فهرست مطالب

Asian journal of civil engineering - Volume:18 Issue:1, 2016
  • Volume:18 Issue:1, 2016
  • تاریخ انتشار: 1395/07/19
  • تعداد عناوین: 9
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  • M. Mouffok*, N. Zemmouri, L. Aidaoui, Y. Lasbet, A. De Herde Page 1
    The present work investigates the CO2 dispersion in micro-scale urban area, and its effects on air quality in old buildings in the city of Ghardaïa (M’Zab valley). The city of interest is located in the south of Algeria. Ghardaïa is characterized by its vernacular urban structure well adapted to local climate (hot arid) which is listed by the United Nations Educational, Scientific and Cultural Organization (UNESCO) as a protected city. Numerical simulation with CFD code was used in combination with measurement data in order to study the CO2 air pollution levels in the selected area. The field measurements carried out for the two days: 5th and 6th July 2013, shows that CO2 concentration in the street canyon reaches its highest level up to 400 ppm. Two numerical simulations were performed based on geometry changes and architectural propositions on the downstream buildings, to assess the effects of morphology on the CO2 air pollution dispersion. The first improvement was made by increasing the street canyon width at the outlet side, which reduced the CO2 concentration by 46%. In the second modification, which was made by changing the uneven building layout, this improvement decreased the CO2 concentration by 36% compared to the real geometry. The results show the effect of weak modifications of the architectural fabric on the air pollution reduction, and therefore the participation in protecting old buildings heritage from air pollution effects.
    Keywords: Old heritage, urban morphology, architectural propositions, CO2 air pollution, Ghardaïa
  • T.M. Jeyashree*, G. Chitra Page 21
    Concrete is the essential construction material used for many applications in the construction industry. Though it is used worldwide, it has its ill effects like the presence of pores and micro-cracks. These ill effects lead to acid intrusion and less resistance to atmospheric attack. As a result, its durability and strength get reduced. In this study attempt was made to investigate the effect of waste carbon black powder addition as filler material in concrete. Study on uniformity, surface hardness, split tensile strength, flexural strength and compressive strength of concrete specimens containing various percentages of carbon black were carried out. The effectiveness of using waste carbon black as filler in cylinders with rebar was also studied. From the experimental results, it can be seen that optimum percentage of 5% to 8% carbon black can be effectively used for enhancement of properties of concrete.
    Keywords: Carbon black, filler, hardness, uniformity
  • A. Sumathi*, M. Chandra Babu Page 31
    This paper presents a study on behavior of cold formed steel (CFS) beam with plain web, triangular corrugated web and trapezoidal corrugated web. This study involves in examination of theoretical and experimental investigations of specimens in series. Overall three specimens were tested with length of 1200 mm. All specimens are tested under two point loading with simply supported condition. The theoretical data are calculated using Indian Standard code IS 801-1975. The load carrying capacity and failure modes of beams were discussed. Based on the test beam with trapezoidal corrugated web shows maximum load carrying capacity compared with the plain web.
    Keywords: Cold formed steel, load deflective curve, stiffness, failure modes
  • S.G. Patel*, G.R. Vesmawala Page 39
    Increasing of traffic intensity due to technology advancement in heavy axle vehicles affects overall integrity of highway bridges. Along with the traffic intensity, aging of structural elements leads to distress of structure. Due to distressing in structural elements, stiffness gets reduced. Research studies based on vibration test methodology shows that change in fundamental frequency of any structures is directly related to overall stiffness of the structure. Therefore, many research studies have been carried out across the globe by researchers in the field of vibration based monitoring of the structure to identify dynamic behaviour by using properties such as natural frequencies, mode shapes and modal damping ratios. In this paper, ambient vibration test on a bridge where measurements taken with instrumentation of acceleration sensors on the bridge span. For the study, concrete I girder bridge on the ring road over Sabarmati River near Ahmedabad City is selected. The bridge is characterized by a system of post-tensioned I girder simply supported beams with span. The dynamic characteristics of the bridge were computed by using Stochastic subspace identification (SSI) method and Least squares complex frequency domain (LSCF) Method, which is further used to study fundamental frequency of bridge.
    Keywords: Ambient vibration test, operational modal analysis, stochastic subspace identification, least squares complex frequency domain bridge
  • J. Revathy*, R. Sudha Page 49
    Corrosion of steel reinforcement in concrete is considered to be the major cause of deterioration in civil infrastructure facilities. The use of fibre-reinforced polymer (FRP) tubes acts as a structurally integrated stay-in-place form for concrete members that expand the service life of structures, enhancing the corrosion resistance and potentially high durability. This paper presents on an experimental study on the structural performance of normal and high strength of concrete infilled FRP thin walled tubular beams with different configurations. The concrete filled FRP thin walled tubular beams showed an increase in ultimate load carrying capacity, stiffness and ductility.
    Keywords: FRP tubular beams, HSC, NSC, thin walled, woven roving, unidirectional cloth
  • S.M. Dumne*, M.K. Shrimali, S.D. Bharti Page 63
    This study proposed two hybrid controls for response mitigation of adjacent buildings connected by dampers referred as coupled building of which base of taller building being isolated. These controls developed using Magnetorheological dampers in combination with Friction Pendulum System and Resilient Friction Base Isolator respectively named as, Hybrid control 1 and Hybrid control 2. Most effective hybrid control is investigated by comparing the responses obtained by hybrid controls with the responses of same coupled building with Semi-active control. Further, influence of device parameters on performance of hybrid control has been studied through parametric study. The result shows that Hybrid controls are more effective in reducing the responses compared to Semi-active control, however Hybrid control 2 perform more effective not only in response reduction but also in pounding effect.
    Keywords: Hybrid control, Semi, active control, coupled building, MR damper, sliding base isolation, pounding, device parameters
  • H. Nourmohammadzad, H. Alizadeh, F. Kheirabadi* Page 99
    The heat of the earth is provided by sunshine radiation. A change in the angle of sunshine radiation and the surface of Earth, the height and distance of the Sun from the Earth causes changes in ambient temperature. Sometimes these changes will reduce climatic comfort for human beings. Climatic comfort is established when there is a balance between excreted and absorbed temperature by the skin of the body. Orientation of the physic of the squares to geographic north causes changes in the received amount of direct sunshine radiation in different months. Thus the establishment is appropriate in some orientations and inappropriate in others. The inappropriate orientation of the physic in most squares of the city of Yazd reduces the climatic comfort of the citizens. In this study, the correlation coefficient was used and the difference between the different orientations regarding the amount of getting sunshine radiation was calculated using the software R. Calculations were based on a fixed rectangle in the eight cardinal and intercardinal orientations during the year and have been compared with each other in terms of climatic comfort. According to the results, north-south orientation is the most desirable orientation in the whole year for the physic of squares in Yazd. Getting close to the east-west orientation reduces the desirability. The difference in getting sunshine radiation between the orientations is quite significant. This study shows that using the north-south orientation or orientations near it for the physic of squares in Yazd, increases climatic comfort of the citizens.
    Keywords: Orientation of the physic of squares, climatic comfort, shading of the physic, warm, dry climate
  • R. Ramasubramani*, S. Divya, K.S. Satyanarayanan Page 119
    In the process of engineering design and construction, the concrete cover thickness is very critical. If the concrete cover thickness does not reach to design specifications and drawing requirements, it will be easy to cause some defects, such as surface cracks on building components and even reduce the structure strength and durability etc. In this paper, strength criteria is consider with three specimens with gradual removal of clear cover thickness (50-25-0 mm) of different grade of concrete to investigate the flexure behavior of over reinforced concrete beam. The results of laboratory investigation on removal clear concrete are present. Data presented includes load v/s deflection characteristics, crack width and stiffness when tested on 28 days.
    Keywords: Cover concrete, clear cover, flexure
  • S. Muthu Kumar*, J. Joson Western, K.S. Satyanarayanan Page 133
    The reinforced concrete (RC) moment-resisting frames with masonry infill walls is widely used in buildings. In this study, two-bay and three-storey RC Bare Frame (BF), RC Infill frame (IF) with Cement mortar (CM) interface combinations scaled to a factor (1:6) are analyzed. The objective is achieved by analytical studies. To investigate this, we modelled the behavior of frame structures with masonry IF in two ways such as a linear method and Pushover (PO) method. It is found that with the addition of masonry infill wall rigidly connected to the frame, the lateral strength, the stiffness of the BF RC frame increase significantly while the displacement ductility ratio decreases significantly. Numerical simulation of the BF and the IF frames is done with SAP2000 (Structural Analysis Package) a Finite Element Method (FEM) based software.
    Keywords: Bare frame, infill frame, interface, linear, nonlinear, lateral stiffness