International Journal of Civil and Structural Engineering最新文献

{"title":"Influence of steel slag stabilized mixtures on pavement stress-strain characteristics","authors":"I. Barišić","doi":"10.15224/978-1-63248-057-6-46","DOIUrl":"https://doi.org/10.15224/978-1-63248-057-6-46","url":null,"abstract":"Due to the limitations of empirical methods in pavement structure design, analytical method is applied in order to estimate influence of new materials on pavement stress and strain state. Measured modulus of elasticity for cement stabilized base layer with gravel and steel slag are used for stress and strain calculation using BISAR software. Results show that adding steel slag to cement stabilized mixes with 2% and 4% cement content result in subgrade stress decrease by about 11% and 6% respectively and strain decrease by about 13% and 7% respectively.","PeriodicalId":162063,"journal":{"name":"International Journal of Civil and Structural Engineering","volume":"404 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115920477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shear stress distribution of flat-plate using Finite Element Analysis","authors":"T. Viswanathan, G. Ganesh, A. Santhi","doi":"10.6088/IJCSER.00202030019","DOIUrl":"https://doi.org/10.6088/IJCSER.00202030019","url":null,"abstract":"ABSTRACT The development of a linear numerical model of flat-plate to predict shear stress distribution around slab column connection is presented in this paper. An attempt is made to model the slab, flexural reinforcement and shear reinforcement using three dimensional solid elements. The proposed finite element model has been proved to be capable of simulating the shear behavior of slab-column connection and to be suitable for analysis of structural performance of flat plate structures. Numerical results obtained from this model have good agreement with the available results of other researcher’s numerical model with one dimensional rebar element. Keywords: Flat plate, ABAQUS, shear reinforcement, slab-column connection. 1. Introduction Flat-plate slab system is widely adopted by engineers as it provides many advantages such as reduction of floor height, more spatial planning due to no beams present. These advantages further results in reduction in material cost. In the flat plate slab-column connection is always subjected to combination of high bending moments and shear stresses, which develop a punching, shear failure. This failure is undesirable as it occurs without warning and may lead to progressive collapse of slab. Due to large tensile stresses, the potential diagonal crack in the form of truncated cone or pyramid is formed around the column. The failure surface extends from bottom of the slab at the support, diagonally upward up to the top surface. The angle of inclination with the horizontal depends on slab reinforcement. Hence, designing of flat-plate requires a special attention for both strength and ductility when punching shear being consider. The punching shear capacity of the slab-column connection is affected by the size of the column, the depth of slab, flexural reinforcement and compressive strength of slab etc. The punching shear capacity can be increased by using a larger column diameter, larger effective depth, more flexural reinforcement, higher concrete compressive strength or by shear reinforcement. Among these methods, the most effective way to enhance the slab-column connection is to use shear reinforcement at the punching shear zone (ACI 421 R-99), which is permitted by most of the building codes. The provision of punching shear reinforcement in various forms help in increasing the shear and ductility of the concrete. The various forms of shear reinforcements include stirrups, shear studs, bend up bars, shear heads (placed above the column), etc. According to ACI 318-05, the shear strength is a function of compressive strength of concrete and geometrical condition. The provision given in EC2 also includes the size effect and the effect of the flexural reinforcement ratio. Allowable shear strength of concrete with shear reinforcement is calculated as 0.125 √f","PeriodicalId":162063,"journal":{"name":"International Journal of Civil and Structural Engineering","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116913278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comments on the understanding of the Virtual Work Method","authors":"S. K. Numayr, S. Rjoub","doi":"10.6088/IJCSER.00202030006","DOIUrl":"https://doi.org/10.6088/IJCSER.00202030006","url":null,"abstract":"Students studying elementary structural analysis usually experience some confusion in understanding the concept of virtual work. Most of them think that the work is virtual because it results from a virtual force system, even though the adjective virtual in the term \"virtual work\" describes the work and not the forces. In this paper several comments are given on the concept of virtuality in the virtual work method. The discussion emphasize that the work is virtual rather than the applied unit load or displacement. Excerpts from various text books related to the virtual work method for the calculation of deflections using the unit load method, the derivation of Maxwell's Law of Reciprocal Deflections, and Betti's Law are all discussed. Derivations of these methods are carried out using two different approaches in which no virtual forces are introduced and emphasis is made on the fact that the work is virtual. The term \"assumed loading case\" is proposed to replace “virtual force system”. This paper aims to clarify the concept of virtuality to students learning the method, mainly to prevent the confusion which most students have.","PeriodicalId":162063,"journal":{"name":"International Journal of Civil and Structural Engineering","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129511602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Silica Fume and Metakaolin combination on concrete","authors":"Vikas Srivastava, Rakesh Kumar, V. Agarwal, P. Mehta","doi":"10.6088/IJCSER.00202030017","DOIUrl":"https://doi.org/10.6088/IJCSER.00202030017","url":null,"abstract":"The use of supplementary cementitous materials is fundamental in developing low cost construction materials for use in developing countries. By addition of some pozzolanic materials, the various properties of concrerte viz, workability, durability, strength, resistance to cracks and permeability can be improved. Silica fume is a by product resulting from the reduction of high – purity quartz with coal or coke and wood chips in an electric arc furnace during the production of silicon metal or silicon alloys. Silica fume is known to improve both the mechanical characteristics and durability of concrete. The principle physical effect of silica fume in concrete is that of filler, which because of its fineness can fit into space between cement grains in the same way that sand fills the space between particles of coarse aggregates and cement grains fill the space between sand grains. As for chemical reaction of silica fume, because of high surface area and high content of amorphous silica in silica fume, this highly active pozzolan reacts more quickly than ordinary pozzolans. The use of silica fume in concrete has engineering potential and economic advantage. Metakaolin is also one of such waste/ non - conventional material which can be utilized beneficially in the construction industry. This paper presents the results of an experimental investigations carried out to find the suitability of silica fume and metakaolin combination in production of concrete. The optimum doses of silica fume and metakaolin in combination were found to be 6% and 15% (by weight) respectively, when used as part replacement of ordinary portland cement.","PeriodicalId":162063,"journal":{"name":"International Journal of Civil and Structural Engineering","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129213483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A harmonic vibration, output only and time-frequency representation based method for damage detection in Concrete piers of complex bridges","authors":"H. Ahmadi, F. Daneshjoo","doi":"10.6088/IJCSER.00202030025","DOIUrl":"https://doi.org/10.6088/IJCSER.00202030025","url":null,"abstract":"Due to damage, vibrations of bridge piers compared with undamaged state would be changed. A new signal-based algorithm is proposed to extract feature and detect damage in complex bridges. According to the proposed algorithm, it is necessary to vibrate the bridge before and after damage by exciting force and record responses at the middle and top of the piers. For this purpose, sine and cosine transient forces were applied to the analytical model of Ghotour Bridge and the signals of pier responses were recorded. Using reduced interference distribution, the response signals were processed and time-frequency plans were calculated. Modified matrix subtraction method was proposed to detect damage. Based on the results, damage was identified and located with good accuracy. The proposed algorithm is an output-only method and in practice there is no need to create an analytical model of an existing complex bridge for damage detection.","PeriodicalId":162063,"journal":{"name":"International Journal of Civil and Structural Engineering","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121486569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Damage detection in plate-like structures using High-Order mode shape derivatives","authors":"M. Abdo","doi":"10.6088/IJCSER.00202030009","DOIUrl":"https://doi.org/10.6088/IJCSER.00202030009","url":null,"abstract":"This paper investigates the application and reliability of using high-order mode shape derivatives especially, the fourth derivative in damage detection of plate-like structures. Numerical analyses have been carried out for low- and high-order mode shapes of simply supported and cantilever steel plate models. Six scenarios of damages are studied for plate models to represent different damage characteristics. The influence of artificial noise on the damage identification using changes in fourth derivative of mode shapes has been investigated. Based on the numerical studies, it is shown that the fourth derivative of mode shape is promising in detecting and locating structural damage in plate-like structures since it is localized at the damage locations even for a small amount of damage using only one of the mode shapes. Both low- and high-order mode shapes give successful results. Also, damage indices of the fourth derivatives give smoother localization and consequently better damage identification than those of curvature of mode shapes. Furthermore, using high-order modes (which can be measured by advanced sensors) does not improve the results of damage identification using the fourth derivative. Unfortunately, damage detection using changes in fourth derivative of mode shapes is sensitive to measurement noise.","PeriodicalId":162063,"journal":{"name":"International Journal of Civil and Structural Engineering","volume":"20 23","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113967807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance assessment of low–rise confined masonry structures for Earthquake induced ground motions","authors":"N. Ahmad, Qaisar Ali, M. Ashraf, A. N. Khan, B. Alam","doi":"10.6088/IJCSER.00202030013","DOIUrl":"https://doi.org/10.6088/IJCSER.00202030013","url":null,"abstract":"The performance of low-rise confined masonry (unreinforced masonry walls confined with horizontal and vertical lightly reinforced concrete elements) structures is assessed against earthquake induced site amplified strong ground motions using a probabilistic-based approach. This included analytical investigation of field representative structural models through a suite of natural accelerograms, for various hazard levels. The basic mechanical characteristics of structural material is obtained through experimental investigations recently carried out on masonry material, structural walls and reduced scale structural models, which are employed for the design, mathematical modeling and seismic analysis of confine masonry structures. The seismic performance of two case study (two storey) structure types is assessed for various scenario earthquakes with moderate to strong ground motions. The structures are designed and analyzed considering the existing building stock and new construction recommendations; both differ in provisioning of basic mechanical properties of building material for construction. The typical confinement of masonry walls can avoid the total structural collapse in most of the strong ground motions thereby minimizing the occupant's injuries, however the damages to structures in large earthquake events are significant. Besides the good behavior offered by confinement scheme, the role of construction material's mechanical properties in performance improvement is significant.","PeriodicalId":162063,"journal":{"name":"International Journal of Civil and Structural Engineering","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127043769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plant characteristics, growth and leaf gel yield of Aloe barbadensis milleras affected by cyanopith biofertilizer in pot culture","authors":"Krishnamoorthy","doi":"10.6088/IJCSER.00202030016","DOIUrl":"https://doi.org/10.6088/IJCSER.00202030016","url":null,"abstract":"","PeriodicalId":162063,"journal":{"name":"International Journal of Civil and Structural Engineering","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114558717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of cement kiln dust on Geopolymer composition and its resistance to sulphate attack","authors":"H. Khater","doi":"10.6088/IJCSER.00202030005","DOIUrl":"https://doi.org/10.6088/IJCSER.00202030005","url":null,"abstract":"Utilization of cement kiln dust (CKD) with its high alkali content in the activation of geopolymer specimens to create nonconventional cementitious binders was investigated. Relatively high alkaline content of CKD is predominant factor preventing its recycling in cement manufacture. It was observed that depending on the water-soluble alkalis and sulfate compounds, CKD could provide the necessary environment to activate geopolymer materials. Materials used in this investigation are ground granulated blast furnace slag (GGBFS), air cooled slag (ACS), cement kiln dust (CKD) and calcined kaolin. Calcinations process was done by kaolin firing at 750°C for 3 hours. Alkaline activation by 2% NaOH along with the added cement dust was studied as compared with that not activated by sodium hydroxide. Curing was performed at 38°C under 100% relative humidity. Results showed that 25% CKD is the optimum ratio for geopolymer formation and activation of ggbfs by 2% NaOH along with 25% CKD results in best enhancement in mechanical as well as microstructural characteristics. Activation of low iron metakaolin by 50% CKD and 2% NaOH has the lowest mechanical properties due to calcium deficiency that bind geopolymer matrix. Effect of 5% magnesium sulfate on alkali activated water cooled slag and metakaolin (high iron content) by cement kiln dust results in an enhancement in their mechanical properties up to three months, while subjected to a strength loss up to six months.","PeriodicalId":162063,"journal":{"name":"International Journal of Civil and Structural Engineering","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125016461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution of shear to the columns of short multistorey building frames subjected to lateral loads","authors":"V. Selvam, K. R. Bindhu","doi":"10.6088/IJCSER.00202030001","DOIUrl":"https://doi.org/10.6088/IJCSER.00202030001","url":null,"abstract":"Approximate solutions for multistorey buildings subjected to lateral loads are accepted in lieu of exact analysis by some Engineers. For short building frames in which panel distortion (shear mode) is predominant, the approximate method used is the Improved portal method. This method has been propounded for finding column shears based on a principle widely accepted on its intrinsic merit. However, this maxim has a minor defect, i.e., it gives rise to zero axial forces in the interior columns which is contrary to the actual physical lateral deformation behaviour of the building. In this paper, a new approach is put forward for the determination of shear in columns, which eliminates the flow of the Improved portal method and at the same time yields results close to that of the Improved portal method. The proposed method is scientific as it is founded on a principle depending on the principal flexibility influence co-efficients. It is a valid and useful addition to the Improved portal method.","PeriodicalId":162063,"journal":{"name":"International Journal of Civil and Structural Engineering","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126857692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}