INTERNATIONAL JOURNAL OF CIVIL AND STRUCTURAL ENGINEERING
VOLUME 2, NO 2 - 2011
ABSTRACTS
A comparative study of Bamboo reinforced concrete beams using different stirrup materials for rural construction
Author(s)- Adom-Asamoah Mark, Afrifa O.Russell
ABSTRACT
This study aims at exploring ways of making the use of bamboo reinforced concrete beams simple, efficient and cost-effective for rural construction with Ghana as a case study. It is a comparative study of bamboo reinforced concrete beams with shear links made of different materials. The web materials considered were bamboo, rattan cane and steel. Sixteen (16) beams were tested to failure under four point bend tests. The highest and lowest failure loads were recorded for the cases of steel stirrups and no stirrups respectively. The experimental failure loads averaged 5.05 and 1.72 times the observed first crack and theoretical failure loads respectively. At failure, beams with low concrete compressive strength and small amount of bamboo tension reinforcement had wider cracks. The cheapest and most economical means of providing shear reinforcement for bamboo-reinforced beams was analysed using a performance model developed in this research. A beam performance index (BPI) in terms of energy absorbed per unit cost of beam, indicated the use of steel stirrups as the most economical. The most expensive means of shear reinforcement provision in bamboo reinforced beams is by rattan cane stirrups irrespective of the grade of concrete. It is therefore recommended that steel stirrups be used to enhance the performance of bamboo reinforced concrete beams.
Development of Cement Grout mixes for treatment of underground cavities in Kuwait
Author(s)- Kamal H., El-Hawary M., Abdul-Jaleel A., Abdul-Salam S., Taha M
ABSTRACT
Large sinkholes occurred in a residential suburb in the State of Kuwait, leading to destruction of properties and subsequently to partial evacuation of this residential area. From comprehensively conducted investigation programs, the sinkholes were attributed to the existence and propagation of Karst cavities in the limestone bedrock layer. Accordingly, a complete treatment program was adapted to reduce the risk of sinkhole recurrence by minimizing the possibilities of collapse in the upper level cavities within the limestone bedrock. In this project, two different cement grout mixes were designed and used for treatment of the Karst cavities; cavity filling grout and permeation grout. The assessment of the used mixes included regular evaluation of the compressive strength, slump, thermal conductivity, thermal resistance, bleeding, air content, loss of slump, flow and setting time. The treatment was followed by an evaluation program by drilling control boreholes. Some cores of the hardened grout were extracted from the control boreholes and their properties were evaluated and compared to those of laboratory specimens. This paper describes different types and mixes of cement grouts utilized in the ground treatment, elements of quality control program, and frequency and types of tests. Assessment of the results in addition to overview of the project is also presented. The results verified the efficiency of the different cement grout mixes used in this treatment project.
Mechanical Properties for High Performance Concrete Exposed to High Temperature
Author(s)-Saeed Ahmed Al.Sheikh
ABSTRACT
This paper deals with the development of engineering database on the changes in the mechanical properties of high performance concretes mixtures when exposed to high temperature up to 1000oC. The results of an experimental investigation in to the effects of high temperature on the residual compressive and tensile strengths for high performance concretes made with ordinary Portland cement are presented. Concrete specimens were heated in an electric furnace to varying temperatures up to 1000oC and the change in compressive and tensile strength, weight, ultrasonic pulse velocity and rebound number were determined. The heated specimens were subjected to sudden cooling in water and to slow cooling in air. The results showed that the compressive and tensile strengths, pulse velocity and rebound number were decreased with the increase in exposed temperature. The weight loss from concrete increased non- linearly with the maximum exposed temperature. Sudden cooling caused reduction in concrete strength.
Nonlinear Seismic Behavior Evaluation of Ductile Beam-Column Connections in Precast Concrete
Author(s)-Hassan Jafarian, Khosrow Bargi
ABSTRACT
In this paper, a nonlinear finite element (FE) analysis of ductile concrete connections is presented. However, due to the inherent complexity of beam–column joints and the unique features of the tested specimens, the experimental study was not comprehensive enough. Therefore, in this paper, an analytical investigation based on the FE models and using the ANSYS software is presented to examine the effectiveness of a precast beam-column concrete connection of a jointed system. The critical parameters influencing the joint’s behavior, the axial load on column, are varied and their effects are studied.
Analysis of Flanged Shear Wall Using Ansys Concrete Model
Author(s)- Greeshma S, Jaya K P, Annilet Sheeja L
ABSTRACT
The frequent occurrence of the major earthquakes in the Indian subcontinent, and construction of tall buildings, especially over the last two decades demands for the construction of earthquake resistant buildings. Many of the tall buildings had collapsed in recent earthquakes and the reasons attributed were poor design and construction practices. The objective of this work is to discuss the possibilities of modeling reinforcement detailing of reinforced concrete models in practical use. To carry out the analytical investigations, the structure is modeled in a Finite Element software ANSYS. The specimens are modeled as (i) discrete model and (ii) smeared model. It reports the results of the analysis of the flanged shear wall with two different types of modeling under cyclic loading. The consequences of small changes in modeling are discussed and it is shown that satisfactory results are obtained from the two models.
Analysis of Flanged Shear Wall Using Ansys Concrete Model
Author(s)- Greeshma S, Jaya K P, Annilet Sheeja L
ABSTRACT
The frequent occurrence of the major earthquakes in the Indian subcontinent, and construction of tall buildings, especially over the last two decades demands for the construction of earthquake resistant buildings. Many of the tall buildings had collapsed in recent earthquakes and the reasons attributed were poor design and construction practices. The objective of this work is to discuss the possibilities of modeling reinforcement detailing of reinforced concrete models in practical use. To carry out the analytical investigations, the structure is modeled in a Finite Element software ANSYS. The specimens are modeled as (i) discrete model and (ii) smeared model. It reports the results of the analysis of the flanged shear wall with two different types of modeling under cyclic loading. The consequences of small changes in modeling are discussed and it is shown that satisfactory results are obtained from the two models.
A study on characterization and use of Pond Ash as fine aggregate in Concrete
Author(s)- Arumugam K, Ilangovan R, James Manohar D
ABSTRACT
This experimental study is to investigate the possibility of using pond ash in varying percentage as fine aggregate substitute in cement concrete. During the combustion of pulverized coal at the thermal power station the product formed are bottom ash, fly ash and vapours. There bottom ash is that part of residue which is fused into particles and is collected at the bottom of the furnace. The distribution between bottom ash and fly ash fraction is a function of burner type, type of coal and the type of boiler bottom (wet or dry). In India most of the thermal power plants adopt wet method of ash disposal. The fly ash collected from Electrostatic precipitator and the bottom ashes are with water and disposed in a slurry form in large ponds and dykes. Fly ash acts both as a fine aggregate and as a cement. Pond ash differs from fly ash collected from Electrostatic precipitators in a dry form in that it contains significant amount of relatively coarser particles (greater than 45 µm and up to 150 µ m). The above study is to be discussed with the workability and compressive strength of concrete and is to be compared with standard concrete.
Effect of Nano- Flyash on Strength of Concrete
Author(s)- Prince Arulraj.G, Jemimah Carmichael.M
ABSTRACT
The use of nano-particles in developing materials with desired properties has gained popularity and is being applied in many fields. More specifically, such particles can lead to improvements in the nanostructure of building materials such as cement and concrete. Concrete technology is a multidisciplinary area of research where nanotechnology potentially offers the opportunity to improve the properties of concrete to suit the specific requirements. Recent research has shown that addition of nanoparticles and nanotubes depends in the properties of concrete by modifying the structure of cement hydrates. It is also reported that addition of nano materials to concrete can lead to significant improvements in the strength and life of concrete. The grain size of the nano particles will be in the order of 10-9 m (1-100nm) (1). An attempt has been made to carry out an experimental investigation on concrete with nano-fly ash. Class F fly ash was grinded in the ball grinding mill to produce nano-fly ash(5). Different grades of concrete viz., M20, M30. M40 and M50 were cast with nano-fly ash. For each grade of concrete, 10%, 20% and 30% of coarse aggregate was replaced with nano-fly ash. The workability and compressive strength of concrete with nano-fly ash were determined and the results were compared with that of Normal Cement Concrete (NCC). Concrete with nano-fly ash was found to be stronger than NCC and the percentage increase in strength of concrete with nano-fly ash with respect to NCC was found to be in the range 17% to 50 % for various grades of concrete. The workability of concrete with nano-fly ash was found to be significantly more than that of NCC.
Performance of steel fiber on standard strength concrete in compression
Author(s)- Prashant Y.Pawade, Nagarnaik P.B., Pande A.M.
ABSTRACT
In this investigation a series of compression tests were conducted on 150mm, cube and 150mm x 300mm, cylindrical specimens using a modified test method that gave the complete compressive strength, static, dynamic modulus of elasticity, ultrasonic pulse velocity and stress-strain behavior using silica fume with and without steel fiber of volume fractions 0, 0.5, 1.0, and 1.5 %, of 0.5mm Ø of aspect ratio of 60 on Portland Pozzolona cement concrete. As a result the incorporation of steel fibers, silica fume and cement has produced a strong composite with superior crack resistance, improved ductility and strength behavior prior to failure. Addition of fibers provided better performance for the cement-based composites, while silica fume in the composites may adjust the fiber dispersion and strength losses caused by fibers, and improve strength and the bond between fiber and matrix with dense calcium-silicate-hydrate gel. The results predicted by mathematically modeled expressions are in excellent agreement with experimental results. On the basis of regression analysis of large number of experimental results, the statistical model has been developed. The proposed model was found to have good accuracy in estimating interrelationship at 28 and 90 days age of curing. On examining the validity of the proposed model, there exists a good correlation between the predicted values and the experimental values as showed in figures.
Solution of Shear Wall Location in Multi-Storey Building
Author(s)- Anshuman. S, Dipendu Bhunia, Bhavin Ramjiyani
ABSTRACT
In this paper, therefore, main focus is to determine the solution for shear wall location in multi-storey building based on its both elastic and elasto-plastic behaviours. An earthquake load is calculated and applied to a building of fifteen stories located in zone IV. Elastic and elasto-plastic analyses were performed using both STAAD Pro 2004 and SAP V 10.0.5 (2000) software packages. Shear forces, bending moment and story drift were computed in both the cases and location of shear wall was established based upon the above computations.
Experimental study on Cold Bonded Fly Ash Aggregates
Author(s)- Priyadharshini.P, Mohan Ganesh.G , Santhi.A.S
ABSTRACT
Many researches have been carried out in the area of fly ash utilization in the past. It mainly concentrated on replacement of cement with fly ash but production of artificial aggregates with fly ash helps in utilizing large volume of ash in concrete. The world is much interested in this part recently due to this large-scale utilization which also reduces environmental pollution and dwindling of natural resources. This paper mainly focuses on manufacturing process of light weight aggregates using pelletizer and curing has been done in cold bonded technique. The properties of these fly ash aggregates have been tested and compared with natural gravel and the study shows that cold bonded fly ash aggregates can be used as an aggregate replacement material in concrete. The strength property and density of concrete made with artificial fly ash aggregates and natural gravel were also studied which confirms that introduction of fly ash aggregates in concrete reduces the compressive strength but meets the required strength to be used as a structural material.
Fuzzy Risk Analysis Model for Construction Projects
Author(s)- Pejman Rezakhan
ABSTRACT
Compared with many other industries, the construction industry is subject to more risk due to the unique features of construction activities. Risk management aims at identifying sources of risk and uncertainty, determining their impact, and developing appropriate management response. A systematic process of risk management has been divided into risk classification, risk identification, risk analysis and risk response. The ability of a fuzzy system to explain its reasoning process is shown to have definite applicability within the field of risk analysis. Also fuzzy set theory is highly subjective and related to inexact and vague information which we deal in construction projects. This paper describes the development of a fuzzy risk analysis model to assess the risks associated with construction projects. At the end of paper, the proposed model is used to assess the associated risk with a construction operation based on evaluations of three evaluators. The results derived from this model indicate a systematic and effective way for risk analysis.
Investigation of Culvert Settlement in Hyrcanian Forest Roads
Author(s)- Mehran Nasiri
ABSTRACT
Forest engineers and hydrologists regularly calculate design culvert dimensions for use in wildland road-stream crossings. This paper describes a study undertaken to assess the effects of geometric design of forest road and culverts on the rate of culvert settlement of Hyrcanian forest. For this purpose, were measured geometric specification of culvert and proceeded to design cross section using ROADENG software. Results showed increased the rate of settlement with increasing culvert length. So that, was found significant difference among culvert settlements in classes of 0.5 to 0.9 meter and more than 0.9 meter. A significant inverse relationship, with equation of Y = -21.2ln(x) + 19.01 (R² = 0.64) was found between culvert depth and the rate of culvert settlement. The rate of settlement in uphill is more than downhill and the cut and fill slopes has no effect on the rate of settlement. Also, high cross slope of road has an important effect on the rate of culvert settlement. Increased the rate of settlement with increasing culvert skew as compared to 90 degree. So that, there was significant difference between the rate of culvert settlement in classes of 0 to 5 degree and other classes. Thus, inspections should focus on the structural integrity of the road prism, drainage systems, road surface, and sediment control.
Seismic soil-structure interaction of buildings on hill slopes
Author(s)- Pandey A.D, Prabhat Kumar, Sharad Sharma
ABSTRACT
In hilly regions, engineered construction is constrained by local topography resulting in the adoption of either a step-back or step-back-set-back configuration as a structural form for buildings. The adopted form invariably results in a structure which is irregular by virtue of varying column heights leading to torsion and increased shear during seismic ground motion. To capture the real behavior of buildings on hill slope a 3-D analysis of the building is required. In the present study, static pushover analysis and Response spectrum analysis (RSA) have been conducted on five building i.e. three step back buildings and two step back-set back buildings with varying support conditions. These buildings have been analyzed for different soil conditions (hard, medium and soft soils) idealized by equivalent springs. The response parameters, i.e. total base shear (V), displacement from pushover analysis (δ performance point), displacement from RSA (δ elastic) and response correction factor (R’) have been studied with respect to fixed base analysis to compare the effect of soil springs. In general it is found that response reduction factor decreases with increasing time period, but is expected to be constant beyond a certain value of time period.
Experimental study on the behaviour of concrete one way slabs reinforced with GFRP reinforcements under constant and variable amplitude repeated loadings
Author(s)- Sivagamasundari.R, Kumaran.G
ABSTRACT
Non-metallic reinforcements (Glass Fibre Reinforced Polymer reinforcements - GFRP) are viable alternate to the conventional steel reinforcements owing to their excellent properties such as non-corrosive, nonconductive and nonmagnetic properties. This study focuses on the performance of GFRP reinforced concrete one way slabs under constant and variable amplitude fatigue and it is compared with conventionally reinforced concrete one way slabs. A total number of thirty nine one- way concrete slabs, out of which eleven are reinforced with conventional steel reinforcements and twenty eight are reinforced with Glass Fibre Reinforced Polymer (GFRP) reinforcements. Among the thirty nine slabs, sixteen are subjected to static loading, sixteen are subjected to constant amplitude fatigue loading and seven are subjected to variable amplitude fatigue loading. Finite element analysis is also carried out to study the effect of different parameters on the flexural capacity of one way slabs. Different parameters like thickness of slabs, reinforcement ratios, types of reinforcements and grades of concrete are considered. Based on this study, static load carrying capacities and fatigue performance of the conventional and GFRP reinforced concrete one way slabs are compared. A good agreement exists between the analytical and experimental results.
Theoretical study on the behaviour of Rectangular Concrete Beams Reinforced Internally with GFRP Reinforcements under pure torsion
Author(s)- Prabaghar.A, Kumaran.G
ABSTRACT
Finite Element Modelling and analysis of rectangular concrete beams reinforced internally with Glass Fibre Reinforced Polymer (GFRP) reinforcements under pure torsion is carried out in this study. Different parameters like grade of concrete, beam longitudinal reinforcement ratio and transverse stirrups spicing are considered. The basic strength properties of concrete, steel and GFRP reinforcements are determined experimentally. Theoretical torque verses twist relationship is established for various values of torque and twist using elastic, plastic theories of torsion. Finally the ultimate torque is determined using space truss analogy for different parameters considered in this study. Based on this study, a good agreement is made between finite element analysis and the theoretical behaviour.
Modeling and analysis of a three spanned concrete Deck girder bridge under seismic loading
Author(s)- Zasiah Tafheem, Khan Mahmud Amanat
ABSTRACT
This research paper presents the results of a research work aimed at the analysis of a three-span concrete deck girder bridge under seismic loading. A finite element model to analyze the deck girder bridge has been developed by using finite element software ANSYS. This research work has been carried out in two steps. In the first step, a three dimensional model of the bridge has been subjected to equivalent static earthquake loading by following AASHTO code. In the second step, Response Spectrum analysis has been performed. Then the design forces and moments at column bases of the bridge are obtained by using the above two methods. Finally a comparative study of the design values has been performed between those two methods. From the study it has been found that the magnitudes of the axial forces are almost same in two methods but the design moments and shear forces vary significantly. In case of design moment, the result found from response spectrum method (RSM) is about 1.74 times of the design value obtained from equivalent static force method (ESFM). Therefore it can be said that there is a possibility of achieving under design of the bridge if the seismic analysis follows the ESFM. Based on overall findings, it can be suggested that the response spectrum method should be performed for seismic load analysis of the bridge to achieve more reliable and safer design.
