Vol 2 Issue 1 April 2014-September 2014

Abstract: This research presents a study on the seismic assessment of steel frames with Rotational Friction Dampers (RFDs). The devices were used to protect structures from damage during earthquakes. In this study, steel moment frames equipped with RFDs is investigated under Nonlinear Time History (NTH) and Incremental Dynamic Analysis (IDA). Maximum interstory drift ratio is studied as Engineering Demand Parameter (EDP). According to the IDA curves, it is concluded that by adding RFDs, the behavior of steel frames changes from hardening phase to severe hardening phase.

Keywords: Rotational friction damper, incremental dynamic analysis, IDA curve, maximum interstory drift ratio, engineering demand parameter.

Title: Incremental Dynamic Analysis of Steel Frames Equipped With Rotational Friction Dampers

Author: Mohammad Amin Montazer, Amir Shirkhani,Mohammad Hassan Mirabi Moghaddam, Saeed Rahmani

International Journal of Civil and Structural Engineering Research

ISSN 2348-7607 (Online)

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Abstract: Ultra high performance concrete (UHPC), even though a construction material with excellent performance is deemed to be unsustainable as per many opinions owing to its high cement content which raises the cost and pollution. This paper looks into the possibility of development of UHPC with high amount of cement replacement (around 70%) by two supplementary cementitous materials, slag and silica fume. The combination has been found to raise the early strength and late strength by approximately 10% and 17%   compared to a control mix as opposed to low early strength development when only slag is used and lower late strength ( than the blended mix) when only silica fume is incorporated. The scope of this paper also covers the effect of curing method on strength development of the proposed UHPC mix and concludes that choice of curing medium and method highly influence strength development. It also addresses the optimal fineness combination of slag and silica fume which contributes highest strength. The promising point is that for a fixed water-binder ratio, even with such low cement content, concrete can show appreciable strength improvement when blended with two admixtures given that proper curing method and fineness of admixtures are properly chosen. 

Keyword: Ultrahigh performance concrete, Silica fume, GGBS, Mineral admixtures, Fineness.

Title: Development Of Ultra High Performance Concrete Incorporating Blend Of Slag And Silica Fume As Cement Replacement

Author: Souradeep Gupta

International Journal of Civil and Structural Engineering Research

ISSN 2348-7607 (Online)

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Abstract: Both experimental and analytical investigation using ANSYS program have been performed on 2500 mm long with 0.8 mm thick steel core. These cores were placed with #8 diameter rods of Fe 415 as reinforcement and filled with M₂₀ grade self compacting concrete. Concrete Filled Steel Fluted Columns (CFSFT) with and without longitudinal reinforcement. Behaviour of concrete filled steel fluted columns having triangular flutes have been investigated by conducting experiment on thirteen columns. The parameters that have been chosen for the study are L/D ratios of 15, 20 and 25 and the number of reinforcements 3, 4, 5 and 6 of #8. The columns were placed on smooth plates at both ends and the columns were axially loaded and have been analysed for its stiffness and strength which have been presented. The percentage increase in strength from ANSYS specimens were 6.25%, 6.02% and 12.59% respectively. Axial deformation obtained from experiments in stiffness for L/D ratios of 15, 20 and 25 70.61%, 62.69% and 63.18% increased as compared to ANSYS.

Keywords: CFST, CFSFC, SCC, Triangular Flutes, Stiffness, Strength.

Title: Comparison of Experimental values with Analytical Evaluation of Concrete Filled Steel Triangular Fluted Columns for Concentric Load

Author: Dr.B.R Niranjan,  Eramma.H

International Journal of Civil and Structural Engineering Research

ISSN 2348-7607 (Online)

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Abstract: To build attentiveness about slenderness effect of column, this study is done with 15 flat-plate Reinforced Cement Concrete (RCC) structural models. Among these 15 models 45 columns of three locations (i.e. corner, edge and inner columns) are identified for study. First the methods describe in the ACI code for designing slender column is reviewed and then Finite Element Method (FEM) models are developed using ETABS. Parametric study is performed by considering: five different length of column from range of 10′(3048 mm) to 20′(6096 mm) using an increment of 2.5′(762 mm) and three slab panelsof size 15′x15′ (4572 mm x 4572 mm), 20′x20′ (6096 mm x 6096 mm), and 25′x25′(7620 mm x 7620 mm) with three panels in both way, with both gravity and environmental loads. It is observed that, columns in flat-plate structures are very sensitive to become slender. Corner and edge column has most slenderness effect. Column height increase on and beyond 17.5' (5334 mm) is substantially vulnerable for sway effect. Steel ratio increases suddenly when column length increases from one particular stage to another or column section decreases a little.In many cases, a column is not slender by considering now-sway frame but very slender by considering sway frame. For this reason, a designer should check a column for both non-sway sway conditions. Finally, ACI code for column design guidelines seems satisfactory with some outliers in column slenderness evaluation for flat-plat structures.

Keywords: Finite Element Method, Slenderness, Sway, Non-sway, Flat-plate.

Title: FEM Approach to Perform Parametric Study on Slender Columns for Flat-Plate Structures

Author: Mohammad Hossain, Tahsin Hossain

International Journal of Civil and Structural Engineering Research

ISSN 2348-7607 (Online)

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Abstract: The properties of UHPFRC mainly depend on the selection of ingredients with special curing and pre-compression techniques. In this project report, various proportions of materials, curing regimes and materials adopted by many researchers are discussed with special emphasis to the selection of materials as this forms the basis for proportioning of UHPFRC mixtures. The significance of this concrete is that the compressive and flexural strength is 5-10 times greater than the conventional concrete which is an indication of the improved performance of cement matrix interface achieved by various authors.   In India very few works have been reported in this field and mass application of these special concretes to practice can be brought about only after rigorous R and D works. Studies were already been done by Advanced Materials Laboratory, CSIR-Structural Engineering Centre(CSIR-SERC), Chennai, to develop various UHPFRC mixture proportions by using indigenously available materials and study the properties of these concretes for their application in practice. Currently Concrete with grade 200MPa has already been developed. In this research work the focus has been given to replace the sand with copper slag in the UHPFRC mix. Other ingredients include cement, silica fume, quartz powder, and micro steel fibers.

Keywords: Strengthening of concrete, M60grade, Density, Slump loss, Compressive strength, Split tensile strength, Flexural strength, CM – Control mixture, CWM – Concrete with waste materials, WM – Waste Material.

Title: STRENGTHENING OF ULTRA HIGH PERFORMANCE FIBER REINFORED CONCRETE USING WASTE MATERIALS

Author: G. ASOTHA, Prof. C. MALA

International Journal of Civil and Structural Engineering Research

ISSN 2348-7607 (Online)

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Abstract: Reinforced Concrete structures are suffering from various deteriorations like corrosion, cracks, spalling and large deflection. These deteriorations are caused by various factors such as aging, corrosion of steel reinforcement, environmental effects and accidental impacts on the structure. There are several options available for retrofitting the structural members of the existing reinforced concrete structures. Bonding of thin steel plates is the common method of retrofitting. Nowadays, bonding using fiber reinforced polymer sheets on to the damaged members helps to increase load carrying capacity, ductility and stiffness of the damaged structure. Such technique is an effective way to improve the flexural and shear performance of the reinforced concrete damaged structure. This project mainly focused on retrofitting the corrosion damaged reinforced concrete beams using mechanically fastened carbon fiber reinforced laminates. This type of retrofitting increases the load carrying capacity of the corrosion damaged reinforced concrete beams. It also increases the flexural and fatigue strength of the damaged reinforced concrete beam. Here, the general review of literature on the reinforced concrete structures, in which FRP used for strengthening purpose, is briefly presented and they were listed in the references at the end of the report.

Keywords: Rectification of damaged RC beams, Flexural strength, Load carrying capacity, Mechanical fastening of CFRP laminates. CB – Control beam, FWB – Fibre wrapped beam, FWB-MF – Fibre wrapped mechanically fastened beam.

Title: Strengthening Of Corrosion Damaged RC Beams Using Mechanically Fastened CFRP Composites

Author: S.UDHAYA MOORTHI, S.MADIVANAN

International Journal of Civil and Structural Engineering Research

ISSN 2348-7607 (Online)

Research Publish Journals