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The Effect of Steel Fiber on Some Mechanical Properties of Self Compacting Concrete
Issue:
Volume 1, Issue 3, November 2013
Pages:
102-110
Received:
4 October 2013
Published:
10 November 2013
Abstract: Self compacting concrete (SCC) is compacting itself alone due to its self-weight and is filled almost completely while flowing in the formwork. In structural members with high percentage of reinforcement ,it fills also completely all voids and gaps. The purpose of presented research is to investigate, the fresh properties of Steel Fiber SCC and the hardened properties. Fresh properties comprising flow ability, passing ability, and viscosity related segregation resistance. Hardened properties comprising compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, and Ultrasonic pulse velocity. The results indicated of the fresh properties of SCC with steel fiber , reduction in workability with increase of steel fiber content. Also the Steel fibers had effect on compressive & tensile strength , modulus of elasticity and ultrasonic pulse velocity of steel fiber self compacting concrete, there was an optimum content of steel fiber at which higher performance obtained at the both mentioned characteristics ,the content was(0.75- 1)% . All fiber mixes demonstrated higher splitting tensile strength, and flexural strength relative to plain mix at all curing ages. The strengths increased as the fiber content increased. The fibers slightly decrease the U.P.V followed the same behavior as in compressive strength of SCC.
Abstract: Self compacting concrete (SCC) is compacting itself alone due to its self-weight and is filled almost completely while flowing in the formwork. In structural members with high percentage of reinforcement ,it fills also completely all voids and gaps. The purpose of presented research is to investigate, the fresh properties of Steel Fiber SCC and the...
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Evaluation of Torsional Capacity of Square RC Columns Strengthened with CFRP Using Finite Element Modeling
Ahmed Sameer Younus,
Ammar A. Abdul Rahman
Issue:
Volume 1, Issue 3, November 2013
Pages:
111-123
Received:
7 October 2013
Published:
10 November 2013
Abstract: Researches on behavior of reinforced concrete (RC) columns subjected to torsion including mechanical properties like cracks and failure modes are not commonly studied and investigated well. It is necessary to investigate the mechanical properties and characteristics for RC columns subjected to torsion during different types of loading including earthquakes. Also, as a reinforcing method to existing RC structures, the application of Carbon Fiber Reinforced Polymers (CFRP) became common. CFRP has properties of high tensile strength, light weight and easy execution. CFRP is easy to adjust the reinforcement volume whenever necessary and considered excellent in endurance because the rust will not occur. The purpose of this study is to present a model suitable for analyzing square RC columns strengthened with CFRP under torsional effects and developing a reasonable method for calculating angles of twist for square concrete columns using the finite element method. Final available version of finite element analysis software [ANSYS 14 – 64 bits] is used to solve the problem and to predict the torsional behavior of the columns under investigation. The results are compared and verified with an experimental study and the numerical results showed acceptable agreement with the experimental results. Several important parameters affecting the torsional capacity of square columns strengthened with CFRP under torsion are studied in parametric study. These parameters include: the presence (distribution type) of CFRP, CFRP number of layers (thickness), type of interface between CFRP layers and concrete surface, CFRP orientation and effect of applying axial load in addition to torque. The results showed that zebra shape (where sheets are straight and fibers are inclined with 45o) is the best way to increase the torsional capacity of RC columns.
Abstract: Researches on behavior of reinforced concrete (RC) columns subjected to torsion including mechanical properties like cracks and failure modes are not commonly studied and investigated well. It is necessary to investigate the mechanical properties and characteristics for RC columns subjected to torsion during different types of loading including ear...
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An Experimental Study of Longitudinal Velocity Distribution at Cross-over and Bend Section of a Compound Meandering Channel
Md. S. M. Khan,
Md. Abdullah Al Amin,
Md. Mafizur Rahman,
Sarder Rafee Musabbir,
K. M. Julfikar Tareq
Issue:
Volume 1, Issue 3, November 2013
Pages:
124-128
Received:
25 October 2013
Published:
20 November 2013
Abstract: Generally, river flow can be schematized as compound meandering channel in which the longitudinal velocity distributions in the crossover and bend section are completely different and quite intricate. Engineers, Planners and Researchers are highly interested in predicting accurately as well as estimating quantitatively and reliably the longitudinal velocity distribution in a compound meandering channel. A laboratory experiment has been conducted in a compound meandering channel with symmetric cross-sections having floodplain width ratios (B/b) of 1.00, 1.67, 2.33, 3.00 and depth ratios (H-h)/h of 0.20, 0.30, 0.35, 0.40 using the large-scale open air facility in the Department of Water Resources Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka. Point velocity data have been collected using an ADV (Acoustic Doppler Velocity Meter) for different depth and width ratio at five different locations of a compound meandering channel. The traditional power law represents a vertical distribution of longitudinal velocity in open channel with maximum value at free surface and with zero at the channel bed. But the velocity distribution in the type of natural or laboratory compound meandering channel does not follow such velocity distribution. The longitudinal velocity distribution of a compound meandering channel shows two characteristics for all cases and depth ratios. In the bend section, velocity increases in the inner bend (convex) and decreases in the outer bend (concave). Similar nature is observed in the floodplain boundary for all cases and depth ratios. In the crossover of a compound meandering channel, velocity increases towards the mid-section and decreases in the boundary of the channel.
Abstract: Generally, river flow can be schematized as compound meandering channel in which the longitudinal velocity distributions in the crossover and bend section are completely different and quite intricate. Engineers, Planners and Researchers are highly interested in predicting accurately as well as estimating quantitatively and reliably the longitudinal...
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Evaluation Conduct of Deep Foundations Using 3D Finite Element approach
Issue:
Volume 1, Issue 3, November 2013
Pages:
129-134
Received:
6 December 2013
Published:
20 December 2013
Abstract: In most practical situations, the pile either include circular or rectangular cross-section. The pile with circular cross-sectional shape usually analyzed in previous studies and little for the second type. While, no studies included comparison between those common types to understand and recommend which is batter for case of deep foundations. Therefore, this study is mainly deal with the vertical pile response under vertical load (i.e. no horizontal loads) when take into account the shape factor. To achieve the objective of this research, 3D finite element approach has been used to simulate the whole deep foundation case study. This study includes many factors, such as pile depth that measured below ground surface, soil strength parameter and soil types. It can be seems that little influence of shape factor on the vertical performance of deep foundation. Therefore, it can be recommended that if no any source of lateral load, it can be used any type and it is depending only on cost of pile types.
Abstract: In most practical situations, the pile either include circular or rectangular cross-section. The pile with circular cross-sectional shape usually analyzed in previous studies and little for the second type. While, no studies included comparison between those common types to understand and recommend which is batter for case of deep foundations. Ther...
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