Journal of Materials and Engineering Structures

159-167

Authors: Sachin M. Gunjal, Rajesh B. Hajare, Atteshamuddin S. Sayyad , Manas D. Ghodle

In this paper, a refined trigonometric shear deformation plate theory is applied for the buckling analysis of thick isotropic square and rectangular plates. The theory involves only two unknowns, as against three in first order shear deformation theory and other higher order theories. The theory involves sinusoidal function in the in-plane displacement. The transverse displacement involves bending and shear components. Governing equations and boundary conditions of the theory are obtained using the principle of virtual work. A simply supported isotropic rectangular plate subjected to uniaxial and biaxial compression is considered for the detailed numerical study. Results of critical buckling load for simply supported isotropic rectangular plates are compared with those of other refined theories.

180-205

Authors: Layla A. Gh. Yassin, Eyad K. Sayhood, Qais Abdul Majeed Hasan

This paper represents a historical review, state-of-the-art review, on the experimental researches carried out on corbels in general and strengthening of corbels in particular. The corbels discussed are made of normal, high-strength and self-compacting concrete and subjected to two types of loading, monotonic and repeated loadings. Moreover, a review on the techniques of strengthening used to enhance the load carrying capacities of reinforced concrete corbels is presented too. Finally, directions for future work are proposed and a comprehensive list of references is provided.

213-223

Authors: Nafissatou Savadogo, Adamah Messan, Kinda Hannawi, François Tsobnang, William Prince Agbodjan

In this study, we evaluate the durability characteristics of composite cement with coal bottom ash produced by SONICHAR (Société Nigérienne de Charbon). The study firstly consists in the determination of the pozzolanic activity index of the coal bottom ash and the optimum rate to use in the composite cement. Thereafter an evaluation of capillary absorption, porosity accessible to water and resistance to sulfuric and nitric acid attack of mortar prepared made with the composite cement is performed. The results showed that the coal bottom ash powder obtained by grinding can partially substitute Portland cement at a rate of 15% enable to develop a CEM II A composite cement according to EN 197-1 Standard.

111-119

Authors: Dipali Patel, J. A. Amin

The usefulness of structural walls in the framing of buildings has long been recognized. It is generally preferred to use shear wall in combination with moment resisting frame. In the present study, an effort is also made to investigate the shear wall-RC frame interaction using 2-D modeling of 20, 30 and 35 storey RC frame building with shear wall. In equivalent simplified 2-D model, two exterior frames with shear wall modeled as single frame with double stiffness, strength and weight. The interior frames without shear wall are modeled as a single frame with equivalent stiffness, strength and weight. The modeled frames are connected with rigid link at each floor level. Using 2-D plane frame model the lateral force distribution between Exterior frame with shear wall and Interior frame without shear wall is investigated. From the analysis, it is observed that up to bottom seven/eight storey more than 50% load is taken by frame with shear wall and the lower most three storeys take about 75% of total storey shear.

130-144

Authors: Berrabah Hamza Madjid, Adda Bedia El Abbas, Fahsi Bouazza

In the first part of this work, analytical expressions were determined for the stresses through the thickness of a composite beam submitted to electrical excitation. In the second part of this study we are interested in the theory of elasticity, which is used to obtain exact solutions of piezo-thermo-elastic consoles gradually coupled evaluated under different loads. These solutions are used to identify the piezoelectric parameter and thermal coefficients of the materials. In addition, numerical results are obtained for the analysis of the loaded console by two different types of loading. In this study we show also that changing the linear thermal parameters of the material does not affect the distribution of the stress and the induction of the beam. However it affetcs the components of the deformation, electric field, the displacement and the electric potential of the console.

57-67

Authors: Taghreed Kh. Mohammad Ali, Maha M. S. Ridha, Zinah Asaad, Layla A. Gh.Yaseen

In this paper, the axial behaviors of reactive powder concrete (RPC) short columns confined with carbon fiber reinforced polymer (CFRP) were investigated. All the specimens have square cross section of 100 mm × 100 mm and length of 400 mm with aspect ratio 4. The experimental work consists of three groups. The first group consists of six specimens of RPC with 2% micro steel fiber, without ordinary reinforcing steel and confining by zero, one and two layer of CFRP respectively. The second group consists of six specimens of RPC with 2% micro steel fiber and minimum ordinary reinforcing steel and confining by zero, one and two layers of CFRP respectively. The third group consists of four specimens of RPC without micro steel fiber and ordinary reinforcing steel and confining by one and two layers of CFRP respectively. Experimental data for strength, longitudinal and lateral displacement and failure mode were obtained for each test. The toughness (area under the curve) for each test was obtained by using numerical integration. The RPC columns confined with CFRP showed stiffer behavior compared with RPC columns without CFRP. The ultimate load of the RPC columns with 2% micro steel fiber + two layers of CFRP + minimum ordinary reinforcement were more than that of the RPC columns with 2% micro steel fiber + minimum ordinary reinforcement and without CFRP by about 1.333.

77-89

Authors: S. Arora, S. P. Singh

The paper presents results of an investigation to study the flexural fatigue performance of concrete beams made with 100% Coarse Recycled Concrete Aggregates (RCA). Experimental investigation has been carried out to obtain the flexural fatigue lives of concrete beam specimens of size 100 × 100 × 500 mm at various stress levels under four points flexural fatigue loading. The test data is used to plot the S-N curves and a simple regression analysis is used to propose an equation to estimate the flexural fatigue strength of concrete made with 100% RCA. The flexural fatigue performance of concrete made with 100% RCA has been assessed in terms of its mean and design fatigue lives. Two million cycles fatigue strength/endurance limit has also been estimated and compared with the previous studies available on Coarse Natural Aggregates (NA).

99-110

Authors: Vladimir Sedlak

On the present in accretive exigencies to people and its property protection, there is security one from priority needs and tasks of all countries or their groupings around the world. In the environment protection, which an unspoiled ecosystem is a condition of human living, it is needed to protect people and its property against the negative industrial influences. The mining activity influence on the environment belongs to the most negative industrial influences. As a result of underground mining of the mineral deposits in the surface creates the subsidence trough, i.e. caving zone (area) which could be dangerous for any movement of people in this zone. Character and size of the subsidence on the surface depends mainly on the geotectonic ratios of rock massif above the mined out area. Knowing the extent of the subsidence trough in mining areas is determining to prevent the entry of people into these dangerous zones. Conditioning factors to establish the extent of the movement of the earth's surface above the mined out area are a geodetic way surveyed deformation vectors which can be derived from the processing of measurements at monitoring stations based on these mining tangent territories. 3D (three-dimensional) deformation vectors most adequately characterize movements of ground, buildings and other engineering structures above the mined out area. The article gives the specific case of the deformation vectors solutions in a case of disruption of the geodetic network structure at a monitoring station during periodical measurements. The theory of this specific solution of the deformation vectors was developed for the mining area near the city of Kosice in Slovakia. Some numerical and graphical results from the deformation vectors estimation in the magnesite deposit Kosice-Bankov are presented. The obtained results are transferred into GIS (Geographical Information Systems) for the needs of local governments.

3-15

Authors: Bharti M. Shinde, Atteshamuddin S. Sayyad, Shantaram M. Ghumare

In this paper, a refined trigonometric shear deformation theory is applied for the bending analysis of isotropic and orthotropic plates under the various loading conditions. The two unknown variables are involved in the present theory. The present theory satisfies the shear stress free condition at top and bottom surface of the plates without using shear correction factors. The governing equations and boundary conditions are obtained by using the principle of virtual work. A closed form solution is obtained using Navier Solution Scheme. A simply supported isotropic and orthotropic plate subjected to sinusoidally distributed, uniformly distributed and linearly varying loads are considered for the detailed numerical study. The results obtained using present theory are compared with previously published results.

26-32

Authors: Ajay Kumar Agarwal, Vaishali Rajurkar, Prerna Mokadam

Expansive soils such as black cotton soil which are widely distributed in India have a tendency for volume changes due to change in moisture content. Also exhibits very low bearing capacity and high compressibility. Stabilization of such soil by admixture is used commonly now days. But no mix is suitable to improve all the types of soil. But it is obvious that depending on type of soil & type of admixture the optimum mix can be designed. In this paper a mix has been designed to improve the bearing capacity of soil by using fly ash and lime mixture, reinforced with waste synthetic bag pieces. Various tests are carried out to determine the CBR value and other soil properties with and without using any admixture and reinforcement. The maximum value of CBR was found to be23.82% for 2.5 mm penetration and 22.21% for 5 mm penetration, when waste synthetic bag pieces of size 2 cm * 2 cm were used at a proportion of 0.1%.

44-55

Authors: Ruchi Sharma, Jignesh A. Amin

Tall towers and multi-storey buildings have fascinated mankind from the beginning of civilization, their construction being initially for defense and subsequently for ecclesiastical purposes. These tall buildings because of its height, is affected by lateral forces due to wind or earthquake actions tends to snap the building in shear and push it over in bending. In general, the rigidity (i.e. Resistance to lateral deflection) and stability (i.e. Resistance to overturning moments) requirement become more important. Shear walls (Structural walls) contribute significant lateral stiffness, strength, and overall ductility and energy dissipation capacity. In many structural walls a regular pattern of openings has to be provided due to various functional requirements such as to accommodate doors, windows and service ducts. Such type of openings reduces the stiffness of the shear wall to some extent depending on the shape and size of the opening. In the present parametric study, efforts are made to investigate and critically assess the effects of various size of openings in shear walls on the responses and behaviors of multi-storey buildings. The 30 storey Prototype buildings with different types of openings in shear wall with and without incorporating the volume of shear wall reduced in the boundary elements are analyzed using software E-TABS using Response spectrum method (1893(Part-1)-2002) and Time history method.

119-126

Authors: Abdelmonem Masmoudi, Mongi Benouezdou, Mohamed Beldi, André Weber

GFRP composite bars are excellent alternative to steel bars for reinforcing concrete structures in severe environments. However, studies on creep phenomenon of GFRP reinforced concrete structures are limited. Creep occurs as a result of long term exposure to high levels of stress that are below the yield strength of the material. This paper (Part A) presents a literature review and the loading history of six experimental beams reinforced with GFRP and steel bars. The results of this study revealed that Beams reinforced with GFRP are less marked with creep phenomenon. This investigation should guide the civil engineer/designer for a better understanding creep phenomenon in GFRP reinforced concrete members.

137-145

Authors: BOUAZZA MOKHTAR, Abedlouahed Tounsi, EL Abbas Adda-Bedia

In this paper, the buckling of a functionally graded plate is studied by using first order shear deformation theory (FSDT). The material properties of the plate are assumed to be graded continuously in the direction of thickness. The variation of the material properties follows a simple power-law distribution in terms of the volume fractions of constituents. The von Karman strains are used to construct the equilibrium equations of the plates subjected to two types of thermal loading, linear temperature rise and gradient through the thickness are considered. The governing equations are reduced to linear differential equation with boundary conditions yielding a simple solution procedure. In addition, the effects of temperature field, volume fraction distributions, and system geometric parameters are investigated. The results are compared with the results of the no shear deformation theory (classic plate theory, CPT).

155-168

Authors: hocine bendadouche, kaddour khemmoudj, smail merabet

This article has the results of the cyclic triaxial compression tests to study the potential of liquefaction of a gravel-sand material. The last part is devoted to the not drained cyclic tests and their analyses. Many articles are devoted to the tests on the standard sand of laboratory Hostun in particular for the study of liquefaction or on reconstituted clays but few tests are carried out on a natural material. The scarcity of cyclic tests on such rough natural materials shows the difficulty of assessing the seismic risk. Faced with these difficulties, the use of tests such as the CPT provides a different but very practical approach. The overall results show a trend of relatively high liquefaction of the material, even under conditions of moderate stress (qc / 2s'3 = 0.2). This trend is growing very strongly when the rate of cyclic loading reached 0.3. The CPT test also shows a great tendency to liquefaction with a safety factor of well below 1.