Linear Static Analysis of Jack Up Structure at Different Modes of Operations

Abstract: A Jack up is an offshore structure with tubular members consisting of a buoyant hull which is self-elevating with number of movable legs, capable of raising its hull over the surface of sea. The Jack up is also called a mobile platform. The buoyant hull enables transportation of the unit and all attached machinery to a desired location. Once on location the hull is raised to the required elevation above the sea surface on its legs supported by the sea bed. The legs of such units may be designed to penetrate the sea bed, may be fitted with enlarged sections or footings, or may be attached to a bottom mat. It experiences various type of loading such as wind, wave and current forces. There are specific formulae for finding these loads in the structure. Different classification societies like API, ABS, and DNV etc. have certain rules for the construction of the Jack up. Some studies are done on these rules given by classification societies and a certain rule is selected for the present study. Loads will be calculated and the structure will be modeled using FEA package ANSYS 10.0. Finally results will be tabulated for different water depths.

Key words: Hull, Jack-Up, Offshore, Self-elevating, Wave.

Reference
[1] M.J. Cassidy, P.H. Taylor, R. Eatock Taylor, and G.T. Houlsby, Evaluation of long-term extreme response statistics of Jack-up platforms, Journal of Ocean Engineering,29, 2002, 1603-1631.
[2] A. Dier, M. Howarth, W. Jones, and R.J. Hunt, Jack-up response to wave-in-deck loads during extreme storms, Journal of Marine Structures, 17, 2004, 275-290.
[3] Bernt J. Leira & Daniel Karunakaran, Site-dependent Reliability of a Mobile Jack-up Platform, Journal of Marine Structures, 8, 1995, 151-169.
[4] R.W.P. Stonor, K. Nelson, and T. Versavel, Measurement of seabed fixity and dynamic behaviour of the Santa Fe Magellan jack-up, Journal of Marine Structures, 14, 2001, 451-483.
[5] C.P. Ellinas, Mechanics of Ship/Jack-up Collisions, Journal of Construct. Steel Research, 33, 1995, 283-305.

Numerical Analysis of Concrete at Elevated temperatures

Abstract: Generally, concrete structures works at room temperature and this temperature will not fluctuate. But building fire accidents causes the structure in a building bearing a high temperature attack to reach maximum temperatures or even higher within a short time. As concrete is a conducting material, it conducts this elevated temperature and due to conduction temperature develops within the structure. The paper includes the development of coding for finding temperature distributed within concrete structure when subjected to elevated temperatures. Coding for non-linear transient heat conduction analysis will be generated and also a case study will be conducted. The work will be conducted for 2D state of temperature distribution. MATLAB software is used for coding and analysis.

Key words: Coding, Elevated, implicit, Non-linear, Transient

Reference
[1] Guo and Shi, Experiment and Calculation of Reinforced Concrete at Elevated Temperatures, Tsinghua University Press Published by Elsevier Inc.,(2011).
[2] Lewis, Nithiarasu, seetharamu, Fundamentals of the Finite Element Method for Heat and Fluid Flow (Published by John Wiley & Sons, Inc., 2004).
[3] Incropera, DeWitt, Bergman, Lavine, Funda-mentals of Heat and Mass Transfer 6th Edition (Published by John Wiley & Sons, Inc)
[4] M. Asghar Bhatti, Fundamental Finite Element Analysis and Applications (Published by John Wiley & Sons, Inc., 2005).
[5] Bergheau, Finite Element Simulation of Heat Transfer (Published by John Wiley & Sons, Inc., 2004).

Finite Element Analysis of Mooring Cable

Abstract: The Mooring refers to the means for providing the connection between the structure and the seafloor. It is used for securing the structure against the environmental forces. Moorings typically have three basic components anchor, chain or cable and floating devices. The mooring system relies on the strength of the anchors, digging depth and the soil properties. The mooring lines run from the structures to the anchors on the seafloor these are made up of synthetic fiber rope, wire and chain or a combination of these. The catenary mooring system is the most commonly used system and at the seabed, the mooring cable lies horizontally. The rope comes in at 30- 45 degree angle with the seabed. The different forces are acting on the mooring cable under tidal and climatic conditions such as current force, wave force and wind force. In this analysis studied the behaviour of mooring cable attached to buoy and spar platform under environmental forces using FEA package ANSYS 10.0. The application of CFRP material as a mooring cable instead of existing steel and fibre rope mooring cables is studied.

Key words: Buoy, Offshore, Spar, Vessels, Wave.

Reference
[1] R.Natarajan and C.Ganapathy, 1995, Analysis of mooring of a berthed ship. Marine Structures. Vol.8, 481-499.
[2] S.A.Mavrakos et al, 1996, Deep water mooring dynamics. Marine Structures. Vol.9, PP. 181-209.
[3] Yungang Liu and Lars Bergdahl, 1998, Extreme mooring cable tensions due to wave-frequency excitations. Applied Ocean Research. Vol.20, PP. 237-249.
[4] D.T. Brown, S. Mavrakos, 1999, Comparative study on mooring line dynamic loading. Marine Structures. Vol.12, 131-151.
[5] M.A Vaz and M.H Patel, 2000, Three-dimentional behaviour of elastic marine cables in sheared currents, Applied Ocean Research, Vol.22, 45-53.

Linear Analysis of Guyed Mast Subjected to Wind, Ice and Seismic Loading

Abstract: Masts are, tall structures designed to support antennas for telecommunication, broadcasting and television. They are among the tallest man-made structures. The telecommunication guyed mast towers are the kind of towers which are not self-supporting and requires external support of guys to stand. In the present work structure has been modeled with two node space truss element. Equivalent static wind loads has been calculated as per IS 875-1987 (part3).This paper aims at investigating the, linear time history, structural non linearity of the structure subjected to the influence of wind, ice and earthquake loading. For the purpose of research activity, a 100m mast tower has been analyzed using SAP2000V14. Loads will be calculated and the structure will be modeled using SAP2000v14.

Key words: Guyed mast, linear analysis, wind load, ice load, natural frequencies.

Reference
[1.] C. Grantes and J. J. Connor, Modelling, Loading,and Preliminary Design Considerations for Tall Guyed Towers, Journal of computers and structures, engineering information technology and constructed facilities division, 49, 1993, 797-805.
[2.] Gregory M. Hen and Raymond H. Plaut, Three-dimensional analysis of the seismic response of guyed masts, Journal of engineering structures, 29, 2007, 2254-2261.
[3.] Shantaram G.Ekande and Murty K.S. Madugula, Geometric Non-linear Analysis of three dimensional guyed towers, Journal of computers and structures, 29, 1987, 801-806.
[4.] G.G. Amiri And G. McClure, Seismic response of tall guyed telecommunication towers, Eleventh World Conference on earthquake engineering, 1993, 1882.
[5.] Anders Ansell, The dynamic element method for analysis of frame and cable type structures, Journal of engineering structures, 27, 2005, 1906-1915.

Finite Element Analysis of Ribbed Dome

Abstract: Large spans have always fascinated people since unobstructed closed places have been demanded for many purposes. Dome structures are the most preferred type of large spanned structures. For understanding the behaviour of ribbed dome structure, in this paper ribbed spherical dome with rigid joints are considered. Three different spans of domes are considered for analysis. The proposed dome will be modeled and analysis to be done by using software's ANSYS and Staad.Pro for different rise to span ratios for different load cases and results are compared. Failure of dome is generally due to buckling of the structure. It is a sudden failure occurs to the structure when in reaches a critical load, which is the maximum load which a member can support before it becomes unstable. Failure of dome structure is due to buckling of members. In the present study buckling load of ribbed spherical dome is calculated using finite element software ANSYS. A Parametric study is also conducting buckling analysis by changing the rise to span ratio of the dome

Key words: Ribbed Dome, Member Buckling, Buckling Load

Reference
[1] Stephen P Timoshenko & S Woinowsky Krieger, "Theory of Plates and Shells", Second Edition, Mcgraw –Hill Publishing Company Limited,New Delhi,2010.
[2] Shiro Kato, Itaru Mutoh, Masaaki Shomura, Collapse of semi-rigidly jointed reticulated domes with initial geometric imperfections, Journal of Constructional Steel Research,48, 1998, 145–168.
[3] Ronaldo C. Battista, Miche`le S. Pfeil, Eduardo M. Batista, Strengthening A Reticulated Spherical Dome Against Local Instabilities, Journal of Constructional Steel Research,57, 2001, 15–28.
[4] Wenjiang Kang , Zhihua Chen , Heung-Fai Lam , Chenran Zuo, Analysis And Design Of The General And Outmost-Ring Stiffened Suspen-Dome Structures,Engineering Structures,25, 2003, 1685-1695.
[5] Shiro Katoa, Tetsuo Yamashitab, Shoji Nakazawaa, Yun-beom Kima, Atsushi Fujibayashia,Analysis Based Evaluation For Buckling Loads Of Two-Way Elliptic Paraboloidal Single Layer Lattice Domes,Journal of Constructional Steel Research,63, 2007, 1219–1227.

Effect of Mineral Admixtures on Durability Properties of High Performance Concrete

Abstract: Concrete is the most commonly used construction material. The premature deterioration of concrete structures in aggressive environments has led to the development of high performance concrete (HPC). The production of HPC involves appropriate selection and proportioning of the constituents to produce a composite mainly characterised by its low porosity and fine pore structure. These, in turn improve the resistance of concrete to the penetration of harmful substances such as chloride and sulphate ions, carbon dioxide, water and oxygen, and hence enhance durability performance. The improved pore structure of HPC is mainly achieved by the use of chemical and mineral admixtures. In the present study the effect of mineral admixtures on the durability properties of HPC is investigated. A control mix without any mineral admixtures having a compressive strength was designed of 60MPa and two other mixes are prepared one by replacing cement by 10% metakaoline and other by replacing cement with 10% metakaoline + 30% fly ash respectively The workability tests were carried out on the fresh mix. Durability properties were determined by conducting sulphate attack test, acid attack test and rapid chloride permeability test.

Key words: deterioration, high performance concrete, mineral admixtures

Reference
[1.] M.F.M. Zain, M. Safiuddin, K.M. Yusof ,A study on the properties of freshly mixed high performance concrete Cement and Concrete Research 29 , 1999, 1427–1432
[2.] Mohd Zain, M. F. and S. S. Radin ,Physical properties of high-performance concrete with admixtures exposed to a medium temperature range 20°C to 50°C, Cement and Concrete Research, 30, 2000, 1283-1287.
[3.] K.E. Hassan, J.G. Cabrera, R.S. Maliehe The effect of mineral admixtures on the properties of high-performance concrete Cement & Concrete Composites 22 ,2000, 267-271
[4.] M.F.M. Zain, Md. Safiuddin, H. Mahmud Development of high performance concrete using silica fume at relatively high water binder ratios Cement and Concrete Research , 30 , 2000, 1501-1505
[5.] C. S. Poon,L. Lam, S.C. Kou, Y.-L. Wong, Ron Wong Rate of pozzolanic reaction of metakaoline in high-performance cement pastes Cement and Concrete Research 31, 2001, 1301–1306

Modal Analysis of Shear wall with various Finite Elements and its Validation

Abstract: Shear walls are constructions meant to resist earthquakes to an extent Concrete and steel shear walls are being constructed in multi-storeyed buildings to lessen the effects (responses of the structure in terms of the motion parameters – displacement, velocity, etc.) in many parts of the world .Several examples of the Finite element modal analysis of shear walls is cited in the literature literature .But, many of them lie far away from predicting the experimental modal shapes of shear walls due to the limitations of the software and poor element shapes .Use of more refined mesh and higher order elements and some special treatments are suggested as possible solutions to bring the modal analysis close to the experimental results and some of the case studies. An attempt towards this direction using ANSYS software is the primary aim of this thesis. The objective of this thesis is to investigate the use of the finite element method for the analysis of reinforced concrete shear wall and evaluate the rate of convergence of elements

Key words: h-Refinement, L2 Error norm, Modal Analysis, Refined mesh, Shaking Table.

Reference
[1] Martinelli P and Filippou .C,(2009); Simulation of the shaking table test of a seven-story shear wall building, Earth quake engineering and structural dynamics, Vol 38:pp587–607.
[2] Kelly, T.E, December 2004, Nonlinear Analysis of Reinforced Concrete Shear Wall Structures", Bulletin of the New Zealand Society for Earthquake Engineering, Vol. 37, No. 4
[3] Kazaz, I. and Yakut, A., 2005, "Numerical simulation of dynamic shear wall tests:A benchmark study", Computers and Structures Vol 84 , pp 549-562
[4] Abidi, M., 2012, "Review on Shear Wall for Soft Story High-Rise Buildings" , International Journal of Engineering and Advanced Technology, Vol 1, Issue-6.
[5] Abdo, M., 2012, Modeling of Shear-wall Dominant Symmetrical Flat-plate Reinforced Concrete Buildings, "International Journal of Advanced Structural Engineering", Springer open journal

Prediction of Crack Propagation Using Finite Element Method

Abstract: Cracks occur in many structural parts due to various causes. Stress concentrations at the crack tips and crack propagation due to tensile stresses are active areas of research in the past many decades. Finite element analysis of prediction of crack growth has been cited in many the literature. Element distortions, breakage of elements, coarse mesh, lower order elements, material and geometric non-linearity etc are some of the issues faced in the analysis of cracks with finite elements. An attempt towards improving the prediction of crack propagation using finely refined mesh near the crack tip, higher order elements and better material models as available in the ANSYS software is the aim of this thesis. A rectangular plate with a crack originating due to impact loading and propagating towards one direction is taken as an example to illustrate this.

Key words: Crack opening displacement, Crack tip velocity, Fracture mechanics, Fracture toughness, Stress intensity factor

Reference
[1] A.R. Shahani, M.R. Amini Fasakhodi , Finite Element Analysis of Dynamic Crack Propagation Using Remeshing Technique, International Journal of Materials and Design, 2(30), 2009, 1032-1041.
[2] T Nishioka and S N Atluri, Numerical Analysis of Dynamic Crack Propagation: Generation and Prediction Studies, Journal of Engineering Fracture Mechanics, 16(3), 1982, 303-332.
[3] Dr. Fathi A. Alshamma and Ali Fahad Fahem, A Study of the effect of impact loading on DSIFs and crack propagation in plate, Research Journal of Recent Sciences, 2(2), 2009, 85-91.
[4] G. Weisbrod and D. Rittel, A method for dynamic fracture toughness determination using short beams, International Journal of fracture, 3(3), 2000, 89-103.
[5] Kishimoto, Fugino, Aoki, Sakata, The Influence of Dynamic effects in Impact Testing, International Journal of fracture, 13(4), 1977, 538-531.

Finite Element Analysis of Steel Storage Tank Under Siesmic Load

Abstract: The objective of this article is to study the effect of various components of earthquake on sloshing response of liquid storage tanks. First, commonly used theory for unidirectional analysis of liquid behavior in cylindrical tanks was reviewed. Second, the Finite Element Modeling (FEM) strategy which was used to simulate dynamic response of the liquid tank system was described. The FEM was validated using a set of manual calculation which is used in available design guidelines. Third, a parametric study for some vertical, cylindrical ground supported tanks with different aspect ratios excited by various time series of earthquake accelerations was performed. Each tank was subjected to unidirectional and bidirectional excitations of earthquakeaccelerations. Fourth, the variations of maximum sloshing wave height during the above analysis weredescribed. Fifth, thetanks under this study were analyzed in a known earth quake in India and the effects on sloshing wave height were studied. Finally, the available simplified formulation for evaluating MSWH under unidirectional excitation was extended for bidirectional excitation and a simple procedure is developed with the help of software

Reference
[1.] Simple Procedure for Seismic Analysis of Liquid-Storage Tanks by Praveen K. Malhotra, Thomas Wenk, and Martin Wieland., journal of Engineering Failure Analysis., (2010) 191–198
[2.] Heuristic optimization of cylindrical thin-walled steel tanks under seismic loads by Minas K. Minoglou and George D. Hatzigeorgiou., journal of Thin-Walled Structures., (2013) 50–59
[3.] Seismic response of base isolated liquid storage tanks by Ayman A. Seleemah and Mohamed El-Sharkawy., Ain Shams Engineering Journal., (2011) 33–42
[4.] Failure analysis and finite element simulation of deformation and fracture of an exploded CNG fuel tank by Majid Mirzaei and Mohammad Malekan., journal ofEngineering Failure Analysis., (2013) 91–98
[5.] Wu, G.X., Ma, Q.W., and Eatock-Taylor, R. (1998). "Numerical Simulation of Sloshing Waves in a 3D Tank Based on a Finite Element Method", Appl. Ocean Res 20, 337-355.

Experimental Investigation On The Strength Aspects Of Flyash Based Geopolymer Concrete

Abstract: Ordinary Portland Cement (OPC) becomes an important material in the production of concrete which act as itsbinder to bind all the aggregate together. However, the utilization of cement causes pollution to the environment andreduction of raw material (limestone). The manufacturing of OPC requires the burning of large quantities of fuel anddecomposition of limestone, resulting in significant emissions. As such, alternative materials had been introduced toreplace OPC in the concrete. Geopolymer concrete had been introduced to reduce this problem. This paper discussesabout the strength properties of fly ash based Geopolymer concrete. Fly ash based Geopolymer concrete offersseveral economic benefits over Portland cement concrete. The results obtained were far better than conventionalconcrete.

Key words: Geopymer Concrete,Flyash .

Reference
1.Joseph Davidovits and VijayaRangan.(2010), Geopolymer Cement and Concrete. International Workshop on Geopolymer cement and concrete, Annamalai University, Annamalainagar, Tamilnadu.
2. Hardjito D and Rangan. B.V (2005), Development and properties of low Calcium fly ash based geopolymer Concrete– Research report GC 1, Faculty of Engineering, Curtin University of Technology, Perth, Australia.

Finite Element Analysis of Buildings under Blast Loading

Abstract: This paper deals with the effect of low-energy pyrotechnic explosive loading on brick masonry structures and the influence of various structural members in resisting the collapse. Different openings and incorporation of lintel and plinth beam are dealt in this study. The static response of brick masonry in the event of accidental explosion is analysed using the model proposed by ANSYS 14.5 software. It was observed that, by providing additional structural elements, the resistance of brick masonry against accidental overloading can be improved considerably so that progressive collapse of the entire structure can be avoided. This paper concludes that an alternate construction material is to be considered for the construction of fireworks and matchworks industrial buildings, which can perform satisfactorily than conventional brick masonry.

Key words: ANSYS,Blast loading, Brick Masonry, Deflection, Finite Element Analysis

Reference
[1]. Chaf, Qualification and Control of the Hazards associated with the Transport and Bulk Storage of Fireworks, EC Contract Evg1-CT-2002-00074 (2002).
[2]. Salzano E, Basco A, Cammarota F. Confined After-Burning of Display Pyrotechnics and Explosives, Italian Selection of Combustion Institute, 2009, pages V3- 1 to 6.
[3]. Sekar. T, S.N. Ramaswamy and NVN. Nampoothiri, Studies on strengthening of brick masonry structures in fireworks industries against Accidental explosions, Asian Journal of Civil Engineering, Vol.13, No.6, December 2012, pages 743-752.
[4]. S.N. Ramaswamy and A.M. Arunmohan, Static and Dynamic Analysis of fireworks industrial buildings under impulsive loading, IJREAT International Journal of Research inEngineering & Advanced Technology, Volume 1, Issue 1, March 2013.
[5]. NFPA 1124: Code for the manufacture, transportation, storage, and retail sales of fireworks and pyrotechnic articles, National Fire Protection Association, USA.

Strength Characteristics of Structural Concrete Elements Using Foundry Sand

Abstract: The over exploitation of non-renewable materials is becoming a threat and therefore it is necessary to seek the possibility of recycling them, once their durability is expired. The recycled materials can be used effectively in architectural and civil engineering fields. They can stand close to the concept of green concrete which is in compatible with the environment. Foundry sand from casting industries is a waste material which is dumped extensively and in this study an attempt has been made to evaluate the usage of this waste material in concrete. The constant depletion of sand beds at all major sources of availability is a major concern and thus efforts are taken in order to replace sand in construction activities. In this study, effect of foundry sand as fine aggregate replacement on the compressive strength, flexural strength and split tensile strength of concrete with a mix proportion of 1: 1.28: 2.56: 0.45 was investigated at different limited curing periods (7 days and 28 days). The percentage of foundry sand used for replacement were 10%, 20%, 30%, 40%, 50%, 75% and 100% by weight of fine aggregate. Test showed impressive results, showing capability of foundry sand for being a component in concrete for imparting strength. Making concrete from recycled materials saves energy and conserves resources which lead to a safe sustainable environment.

Key words: Casting industry, Foundry sand, Landfill, Recycling, Sustainable environment

Reference
[1] Reddi, Lakshmi, Rieck, P. George, Schwab, Chou and Fan, Stabilization of Phenolics in Foundry Sand Using Cementious Materials, Journals of Hazardous Materials, 45, 1995, 89-106.
[2] T R Naik and S S Singh, Permeability of Flowable Slurry Materials Containing Foundry Sand and Fly Ash, Journal Of Geotechnical and Geoenvironmental Engineering-ASCE, 123(5), 1997, 446-452.
[3] Tikalsky, J. Paul, Smith, Earl, Regan and W. Raymond, Proportioning Spent Casting Sand in Controlled Low-Strength Materials, ACI Material Journal, 95(6), 1998, 740-746.
[4] Tikalsky, J. Paul, Smith, Earl, Regan and W. Raymond, Properties of Controlled Low Strength Materials Containing Foundry Sand, ACI Material Journal, 97, 2000, 698-702.
[5] T R Naik, and S S Singh, Performance and Leaching Assesment of Flowable Slurry, Journal of Environmental Engineering, 127(4), 2001, 359 – 368.

A Comparative Study on the Strength of Structural Elements by Incorporating Waste Latex Paint in Concrete

Abstract: Reuse and recycling keep materials out of waste disposal cycle for long time while preserving natural resources. Waste Latex paint (WLP) contributes significantly towards liquid waste and its disposal has become a major concern for environment. This project focuses on sustainable development through the recycling of waste latex paint by incorporating in concrete. It also aims at determination and comparison of strength characteristics of normal structural concrete and by incorporating different percentage of WLP by partially replacing required water content. From the laboratory test results it has found that introduction of waste latex paint can improve some key properties of concrete such as workability, durability, flexural strength etc.

Key words: Concrete, Recycling, Waste Latex Paint, Water content

Reference
[1] Nehdi, M., and Summer, J.―Recycling Waste Latex Paint in Concrete‖, Cement and Concrete
Research,33(6),2003,857-863. [2] Ohama, Y., ―Principle of Latex Modification and Some Typical properties of Latex Modified Mortars and Concrete,‖ ACI Materials Journal, 84(6),1987,511-518.
[3] Jiong Hua, Kejin Wangb, James A. Gauntb.,―Recycling lead-based paint contaminated deconstructed masonry materials as aggregate for Portland cement concrete—A cost effective and environmental friendly approach‖, Conservation and Recycling
Journal,54,2010,,1453–1460. [4] Nehdi, M, ―Recycled Waste Latex Paint as an Admixture in Concrete Sidewalks‖, (March 2004), Cement and Concrete Research ,219, 131-144.
[5] Almesfer, N., Ingham, J., ―Effect of waste latex paint on concrete‖, Cement & Concrete Composites, 2013,223 - 242.

Strength Studies on Silica fume Based Cement Mortar

Abstract: Silicafume is considered to be the most suitable cementitous material for increasing the strength of mortars. An optimum percentage of cement has to be replaced with silicafume without affecting the workability. This optimum percentage of replacement and optimum water content for the mix has to be fixed by conducting experimental studies. This study deals with the hardened properties of silica fume based cement mortar. Compressive strength,flexural strength and durability of cement mortar modified with silicafume was determined in this study.

Key words: Microstructure, Pozzolonic reaction, Smelting.

Reference
[1] Appa Rao.G Role of water-binder ratio on the strength development in mortars incorporated with silica fume ,Cement and Concrete Research 31 , 2001 443-447
[2] IS 1727 -1967 Indian Standard methods of test for pozzolanic materials
[3] ASTM C 1202 – 97, Standard Test Method for Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration
[4] ASTM C 348 – 9702, Standard Test Method for Flexural Strength of Hydraulic Cement Mortars
[5] Feldman.R.F and Cheng yi.H Resistance of mortars containing silica fume to attack by a solution containing chlorides, cement and concrete research 15, 1985 , 411–420

Early Age Properties Of Silica Fume Modified Cement Mortar With M Sand As Fine Aggregate

Abstract: This paper emphasizes on the influence of silica fume on the early age properties of cement mortars incorporated with silica fume as cement replacement material. Silica fume was varied at different percentages. The water-binder ratio was fixed according to the workability of each mix. The workability and density of conventional mortar, consistency and setting times of cement pastes with varying percentages of silica fume were studied. The experimental results showed that, the water demand was increasing with increasing replacement level of silica fume. The consistency of cement was increased with increase in silica fume content.The initial setting time was decreasing with the increase in silica fume content and the final setting time seems to be not influenced by the silica fume.The density increased up to 10% of replacement level and it was decreased with increasing percentages of silica fume.

Key words: Consistency,Mortar,Setting time,Silica fume,Workability

Reference
[1] Al-Sugair, F. H (1995) Analysis of the Time Dependant Volume Reduction of Concrete containing Silica Fume, Magazine of Concrete Research,47, 77-81.
[2] Goldman, A. and A.Benture (1989) Bond Effects in High Strength Silica Fume Concrete, ACI Material Journal, 86, 440-447.
[3] Poon, C. S., L. Iam and Y.I.Wong (1999) Effects of Fly-Ash and Silica Fume Interfacial Porosity of Concrete Journal of Materials in Civil Engineering, 3, 197-204.
[4] Sahar,E.S.Z.F (1989)Short and Long-Term Properties of Silica Fume High Strength Mortar,M.S. Thesis, Zagazig University.
[5] Sellevold, E. J (1987) The Function of Condensed Silica Fume in High Strength ConcreteProceedings, Symposium on Utilization of High Strength Concrete, Tapir Publishers, Trondheim, 39-49.

Experimental investigation on the shear strength of concrete beams longitudinally reinforced with GFRP bars

Abstract: The model originally proposed by IS: 456(2000) for the prediction of shear strength of concrete beams longitudinally reinforced with steel bars depends on the longitudinal reinforcement ratio and is independent of the characteristics of longitudinal bars used in concrete beams. Hence in this paper, an attempt has been made to investigate the efficacy of using IS: 456(2000) to predict the shear strength of concrete beams longitudinally reinforced with GFRP bars. In this study, eight concrete beams longitudinally reinforced with GFRP bars without stirrups were cast and tested over shear span to depth ratio between 0.5 and 1.75. The variables of experimental program are shear span to depth (a/d) ratio, longitudinal reinforcement ratio (p(sub>t) and cross section of the beam. The experimental shear strength observed for these eight test beams are compared with the corresponding predicted shear strength using the model given in IS: 456(2000). The mean of experimental shear strength to the predicted shear strength based on IS: 456(2000) is found to be 1.18 with a standard deviation of 0.09 and reveals the better fit of the model by IS: 456(2000) to predict the shear strength of concrete beams reinforced with GFRP bars.

Key words: beam, concrete, GFRP, prediction, shear strength

Reference
[1] L.C.Bank, Composites for Construction: Structural Design with FRP Materials,(NJ:John Wiley & Sons Inc., 2006).
[2] Recommendations for design and construction of concrete structures using continuous fibre reinforced materials, JSCE: 1997, Japan Society of Civil Engineers, Tokyo, Japan
[3] Interim guidance on the design of reinforced concrete structures using fibre composite reinforcement, BISE: 1999, British Institution of Structural Engineers, London.
[4] Guide for the design and construction of concrete structures reinforced with fiber-reinforced polymer bars, CNR-DT-203-NRC-06:2006, National Research Council, Rome.
[5] Guide for the Design and Construction of Structural Concrete Reinforced with FRP bars, ACI 440.1R-06, ACI Committee 440: 2006, American Concrete Institute, Michigan

Development of Excel Sheets for the Design of Columns Under Tension or Compression, Biaxial Bending, Shear in Both Directions and Torsion

Abstract: Many analytical softwares do not support design of columns subjected to tension or compression, biaxial bending, shear in both directions and torsion. Tension in columns occurs especially in columns of buildings subjected to horizontal loads due to wind or earthquake forces. Hence, a simple method is developed using MS excel sheet, from the existing Indian codal procedures. Results are compared with existing literature and comparison graphs show that results are matching with the existing literature. Hence, these excel sheets can be used in conjunction with the analytical softwares like STAAD and ETABS for the design of columns. Importance of this procedure lies in the fact that modification or alteratation can be made at any step and can be used for a vast number of columns in a short time during the design of mult-istoried buildings.

Key words: Analytical softwares, Biaxial bending, columns,shear in both directions and torsion.

Reference
[1] Park and Paule, Reinforced concrete structures( NJ: Prentice-Hall, 1969).
[2] IS 456-2000, Indian standard code of practice for plain and reinforced concrete – code of practice (Bureau of Indian Standards, New Delhi,2000).
[3] SP 16-1980,Design aids for reinforced concrete to IS 456-1978 (Bureau of Indian Standards, New Delhi, 1980).
[4] BS 8110- Part 1, 1985,Structural use of concrete, Part 1 code of practice for design and construction (British standards institution, London).
[5] Punmia. B.C., Limit state design of reinforced concrete (Laxmi Publications Pvt. Limited, New Delhi, first edition 2007, reprint 2011).

Experimental Investigation Of Self Compacting Concrete With Copper Slag

Abstract: The concrete technology has made tremendous strides in past decade. Concrete is now no longer a material consisting of cement, aggregates, water and admixtures but it is an engineered material with several new constituents. The concrete today can take care of any specific requirements under most of different exposure conditions. The concrete today is tailor made for specific applications and it contains several different materials like PFA, GGBSF, Micro silica, Metakaolin, Colloidal Silica and several other Binder, Filler and Pozzolanic materials. The development of specifying the concretes as per its performance requirements rather than the constituents and ingredients in concrete has opened innumerable opportunities for producer and user of concrete to design concrete as per specific requirements. In that way self compacting concrete has been developed in Japan in 1990‟s. In this project literature review of SCC has been done and the mix design has been arrived as per EFNARC Specifications. For the developed mix design, the self compactability has been checked. At first the normal concrete is prepared and then further steps 5% - 25% of sand is partially replaced as copper slag, self compact ability test such as slump flow, V- funnel and J-ring tests have conducted and their results are reported. Also compressive, Split- Tensile strength and have been conducted and the results are compared. To know the optimum dosage of super plasticizer for each mix combination of cement, Fly ash, SF and Marsh cone test has been conducted and their results are reported.

Reference
[1.] Kato, K. Yang, S.H. and Kunishima, M. (1993) "A Comparative Study of the Constructability of SCC", Concrete 2000, pp 881-889.
[2.] Okamura, H., and Ozawa,K. (1994), " Self Compactable HPC in Japan", SP169, ACI, Deitrot,pp31-44.
[3.] Sakata,K., Ayao, T. and Ogawa, A., (1995) " Mixture Proportioning for Highly Flowable Concrete Incorporating Limestone Powder", ACI, Sp 153-14,pp 249-268.