ICDCSE 2016- International Conference on Developments in Civil and Structural Engineering

"ICDCSE 2016 Conference Papers "

An Experimental Study on Mechanical Proper-ties of Self Curing Concrete[ ]


Today concrete is the most widely used construction material due to its good compressive strength and durability. The use of self-curing admixtures is very important from the point of view that saving of water is a necessity everyday (for each cubic meter of concrete requires 3m3 of water in a construction, most of which is used for curing). The aim of this investigation is to study the mechanical and durability properties of concrete using water-soluble Poly ethylene glycol (PEG-400) as self-curing agent. In this study, the mechanical properties of concrete containing self-curing agent is investigated and compared with those of conventionally cured concrete. The dosage of self curing agent is varying from 0.5% - 2.0% by weight of cement. Experimental results show that the self-curing gives better results as compared to conventionally cured concrete. The optimum dosage of PEG-400 for maximum strengths was found to be 1%.

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Evaluation of Mechanical Properties of Engineered Cementitious Composites[ ]


This paper investigates the mechanical properties of M40 grade Engineered Cementitious Composite (ECC) with recron and multifilament polypropylene fibre and durability property of conventional concrete and ECC. The values of compressive strength, split tensile strength, flexural strength and modulus of elasticity were measured. M40 grade ECC has higher compressive strength, tensile strength, flexural strength and modulus of elasticity as compared with M40 grade conventional concrete. The replacement of recronfibre by polypropylene fibre reduced the strength of ECC. This paper also presented the comparison of microstructure of conventional concrete and ECC.

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Experimental Investigation on Properties of Geopolimer Concrete Paver Block with the Inclusion of Polypropylene Fibers[ ]


This paper presents results of an experimental program to determine mechanical properties of Polypropylene Fibre Reinforced Geopolymer Concrete (PFRGPC) pavers which contains fly ash, alkaline liquids, fine & course aggregates & polypropylene fibers. Alkaline liquids to fly ash ratio were fixed as 0.35 with 100% replacement of ordinary Portland cement (OPC) by fly ash. Alkaline liquid consists of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) solutions. The ratio of Sodium hydroxide solution to Sodium silicate solution was fixed to 2.50. Polypropylene fibers Recrone 3S were added to the mix in volume of concrete. In this paper represent the results of the geopolymer paver block with the mix proportion of M 40 grade and polypropylene fibre with the different percentage rate. Test results indicate that by the addition of PPF by 0.2% it gives good results for abrasion resistance and flexural strength at 28 days respectively. Based on the test results, it was observed that the PFRGPC have relatively higher strength than GPC & OPC pavers.

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Effect of Lightweight Aggregate on the Flexural Behaviour of Self Compacting Concrete[ ]


Self-Compacting Concrete (SCC) is a flowing concrete mixture that is able to consolidate under its own weight. Density of all types of concrete depends on the coarse aggregate present in it. Concerns about the depletion of Natural Coarse Aggregate (NCA) and increase in self-weight of building with height, have led to the adoption of several alternatives, like lightweight Coarse aggregates (LCA). In this research work, a study was conducted to replace NCA by fly ash based LCA in SCC based on target compressive strength. An experimental investigation on flexural behaviour of SCC specimens having M50 grade for different percentage (25, 50, 75 and 100%) variation of NCA using LCA was carried out. The results were then compared with the control specimens (SCC containing NCA only).

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Flexural and Shear Behaviour of RC Beams Using SCC by Partial Replacement of Fine Aggregate with Granite Fines[ ]


Global consumption of natural river sand is very high due to the extensive use of concrete. The non-availability of sufficient quantity of ordinary river sand for making concrete structures is affecting the growth of construction industry in many parts of the country. The present work is aimed at developing a concrete using the granite scrap an industrial waste, as a partial replacement for fine aggregate in self-compacting concrete. The percentage of granite fines addition by weight of fine aggregate is in the increment of 5%. The workability tests and hardened concrete tests has been conducted to determine the optimum percentage replacement of fine aggregate (M Sand) with granite fines in SCC. The optimum percentage replacement of fine aggregate by granite fines in SCC was found to be 15%. Behaviour of RC beams was also studied. From the various observations, it can be concluded that granite fines (GF) can be used for the production of structural SCC

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EFFECT OF GLASS FIBER ON ALCCOFINE MIX CONCRETE[ ]


As a construction material, concrete is the largest production of all other materials. Concrete is a composite material composed of aggregate bonded together with fluid cement which hardens overtime. Efforts for improving the performance of concrete over the past few years suggest that cement replacement materials can be utilized to produce high strength concrete. The aim of this experimental study is to evaluate the performance of concrete containing supplementary materials such as alccofine and glass fiber. Glass fibers are added to concrete to impart energy absorption, toughness and impact resistant property and these in turn improve the fracture and fatigue property of concrete. An optimum of alccofine was determined experimentally. Later fibers were added in three percentages and the variations in the result were found out. Result indicated that with the increase in glass fiber content, there was an increase in compressive strength, split tensile strength and flexural strength.

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Optimisation of RC Bracing Configuration on Seismic Evaluation of RC Framed Buildings[ ]


A structure situated in high seismic area will have to withstand lateral load along with the gravity load. This may result in the development of high stress which leads to the severe damage of the structure. Shear wall, bracings are the most common type of lateral load resisting systems. The types of bracing, location of bracing have significant effects to the lateral capacity of the structure. This paper present an elastic seismic response of reinforced concrete frames with reinforced concrete braces in X braced pattern which are analyzed numerically for eleven storey building with 5-bay structures. The responses of braced frames of different patterns (bay, level and combinations thereof) have been compared with unbraced i.e. bare frame. Results such as time period, top storey displacement and inter storey drift have been compared.

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Sloshing Behaviour of Water in Water Tanks and Swimming Pools Subjected to Earthquake[ ]


Most swimming pools in multi-storeyed buildings are constructed without considering the consequences that might occur during the event of an earthquake. The sloshing and overtopping of the large volume of water can lead to additional damages. The objective of this study is to model a swimming pool and the sloshing movement of the water retained in it using ANSYS 16. The swimming pool will be modelled as a rectangular flat bottom constant depth concrete water tank. A comparison between the stresses developed when water is modelled as a static body and the stresses developed when sloshing is permitted is also carried out. The effect of variation in positioning the pool at various storeys of the building on the magnitude of stresses developed is also studied.

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PREDICTION OF MAXIMUM CRACK WIDTH FORMULA FOR RCC FLEXURAL MEMBER[ ]


A formula for the maximum crack width has been developed by incorporating eight governing parameters such as steel stress, grade of concrete, area of steel reinforcement, diameter of bars, % of steel reinforcement, spacing of bars, yield stress of steel reinforcement and concrete cover based on statistical analysis of the author’s test results reported in literatures using Statistical Package for Social Science (SPSS) software. An experimental investigation was also carried out on six RC beam models and compared with formula suggested in international codes such as BS 8110-1997/ IS 456-2000, ACI code 318, GBJ 10-89 1989, BS EN 1992-1-1: 2004 and ECP 203-2007. The performance of the proposed formula is checked with experimental results and it shows well correlation.

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Evaluation of Stress Block Parameters for SCC with Recycled Concrete Aggregate[ ]


The objective is to find the equivalent stress block parameters namely, the effective average concrete ratio and the stress block depth factor for Self Compacting Concrete(SCC)with recycled aggregate (RSCC). An experimental investigation is carried out on the stress strain characteristics of SCC by partially replacing 25, 50, 75 and 100 % of coarse aggregate by recycled concrete aggregate for varying design strength 30, 40, 50 MPa under monotonically increasing axial loading. A total of 45 cylinders are prepared to develop a stress strain model for RSCC. The results arethen compared with the existing models used for SCC and the Saenz model was found applicable for finding the stress block parameters. The proposed parameters were found to be lesser than the values for normal concrete specified by IS 456 and that these parameters could be used to determine the flexural strength of members mentioned above.

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Flexural Behavior of Concrete with Partial Replacement of Cement with Marble Powder and Fine Aggregate with Copper Slag[ ]


To protect the depleting natural sand source and limit the use of cement it is essential to find an alternative solution for the preparation of concrete. Sustainability can be achieved only by using suitable techniques of substitution and waste management. Marble powder and copper slag are such materials which are the byproducts of manufacturing industries. These can be used either as a filler material in cement or fine aggregate. This work focuses on replacement of cement with marble powder and fine aggregate with copper slag in M30 grade concrete. Here marble powder is added at an increasing percentage of 5% by weight of cement and copper slag at 10% by weight of fine aggregate up to the optimum value. The concrete mixes were prepared, tested and compared in terms of compressive strength, split tensile strength, modulus of elasticity and modulus of rupture with the conventional concrete. The flexural strength is studied under two point loading and various properties are studied. The resultant in terms of load deflection graph and moment curvature relationship is also studied. The durability properties of the concrete replaced with marble powder and copper slag is found to be in agreement with conventional concrete.

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Thermal Buckling Analysis Of Functionally Graded Plates Using Power Law Function[ ]


Functionally Graded Materials (FGM) are those materials which have continuous variation of material properties from metal phase to ceramic phase. Due to the continuous change in material properties of FGMs, the stress singularity at the interface between the two different materials is eliminated and thus the bonding strength is enhanced. They are widely used in high temperature environment such as nuclear reactors and rocket heat shields. The material property of FGM plate varies along the thickness direction and the variation is idealised by different mathematical idealisation techniques. This paper deals with the buckling behaviour of clamped PFGM plate under linear temperature field. Thermal buckling behaviour of FGM plate has been obtained numerically through ANSYS software. The convergence study of the results is optimized by changing the mesh size. The critical buckling temperature rise obtained for functionally graded plates using ANSYS software are compared with the available literature. The effect of different parameters such as power-law index, thickness ratio, and aspect ratio on critical buckling temperature rise for temperature independent and dependent material properties of each constituent is also discussed.

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Seismic Response Study of RCC Buildings with Elasto-Plastic Viscous[ ]


Supplemental damping devices dissipate earthquake-induced energy through either hysteretic action or viscoelastic or viscous ac-tion. In this work the damping device selected is elasto-plastic viscous damper, which have elasto-plastic and viscous properties. It can be act as both energy dissipating device as well as structural element. The current work presents a framework for studying the effect of elasto-plastic viscous dampers on seismic performance of buildings using SAP2000. 9-storey reinforced concrete building was modeled using SAP2000 software. The modeled building was performed nonlinear time history analysis. Based on the minimum displacement criteria position of dampers has been located. Seismic response of six plan configurations and twelve damper configurations were evaluated. Seismic responses of RCC building with and without elasto-plastic viscous dampers were also investigated.

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Time Period Analysis of Reinforced Concrete Building with and without the Influence of Masonry Infills[ ]


Strength and stiffness are the most important characteristics of any structure. Due to the architectural efficiency of masonry-infilled reinforced concrete frames, the frames are highly common structural forms for buildings. But in the current practice, stiff masonry walls are neglected and only bare frames are considered in design calculations. However, the infills can significantly modify the structural behavior of these frames, which can be detrimental to the seismic performance of buildings. The fundamental period of vibration, dependent on mass and stiffness, is a key parameter in assessing seismic demand. Through this study, the fundamental periods of vibration of RC framed buildings are studied using 3D FE modeling including the effects of infill.

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Pushover Analysis of RC Building[ ]


In this study the seismic response of a ten storied reinforced concrete building is analysed by displacement controlled pushover analysis. It is assumed to be located in seismic zone 3. The building frame is simulated and analysed using the structural analysis and design software SAP2000. In non-linear analysis, moment-curvature relationship is used to model plastic hinge behaviour. Thus it was developed for modelling the user defined hinges for beam and column sections. Moment (M) and interactive P-M hinges were assigned to the both ends of beam and column sections respectively. The lateral forces were obtained as per IS 1893 (Part1):2002 and applied to the building. Top node displacement is incremented step by step up to the limiting displacement to obtain the pushover curve and the sequence of formation of plastic hinges and failure of beams and columns were recorded. The analysis results including the pushover curve and hinge formation are discussed. The maximum base shear capacity was found to be higher than the design base shear and hinges were formed in beams prior to columns.

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Structural Behaviour of Reinforced Concrete Haunched Beam[ ]


Beams are the major structural element that is capable of carrying and transferring load which is designed primarily for bending and shear. A careful approach in its design will lead to efficient use of concrete and steel reinforcement. Prismatic beams are commonly used in medium span beams. As span increase such beams become uneconomical due to increase in depth. In such situation non prismatic beams (haunched beams) are good solution. In the present study the structural behaviour of reinforced concrete haunched beam is studied in ANSYS and ETABS.Comparison of Prismatic and Reinforced concrete haunched beam in terms of displacement and stress intensity has been done by performing nonlinear static analysis in ANSYS.Seismic analysis of RC frames with linear and stepped haunch beams will be studied based on the Time Period, Base Shear and Inter storey Drift.

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Study on Beam-to-Column Connection with Viscoelastic Hysteretic Dampers for Seismic Damage Control[ ]


Dampers are energy-dissipating devices widely applied for new and existing structures in earthquake prone areas. Dampers have become more popular recently for vibration control of structures, because of their safe, effective and economical design. Among the different types of devices, hysteretic dampers are particularly popular due to their simplicity; economy and low cost. A new steel beam-to-column connection for seismic energy dissipation is presented in this paper. In this study viscoelastic hysteretic dampers are utilized along with steel bars at the beam column junction. Installation and repair of the proposed detail are easy to implement as it consists of placing a viscoelastic damper as a lower pad on the seat angle of the connection and a series of bolts connecting the top flange to the seat angle. Effects of various parameters on the behavior of the proposed connection will be studied comprehensively.

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Ultimate Strength Analysis of Highly Damaged Plates[ ]


Thin plate structures are efficient structures because of their high load-carrying capacity and small weight. Thin plates are one of the common structural elements. Their load-carrying capacity mainly depends on their buckling behavior, which is in turn affected by the imperfections present in them. Dent is one of the common geometrical imperfections in thin shell structures, which may be formed in the plate as an impact of sharp objects, among other reasons. This work deals with the ultimate compressive strength of highly damaged plating resulting from dropping objects, grounding or collision. Extensive static nonlinear finite element analyses were conducted using ANSYS. The effect of dent depth as well as dent size were studied. Different dent shapes are considered in order to cover different possible damage scenarios.

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Study on Performance of Diagrid System on High Rise Buildings with Complex Shape[ ]


Diagrid structures for tall buildings are very popular among engineers and architects. One of the evocative structural design solutions for sustainable tall buildings is embraced by the diagrid structural scheme. This study focuse on the concept of diagrid structural system, structural performance of a steel tall building and compare the complex shape of high rise building for diagrid system using SAP2000. The resulting diagrid structures were assessed under gravity, wind and seismic loads and various performance parameters were evaluated on the basis of the analysis results. The comparison is in terms of lateral displacement and inter storey drift.

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Axisymmetric Solid with Non-Axisymmetric Load Using Matlab[ ]


In general rocket structural configurations are symmetric with respect to axis. Most of the situations the loading that comes on the structures are also symmetric. This makes the problem simple since axi-symmetric solid with axi-symmetric loading can be used for the structural analysis. But there are special situation where loading alone is not symmetric, it may be mechanical or thermal. To solve such a problem either three dimensional solid element can be used with loading at the appropriate locations. This will provide the complete solution at the expense of extra time on modeling and computation cost. This can be solved by another way where modeling of structural configuration becomes 2D but the non-axisymmetric load has to be expressed in the Fourier series form. Using this Fourier series, solution has to be obtained for each Fourier component. This solution can be obtained using two dimensional configurations. The total solution can be obtained by adding the solution obtained for each Fourier coefficient. Using the total solution, solution at desired angle can be obtained. The solution can be in the form of displacements, strains and stresses and reaction at the support points. This procedure considerably reduces the computation cost and modeling effort. It is proposed to develop finite element code using MATLAB for mechanical load. The results obtained with present code is validated with commercially available finite element software.

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STRUCTURAL ANALYSIS OF VISCOELASTIC SOLID PROPELLANT GRAIN[ ]


A solid propellant rocket is a simple form of chemical propulsion. The fuel and oxidizers are both incorporated in a single solid called propellant grain located inside the combustion chamber. Solid rocket motor structural design is currently based on concept of mechanically weak solid propellant grain casted into a stronger metallic case wrapped with insulation and casing. Solid rocket motor is subjected to various loading during transportation, storage and firing. The finite element method has the capability to deal with the complex structure, material behavior and geometrical properties. Standard displacement finite element formulations for structural analysis are ill conditioned when Poisson's ratio nearly equals to 0.5. Hence for viscoelastic analysis, a special formulation is required as the propellant is nearly incompressible.

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Finite Element Analysis of Pressure Vessels and Joints using FEASTSMT/PreWin and NISA/DISPLAYIII[ ]


Solid Rocket Motors (SRM) serve as the propulsion back-bone for strategic and tactical missiles as well as satellite launch vehicles. Motor case joints are mainly designed in SRM to prevent hot gas leakage and to reduce gap opening moments, the analysis of which can be incorporated with good accuracy using Finite Element Method (FEM). The flanged joint, segment joint and end dome to igniter joints are some of the important joints which are analysed to obtain its structural behavior. Estimation of stress in bolt under prestress, the structural deformations, the sealing of the O-ring to prevent the hot gas in segment joints and maximum stresses in joints and the walls is done using software FEASTSMT/PreWin (Finite Element Analysis of Structures). FEAST is ISRO's structural analysis software based on FEM realized by Structural Engineering entity of Vikram Sarabhai Space Centre (VSSC). The reliability of the software is established by comparing the analysis results of pressure vessel having different joint types with the results on another FEM software NISA/DISPLAYIII.

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BEHAVIOR OF HYPERBOLIC PARABOLOID SHELL FOOTINGS UNDER POINT LOADING[ ]


The Hypar shell is a doubly curved, non-developable anticlastic shell of translation with ruled surfaces, having straight line property. They were introduced in foundations in order to transmit highly concentrated loads to weaker soils. In this work the non-linear static analysis of Hypar shell foundation is carried out using ANSYS 15 WORKBENCH software. The Hypar shell with varying rise of shell to lateral dimension ratio as 0.25, 0.5, 0.6, 0.7 and 0.85 is considered. The staticanalysis is carried out for loose sand and medium clay with bonded and smooth contact between soil and shell. Settlements and stresses were analysed in this research. The results were compared with rectangular footing. For both stress and settlement hypar is showing better performance than rectangular footing.

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Assessment of Soil Structure Interaction and Vibration Analysis of A Tower Structure[ ]


Steel tower structure resting on piles are currentlybecoming popular in any geographical location for electrical transmission,microwave mobile transmission etc. when such structures are used in earthquake prawn areas they have to perform without any problem even during times of disaster due to their importance in communication,power supply etc.Hence it is necessary to have an understudy of the behaviour of such structure and provide an economical design.to understand the performance of such structures is necessary to know their behaviour considering soil structure interaction.In this work a steel tower structure resting on single pile at each leg and group of three piles embedded in soft, medium and stiff soil has been analysed to obtain their stresses and deformations. The modal analysis, static analysis and transient structural analysis considering the kobe earthquake has been considered. The result pointed out that the soil structure interaction is important and need to be accounted to reach a realistic understanding of such structures.

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Free Vibration Analysis of Delaminated Honeycomb Sandwich Composite Plates[ ]


A composite material is a material made from two or more constituent materials with significantly different physical or chemical properties that, when combined, produce a material with characteristics different from the individual components. Sandwich construction is one of the most valued structural engineering innovations developed by the composite industry. The present study aims on damage detection of sandwich plates based on free vibration analysis. To detect, localize and quantify the damage, modal parameters- frequency and mode shapes are used. ANSYS is used for the finite element analysis. An intact model is analyzed first and the results of the debonded one is compared with the intact one. It is observed that decrease in natural frequency of a debonded plate in comparison with that of an intact one gives an indication of the damage.Here a meaningful parameter called Modal Strain Energy Change Ratio (MSECR)is used to predict the position and extent of damage.

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Lateral Torsional Buckling Behaviour Of Cold-Formed Light Gauge Steel Flexural Member With Triangular Shaped Web Corrugation[ ]


The light gauge steel sections are formed by cold forming technique, it results in thinner section which may be more liable to buckle in different manner, which was basically a serious issuewhen it is used as a structural member. This paper is concerned with the study of lateral-torsional buckling behavior of cold formed light gauge steel beam with triangular shaped corrugations on the web by using Finite element software ANSYS. The strength of which under lateral torsional buckling are determined first by linear Eigen value buckling analysis by considering linear stress-strain behaviour. Then a non linear buckling analysis was performed for getting actual deformation and twisted profile by incorporating non-linear material properties. The analytical results obtained were compared with beam having Flat web.

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Nonlinear Analysis of High Damping Rubber Bearing with Different Material & Geometry[ ]


High damping rubber bearings are amongst the most commonly used devices for seismic isolation. Components of laminated rubber base isolator are a flexible material and a reinforcing material. Conventionally used reinforcing material is steel. Nowadays different fibre reinforced polymers (FRP) which have strength comparable to steel are developed. By replacing steel by FRP sheets, we can have the advantage of light weight and easier manufacturing of different geometry. The isolation efficiency and cost can be optimized by considering material, geometry, orientation of fibres in FRP sheets and changing the design parameters. Here, nonlinear finite element analysis is conducted on high damping rubber isolators with steel and CFRP in 3 different geometry using ANSYS under vertical and lateral load.

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Evaluation of the Properties of Bentonite Concrete with and without Steel Fiber[ ]


Concrete is a major building material which is been used in construction industry throughout the world. It is an extremely versatile material and can be used for all type of structures. If bentonite is used for the partial replacement of cement, thus concrete becomes inexpensive and eco-friendly. This paper present the result of an experimental investigation carried out to evaluate the properties of concrete with bentonite and steel fiber bentonite in which ordinary portland cement was partially replaced with bentonite by weight for a mix of M30 grade concrete. Firstly, Workability, Compressive strength, split tensile strength and flexural strength of concrete were evaluated at different percentages of bentonite. Secondly, the same properties were examined in concrete adding different percentages of hooked end steel fiber by weight of concrete with constant amount of bentonite which in turn increases the strength of concrete.

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Effect of Temperature Variation on Compressive Strength of Concrete with Crushed Ceramic Tile Aggregate and Glass[ ]


The present paper investigates the effect of temperature variation on compressive strength of Crushed Ceramic Tile Aggregate (CCTA) and Glass Fibres (GF) incorporated concrete. Compressive strength of concrete is studied with replacement of natural coarse aggregate by CCTA at 0, 25 and 50 % and GF (1 %). The hardened concrete specimens after curing in water for 28 days were thermally treated at 150 and 300 ï‚°C for 2 hours. The heated specimens are cooled in air and water. The compressive strength of specimens before and after subjecting to elevated temperature was compared with those of the control specimens. The results showed that the addition of CCTA and GF improves the performance of concrete when exposed to elevated temperatures. Strength attained was higher for air cooling than for water cooling.

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DYNAMIC ANALYSIS OF MINI TENSION LEG PLATFORMS UNDER RANDOM WAVES[ ]


Mini Tension Leg Platform (TLP) is a new generation TLP of relatively low cost, developed for the economic exploration and extraction of hydrocarbons from marginal deepwater oil fields. It can also be used as a utility, satellite, or early production platform for larger deepwater discoveries. The development of the mini TLP concept illustrates the advancement of offshore technology venturing into deeper water depths at not so exorbitant costs. The ease in fabrication and installation is another advantage of the mini TLP over the conventional TLP. These offshore structures should be able to withstand the dynamic effects of environmental loads during their lifetime. These loads range from temporary/transient loads induced by earthquakes and sea storms to continuous (or stationary) loads due to wind, waves, and sea currents, among others. To design and construct offshore structures, including floating ones, against various environmental loads, the response of structures to these loads should be understood. This paper deals with the detailed numerical investigations of the dynamic behaviour of a mini TLP under random waves. The numerical study has been carried out using the finite element software ANSYS AQWA using diffraction theory.

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VIBRATION CONTROL OF TENSION LEG PLATFORMS USING MASS DAMPERS UNDER RANDOM WAVES[ ]


An offshore structure may be defined as one, which has no fixed access to dry land and which is required to stay in position in all weather conditions. A tension leg platform is a compliant offshore structure which allows lateral movements of surge, sway and yaw but restrains heave, pitch and roll. Due to the cost effectiveness of TLP in deep sea, they are favoured by the offshore industry. These offshore structures should be able to withstand the dynamic effects of environmental loads during their lifetime. TLP drift motions (surge–sway–yaw motion), due to the action of wave forces, can be significant during extreme weather conditions. These motions could affect the performance during operation and maintenance. Damping devices integrated into the TLP structure could improve the response characteristics, as they have been proved to be beneficial in reducing the vibrations in civil engineering structures. This paper deals with the detailed numerical investigations of the dynamic behaviour of a TLP using mass dampers under random waves. The numerical study has been carried out using finite element software ANSYS AQWA using diffraction theory.

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EFFECT OF VERTICAL IRREGULARITIES ON SEISMIC PERFORMANCE OF RC BUILDINGS[ ]


During an earthquake, failure of structure starts at points of weakness. This weakness arises due to discontinuity in mass, stiffness and geometry of structure. The structures having this discontinuity are termed as Irregular structures. The behaviour of a building during an earthquake depends on several factors such as stiffness, adequate lateral strength, ductility and configuration. The buildings with regular geometry and uniformly distributed mass and stiffness in plan as well as in elevation suffer much less damage compared to irregular configurations. Regular buildings have uniformly distributed mass, stiffness, strength and structural form. When one or more of these properties is non-uniformly distributed, either individually or in combination with other properties in any direction, the structure is referred to as being irregular. Irregular structures contribute a large portion of urban infrastructure. Vertical irregularities are one of the major reasons of failures of structures during earthquakes.

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Behaviour of Concrete Filled Fiber Reinforced Polymer Tube under Blast Loading[ ]


In recent years, the public concern about safety has increased dramatically because of the tremendous increase in the number of explosive industrial accidents and terrorist attacks all over the world. Due to the threat from such extreme loading conditions, efforts have been made to develop methods of structural analysis and design to resist blast loads. Studies were conducted on the behavior of structural concrete subjected to blast loads. Improvement to existing construction methods that enhance blast resilience can ultimately save lives and property. Concrete filled FRP tubes (CFFTs) are known to improve a conventional reinforced concrete member’s resistance to traditional loads by strengthening, protecting, and confining the reinforced concrete core. This paper outlines a numerical model built using commercially available software AnsysAutodyn to predict the response of concrete filled fiber reinforced polymer (FRP) tubes (CFFT) and determine the factors influencing their response. The comparison of dynamic behaviour CFFT and reinforced concrete (RC) column under blast loading has done. From the study it is clear that CFFT is more blast resilient than RC column. The parametric study was done on the effect of standoff distance and charge weight.

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Investigations on Concrete with Recycled Concrete as Coarse Aggregate[ ]


In India, a huge quantity of construction and demolition wastes are produced every year. These waste materials need a large place to dump and hence the disposal of these wastes has become a problem. Also the continuous use of natural resources for making conventional concrete leads to the reduction in their availability and results in the increase of the cost of the aggregates. When recycled coarse aggregate is used in structural concrete, the assessment of physical, mechanical and durable characteristics are very important. The physical and mechanical properties of natural aggregate and recycled aggregates are characterised. The experimental investigation was done on different grades of concrete (M25 and M35). A control specimen was created with 0% of recycled aggregates and this specimen was compared with different concrete mixes of different percentages of recycled aggregates. Recycled coarse aggregate is added in different amounts such as 20%, 40%, 60%, 80% and 100%. Cube compressive strength, cylinder compressive strength and split tensile strength of concrete made with recycled concrete aggregates are evaluated. A total of 72 cubes (150 mm), and 108 cylinders (150 mm diameter and 300 mm height) are used to determine the compressive strength and tensile strength. As the amount of RCA added is increased, the strength of the specimen decreased proportionally. Properties of materials used for the thesis were found out by doing several lab tests. The properties of recycled concrete aggregate are similar to the properties of natural aggregate. Thus, the possible use of RCA at this optimum amount helps to conserve natural resources and reduces the land needed for the disposal of waste aggregates.

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STUDY ON STRESS RELATIONSHIPS OF CURVED SPACE TRUSS[ ]


Space truss is a most commonly using type of truss for roofing in the structures like auditoriums, stadiums and such big structures nowadays. Curved Space truss is the most commonly using type. Main reason for this is that, it can be used for long span trusses by reducing the intermediate supports. Use of this type of trusses in different structures have different structural properties and structural behavior. One of them is the depth and span relation. For different structures, this will be different. Also due to that, the stress- strain relationship is a factor that is having considerable importance. By knowing this, we can improve different properties of the truss system and that will give economy to the work, strength to the structure etc. Many models of Space Truss were made with different geometry and dimensions that having different Span-Depth ratio. Material properties, Support conditions, loading conditions etc. were assigned properly and uniformly. Modelling and Analysis were done using STAAD Pro. Software. Larger value of Stress from Stress report after analysis were collected from each models. Optimum value of stress were noted corresponding to Span – Depth ratio of different models. Studied these results and relations. It will help us to get an idea to fix the curvature of this type of truss for different span with particular geometry.

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Experimental Study on Glass Fiber Reinforced Gypsum (GFRG) Panels Filled with Alternate Concrete Mix Using Shredded Thermocol and Phosphogypsum[ ]


Glass fiber reinforced gypsum panels (GFRG) are hollow panels made from modified gypsum plaster and reinforced with chopped glass fibers. The hollow cores inside the walls can be filled with in-situ concrete/reinforced concrete or insulation material to increase the structural strength or the thermal insulation, respectively. GFRG panels can be unfilled when used as partition walls, but when used as load bearing walls, it is filled with M20 grade concrete (reinforced concrete filling) in order to resist the gravity and lateral loads. The study was conducted in two stages: First stage involves formulation of an alternate light weight mix to be used in the GFRG panels in lieu of M20 grade concrete by partial replacement of cement with phosphogypsum and fine aggregate with shredded thermocol and thereby conducting experimental investigations to obtain the optimum combination. In the second stage the above formulated mix is filled in GFRG panels and experimental investigations are conducted to evaluate the strength parameters and the results are compared with the panels filled with conventional M20 concrete mix. The results of the second stage of experimental investigations are presented in this paper

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Quantificationof Damage Due to Earthquakeon RCC Multistoried Building with Different Shear Wall Locations[ ]


The quantification of damage to reinforced concrete buildings due to earthquakes has utmost importance in earthquake engineering community. This can be achieved with the help of damage indices like Vulnerability Index. These damage indices evaluate structural stability under seismic loading and quantify local and global structural damage of buildings, subject to base excitations. Shear walls are commonly used as a vertical structural element for resisting the lateral loads that may be induced by the loads due to wind and earthquake. A well designed system of shear wall in building frame improves

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PERFORMANCE ASSESMENT OF RC BUILDING FRAMES BY NON LINEAR ANALYSIS[ ]


Recent earthquakes in which many concrete structures have been severely damaged or collapsed, have indicated the need for evaluating the seismic adequacy of existing buildings. About 60% of the land area of our country is susceptible to damaging levels of seismic hazard. One of the procedures is the nonlinear static pushover analysis which is becoming a popular tool for seismic performance evaluation of existing and new structures. By conducting this pushover analysis, we can know the weak zones in the structure and then we will decide whether the particular part is to be retrofitted or rehabilitated according to the requirement. In the present study the push over analysis is performed on RC building frames by changing the footing, infill wall, aspect ratio and introduction of bracings on the SAP2000 (version 14). These four features have the capacity to increase the seismic performance of the building and the bracings can be used for retrofitting for buildings which are structurally weak

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Analysis of Skew Bridge with Varying Skew Angles[ ]


Many highway bridges are skewed and their behavior and corresponding design analysis need to be furthered to fully accomplish design objectives. The research deals with the finite element modeling of simply supported skew slab with varying skew angles using ETABS 2013 software. The behavior of the simply supported skew slab under point load applied at the center depends on the ratio of short diagonal to its span. In the theoretical study, the skew angle and the concrete grade had a significant influence on the overall behavior of the slab. The simply supported skew slab is analyzed with a concentrated load at the center and knife edge load. The analysis is done on the varying span length and the skew angles. Moment, shear force and Torsional variations are analyzed. The research deals with the design of skew bridge with suitable skew angle. The bending moments in the concentrated load condition and the knife edge load condition are decrease up to 65% and 75% respectively as the skew angle increases to 600. The increment of torsional moments is of 60% in both the conditions.

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Importance of Plinth Beams on the Seismic Response of Rc Moment Resistant Frames[ ]


Base flexibility of structures affects the force and displacement demands on frame elements during earthquakes. Rotational restraint at column bases can be increased by providing plinth beams. This study evaluates the effects of plinth beams at various heights from the base on the seismic response of RC moment resistant frames. Six storey buildings with different column base flexibility conditions such as fixed base, hinged base and hinged base with plinth beams were considered for the analytical study. Plinth beams provided at the base and various heights from the base such as 0.5m, 1m and 1.5m. Pushover analysis and response spectrum analysis were performed on the building models using ETABS 2013 software. Providing a plinth beam between ground storey column helps in controlling the seismic demands in RC frame buildings and plinth beams at 1.5m height from the base shows maximum shear force demand and less bottom storey displacement.

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Parametric Study on CFST Column – Steel Beam Connection Under Cyclic Loading[ ]


This paper deals with the finite element modelling of a CFST column- steel I beam connection with external diaphragm (external stiffener) in ANSYS. Five finite element models of CFST column – steel beam connection with different tube thickness are modeled and named as J1, J2, J3, J4 and J5. The models are analysed under a constant axial load on the CFST column and a cyclic load at the steel beam. The stress distribution in the diaphragm, column, and in the steel beam is studied in different cycles. As the steel tube thickness of CFST column increased there is a considerable reduction in the area under different stress range in steel tube. The maximum compressive principal stress in concrete is reduced due to the increased confinement provided by the steel tube. In the entire five models the failure was reported in the beam indicating a weak beam strong column connection.

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Shear Behavior of Corrosion Induced Reinforced Concrete Beams Retrofitted with Ferrocement Jackets[ ]


Corrosion of reinforcement steel in reinforced concrete structures affects the long term performance RC structures are originally designed for. Only limited studies have been conducted to investigate the shear behavior of corrosion induced reinforced concrete beams. This study investigates the shear behavior of retrofitted corrosion induced reinforced concrete beams. For this, twenty four shear deficient beams of size 100x150x1000mm using M20 concrete are prepared. The specimens have been subjected to various percentages of corrosion, 5%, 10% and 15% of mass loss of steel reinforcement. The beams to be retrofitted, after corrosion, are subjected to preloading up to 67% of the respective ultimate load bearing capacity. They were then retrofitted at the shear spans by means of U-wrap ferrocement, containing two layers of woven wire mesh. All the beams are tested in UTM and subjected to two- point loading. The ferrocement U- wrap containing two layers of welded wire mesh increased the load bearing capacities and hence has proved efficient in restoring the strength of the beams.

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Comparison of Flexural Behaviour of Functionally Graded Plates Using Higher Order Shear Defor-mation Theory with Different Homogenization Schemes[ ]


Functionally graded materials are one of the most widely used materials in various applications because of their adaptability to different situations by changing the material constituents as per the requirement. The properties of functionally graded plates can be defined by using different homogenization methods like Simple power law distribution, rule of mixtures, Mori-Tanaka homogenization scheme, sigmoid function exponential distribution function etc. In the present study the power law, Mori-Tanaka scheme and exponential distribution is considered for the volume fraction distribution of functionally graded plates. The flexural behavior is studied for different homogenization schemes and obtained results are compared with the available literatures. The basic formulations for the FGM plate are done based on the third order shear deformation theory. All the numerical examples are done using MATLAB programs.

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Seismic Behaviour of Tall Buildings with and Without In-Fill Walls[ ]


The design of masonry in-fills is an issue that has attracted the attention of several researchers in the past, both from the expe-rimental and analytical points of view. Nevertheless, the results are often questionable due to the large variability of masonry properties. Presence of in-fill walls in the frames alters the behaviour of the building under lateral loads. However, it is common industrial practice to ignore the stiffness of in-fill wall for analysis of framed buildings. In this paper, seismic analysis of multi-storeyed building for different plan configurations like rectangular, C, L and I-shapes is mainly emphasized. The building was analysed for seismic zone V of IS 1893-2002. The building was analyzed for four different cases a) without considering in-fill wall, b) considering brick masonry in-fill wall. Modelling of 15- storeys R.C. framed building is done on the ETABS software for analysis. In-fill stiffness was modelled using a diagonal strut approach. Response spectrum analysis is carried out for the models and the results were compared.

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Study OnDeep Beam With Web Openings[ ]


RC deep beams are structural elements loaded as beam in which significant amount of load is transferred to the support by compression thrust line joining the loads and reactions. As a result the strain distribution is no longer considered linear and shear deformation become significant when compared to pure flexure. The provision of opening in the web of deep beam is usually required to accommodate essential services such as air conditioning ducts and electricity cables or to provide accessibility such as doors and windows. Several studies are done for providing openings in the deep beam. This paper deals with to find the exact position, size shape of the openings.

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A Study on Vibration Control of Framed Struc-tures Due to Seismic Excitation Using Tuned Mass Damper[ ]


Current trends in construction industry demands taller and lighter structures, which are also more flexible and having quite low damping value. As a result these structures will be subjected to vibrations of larger amplitudes under earthquake. This increases failure possibilities and also problems from serviceability point of view. Tuned Mass Damper (TMD) is a passive control device which absorbs energy & reduces response of vibration. This paper addresses the usefulness of incorporating soft storey to function as TMD in controlling the structural response. An attempt is made to find the effective mass ratio which gives the least displacement of the building. Here a six storeyed regular building is proposed to be analysed using SAP2000 v 16 with Tuned Mass Dampers (TMD) and without any damping device. Tuned Mass Dampers with varying mass ratios of 2%, 3% and 5% was applied. Non-linear time History Analysis was carried out by applying standard earthquake ground accelerations. A comparative study was done.

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Study on seismic behavior of dual systems in high seismic zones[ ]


In present days flat slab buildings are widely used due to the advantage of reduced floor heights to meet the economical and architectural demands. Analysis and design of flat slab buildings for gravity loads are well established. These structures are more vulnerable to seismic and other lateral loads. Performance of flat slab buildings is unsatisfactory. However flat slab buildings are also being constructed in high seismicity region which can cause collapse of the buildings under seismic loading. Shear walls are added to the structures to improve its behaviour in seismic loading. In this paper, performance of shear wall provided at different positions of flat slab structure is studied. The analysis is done in Etabs. G+3, G+8, G+12 storeyes are considered for the analysis. Seismic zone IV and soil type II is considered. The response parameters such as lateral displacement, time period, storey drift, and base shear were evaluated.

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Analysis of Circular Steel Diagrid Buildings with non-Uniform Angle Configurations[ ]


Tall commercial buildings are primarily a response to the intense pressure on the available land. Advances in materials, construction technology, analytical methods and structural systems for analysis and design accelerated the development of tall structures. The lateral loading due to wind and earthquake is the major factor that causes the design of high-rise buildings. These lateral loads are resisted by exterior structural system or interior structural system. Diagrid is an exterior structural system emerging as structurally efficient as well as architecturally significant assemblies for tall buildings. Diagrid eliminated all vertical columns and consists of only inclined columns on the façade of the building. Shear and over-turning moment developed are resisted by axial action of these diagonals compared to bending of vertical columns in framed tube structure. These inclined columns or diagonals have an optimal angle at which the structural capability of the member is optimized for both gravity and lateral loadings. In this paper, circular buildings configured with uniform diagonal angle are compared to buildings with non-uniform diagrid angle distribution. A regular plan diameter of 40.63 m was considered for the building. ETABS software is used for modelling and analysis of structural members. 36, 50, 60, 70 and 80 storey buildings are modelled with uniform and non-uniform diagrid angle configurations. Dynamic wind analysis have carried out as per Gust effect factor method of IS:875 Part III- 1987. Comparison of analysis results in terms of top storey displacement and maximum forces developed on the diagrid member is presented in this paper.

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DYNAMIC CHARACTERISTICS OF LARGE REINFORCED CONCRETE ELLIPSOIDAL DOMES[ ]


According to the Indian seismic zone map, 59% of the Indian land area is under earthquake threat. Especially the North Eastern part adjoining the Himalayan belt. Over the last 15 years, 10 major earthquakes occurred in these regions, resulting in over 20 000 deaths. Several scientific publications warns the likeliness of the occurrence of severe earthquakes in these regions. Large span reinforced concrete domes with different shapes (spherical, ellipsoidal and paraboloidal) are commonly used as roof structures, especially in public buildings and places of worship. Behavior of reinforced concrete domes of large span under earthquake loads and the interaction between these domes and the adjoining structure is not well studied. This issue never received much attention by the research community due to the scarcity of such structures worldwide. To assess the seismic vulnerability of buildings with large domes, the dynamic characteristics and behavior of large reinforced concrete domes need to be studied and their susceptibility to damage need to be evaluated. This paper, specifically presents a study of reinforced concrete ellipsoidal domes and the effect of the variation of their thickness and height on their dynamic characteristics such as frequencies of vibration. The results obtained for ellipsoidal domes are compared with that available for spherical and paraboloidal domes from previous study.

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