

scholarly journals Cyclical Behavior of Concrete-Encased Composite Frame Joints with High Strength Concrete

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Lei Zeng ◽  
Zhenkun Cui ◽  
Yunfeng Xiao ◽  
Siqian Jin ◽  
Yuanyuan Wu
Keyword(s):  
Cyclic Loading ◽  
High Strength Concrete ◽  
Joint Strength ◽  
Concrete Strength ◽  
Outer Part ◽  
High Strength ◽  
Crack Pattern ◽  
Experimental Program ◽  
Strength Concrete ◽  
Composite Frame

This paper presents an application of high strength concrete to concrete-encased composite frame building based on an experimental program. The work emphasized joints behavior under reverse cyclic loading caused by earthquakes to provide information for seismic design. To investigate the internal mechanisms and seismic performance, cyclic loading tests were carried out on five half-scale interior joints. Two design variables were addressed in the research: concrete strength and axial column load. Frame joints performance including crack pattern, failure mode, deformation, ductility, strain distribution, and energy dissipation capacity was investigated. It was found that all joint specimens behaved in a manner with joint panel shear failure. Using high strength concrete increased the joint strength and had relatively little effect on the stiffness and ductility. The axial column load helped the joint strength by better mobilizing the outer part of the joint, but it had an obvious influence on the ductility and energy-dissipating capacity, which can be improved by providing enough transverse reinforcement. A typical crack pattern was also provided which can well reflect mechanical character and damage process. This research should contribute to the future engineering applications of high strength concrete to concrete-encased composite structure.

Seismic behaviour of prestressed high-strength concrete piles under combined axial compression and cyclic horizontal loads

2018 ◽  
Vol 22 (5) ◽  
pp. 1089-1105 ◽  
Author(s):  
Xizhi Zhang ◽  
Sixin Niu ◽  
Jia-Bao Yan ◽  
Shaohua Zhang
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
High Strength Concrete ◽  
High Strength ◽  
Element Model ◽  
Test Results ◽  
Seismic Behaviour ◽  
Strength Concrete ◽  
Concrete Piles ◽  
Concrete Pile

In order to simulate the seismic behaviour of the prestressed high-strength concrete piles under working state, six full-scale prestressed high-strength concrete piles were tested under combined axial compression and cyclic horizontal loads. Different axial compression levels and prestressing levels of prestressed tendons were studied in this test programme. The failure mode, bending resistance, displacement ductility, stiffness degradation and energy dissipation of the prestressed high-strength concrete piles under different loading scenarios were measured and analysed. Test results indicated that the axial compression ratio and prestressing level of prestressed tendon significantly influenced the seismic performance of prestressed high-strength concrete piles. Theoretical models were developed to predict cracking, yielding and ultimate bending resistances of the prestressed high-strength concrete pile under combined compression and bending. Finite element model was also developed to simulate the ultimate strength behaviour of the prestressed high-strength concrete pile under combined compression and flexural bending. The accuracies of the theoretical and finite element model were checked through validations of their predictions against the reported test results.

scholarly journals A Study on the Thermal Properties of High-Strength Concrete Containing CBA Fine Aggregates

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1493 ◽  
Author(s):  
In-Hwan Yang ◽  
Jihun Park
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Ultrasonic Velocity ◽  
High Strength Concrete ◽  
High Strength ◽  
Unit Weight ◽  
Test Results ◽  
Strength Concrete ◽  
Fine Aggregates

The thermal conductivity of concrete is a key factor for efficient energy consumption in concrete buildings because thermal conductivity plays a significant role in heat transfer through concrete walls. This study investigated the effects of replacing fine aggregates with coal bottom ash (CBA) and the influence of curing age on the thermal properties of high-strength concrete with a compressive strength exceeding 60 MPa. The different CBA aggregate contents included 25%, 50%, 75%, and 100%, and different curing ages included 28 and 56 days. For concrete containing CBA fine aggregate, the thermal and mechanical properties, including the unit weight, thermal conductivity, compressive strength, and ultrasonic velocity, were measured. The experimental results reveal that the unit weight and thermal conductivity of the CBA concrete were highly dependent on the CBA content. The unit weight, thermal conductivity, and compressive strength of the concrete decreased as the CBA content increased. Relationships between the thermal conductivity and the unit weight, thermal conductivity and compressive strength of the CBA concrete were proposed in the form of exponential functions. The equations proposed in this study provided predictions that were in good agreement with the test results. In addition, the test results show that there was an approximately linear relationship between the thermal conductivity and ultrasonic velocity of the CBA concrete.

scholarly journals Multigene Genetic Programming for Estimation of Elastic Modulus of Concrete

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Alireza Mohammadi Bayazidi ◽  
Gai-Ge Wang ◽  
Hamed Bolandi ◽  
Amir H. Alavi ◽  
Amir H. Gandomi
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Genetic Programming ◽  
High Strength Concrete ◽  
Elastic Moduli ◽  
High Strength ◽  
Test Results ◽  
Strength Concrete ◽  
Multigene Genetic Programming ◽  
Compressive Strength Test

This paper presents a new multigene genetic programming (MGGP) approach for estimation of elastic modulus of concrete. The MGGP technique models the elastic modulus behavior by integrating the capabilities of standard genetic programming and classical regression. The main aim is to derive precise relationships between the tangent elastic moduli of normal and high strength concrete and the corresponding compressive strength values. Another important contribution of this study is to develop a generalized prediction model for the elastic moduli of both normal and high strength concrete. Numerous concrete compressive strength test results are obtained from the literature to develop the models. A comprehensive comparative study is conducted to verify the performance of the models. The proposed models perform superior to the existing traditional models, as well as those derived using other powerful soft computing tools.

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