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Seismic Analysis (Non-linear Static Analysis (Pushover) and Nonlinear Dynamic) on Cable - Stayed Bridge
Mohammad Taghipour,
Hesamoldin Yazdi
Issue:
Volume 3, Issue 5, September 2015
Pages:
129-139
Received:
12 August 2015
Accepted:
25 August 2015
Published:
5 September 2015
Abstract: Pushover analysis application development is greatly increased in recent years and numerous advanced methods to evaluate the seismic pushover are provided. Because these methods have been proposed mainly for building structures and given the fundamental differences between the behavior of bridge structures and buildings using pushover methods on the bridge structure with the uncertainties faced. 1. First, the effect of non-linear pushover results (time history) 2. Choose a target displacement due to the finite element model should be examined in order to understand the prediction of the seismic capacity. Thus a pushover analysis is presented for evaluation of seismic bridge pylons and deck where the effects of displacement and deformation of the plastic joints, structural changes in the modal characteristics of change used plastic forms and effects of higher modes can be seen clearly. The method is able to accurately approximate the dynamic response of the nonlinear analysis. Ultimately this method compared with analysis time history.
Abstract: Pushover analysis application development is greatly increased in recent years and numerous advanced methods to evaluate the seismic pushover are provided. Because these methods have been proposed mainly for building structures and given the fundamental differences between the behavior of bridge structures and buildings using pushover methods on th...
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Thermo-Physical Properties of Local Materials Used in the Construction of Chad
Ahmat-Charfadine Mahamat,
Mahamat Barka,
Abakar Mahamat Tahir,
Malloum Soultan,
Salif Gaye,
Aboubakar Cheikh Beye
Issue:
Volume 3, Issue 5, September 2015
Pages:
140-149
Received:
22 August 2015
Accepted:
8 September 2015
Published:
24 September 2015
Abstract: As earth is the most commonly used construction material in Chad, the purpose of the present study is to characterize it as a whole, and to characterize its thermo physical properties. Various tests were conducted on it and mainly on its thermo-physical characteristics, as these significantly affect the comfort of a house. The study focused on earth taken from a climate zone of Chad, mixed with straw at a given proportion or used alone. Different values of thermal conductivity and diffusivity of these materials as well as their variations in relation with water continence are presented.
Abstract: As earth is the most commonly used construction material in Chad, the purpose of the present study is to characterize it as a whole, and to characterize its thermo physical properties. Various tests were conducted on it and mainly on its thermo-physical characteristics, as these significantly affect the comfort of a house. The study focused on eart...
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A Macroscopic Fundamental Diagram for Spatial Analysis of Traffic Flow: A Case Study of Nyeri Town, Kenya
Lekariap Edwin Mararo,
Abiero Gariy,
Mwatelah Josphat
Issue:
Volume 3, Issue 5, September 2015
Pages:
150-156
Received:
1 September 2015
Accepted:
21 September 2015
Published:
22 October 2015
Abstract: Traffic flow analysis is an essential component of a town’s traffic and transport systems since these flows could, and often do lead to the occurrence of congestion on our roads.Traffic congestion is a growing problem in Nyeri, Kenya, resulting from rapidly increasing population and the crowding of motorized traffic onto a limited street network. This research performed spatial analysis of traffic flows on some road links in Nyeri town. On those selected road links it also established fundamental traffic flow models and derived the flow characteristics associated with traffic operations in Nyeri town, determined the characteristics of a Macroscopic Fundamental Diagram (MFD) for Nyeri town and assessed to determine whether it is a property of the network infrastructure and control or of the travel demand. In this research, MetroCount Vehicle Classifier was used to collect traffic intensity and velocity data at different locations of the network over certain durations and at the same period between January 2015 and February 2015. The analysis of the data was performed by the MetroCount Traffic Executive MCReport. The MFD resulting from the study served as a road network performance indicator, which tells the performance levels of the town in general, in terms of traffic flow. The research was used to determine the capacity of the road network and the level of congestion in different links thereby determining the adequacy of the network. The speeds in Nyeri town are moderate, however, low and high speeds occur occasionally and the volumes of traffic in Nyeri town are not high hence congestions are rarely experienced. The results of this research study are anticipated to better traffic management, and also improve mobility and accessibility in Nyeri town.
Abstract: Traffic flow analysis is an essential component of a town’s traffic and transport systems since these flows could, and often do lead to the occurrence of congestion on our roads.Traffic congestion is a growing problem in Nyeri, Kenya, resulting from rapidly increasing population and the crowding of motorized traffic onto a limited street network. T...
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Composite Concrete Slabs with Profiled Steel Decking: Comparison Between Experimental and Simulation Study
Namdeo Hedaoo,
Namdeo Raut,
Laxmikant Gupta
Issue:
Volume 3, Issue 5, September 2015
Pages:
157-169
Received:
23 September 2015
Accepted:
4 October 2015
Published:
5 October 2015
Abstract: The research work is to study the behavior of the composite concrete slabs with CRIL DECKSPAN type profiled steel decking by experimental and simulation study. The slab is created by composite interaction between concrete and steel deck with rolled embossments to improve their shear-bond characteristics. However, it fails under longitudinal shear-bond due to the complex phenomenon of shear behavior. Therefore, an experimental full-size tests has been carried out to investigate the shear-bond strength under flexural test in accordance with Eurocode 4: Part 1.1. Eighteen specimens are split into six sets of three specimens each in which all sets are tested for different shear span lengths under static and cyclic loading on simply supported slabs. The full-size finite element (FE) modeling and analysis of the composite slabs is presented, in which the shear-bond interaction between the concreteand steel deck is simulated by the use of interface contact elements. The FE analysis is verified and validated by comparing the experimental results. Comparisons of the experimental and simulation results indicate that the FE analysis agrees well with the test results, and is capable of predicting the behavior and the load carrying capacity of composite slabs.
Abstract: The research work is to study the behavior of the composite concrete slabs with CRIL DECKSPAN type profiled steel decking by experimental and simulation study. The slab is created by composite interaction between concrete and steel deck with rolled embossments to improve their shear-bond characteristics. However, it fails under longitudinal shear-b...
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Identification and Management of Risks in Construction Projects
Mohammad Ali Rezvani Befrouei,
Mohammad Taghipour
Issue:
Volume 3, Issue 5, September 2015
Pages:
170-177
Received:
25 September 2015
Accepted:
4 October 2015
Published:
30 October 2015
Abstract: Today, risk management in construction projects is considered to be a very important managerial process for achievement of project’s objectives in terms of time, costs, quality, safety, and environmental sustainability. Instead of employing a systematic approach for identification of risks, their probability and their effects, most of the studies conducted in this area have focused only on a few aspects of risk management in construction project. However, the present study aims to identify and analyze the risks associated with development of construction in the greater city of Tehran, employing a comprehensive approach that is consisted of five aspects. In order to conduct this descriptive-analytical research, after studying, identification and categorization of different types of risks and preparing a relevant questionnaire, a number of 52 active construction companies from different areas have been randomly selected to be questioned about the impact of those risks on construction projects. After the collection and observation of the data, the output was examined by Pearson correlation also, using charts and tables. The results indicated that “tight project schedule” – present in all five categories- imposed the maximum risk. Also “design variations”, “excessive approval procedures in administrative government departments” and “unsuitable construction program planning” were identified as next high risk factors.
Abstract: Today, risk management in construction projects is considered to be a very important managerial process for achievement of project’s objectives in terms of time, costs, quality, safety, and environmental sustainability. Instead of employing a systematic approach for identification of risks, their probability and their effects, most of the studies c...
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Effects of Crude Oil Contaminant on the Engineering Properties of Concrete
George Abednego,
Onungwe Ishmael,
Oba Achemie,
Akpan Paul,
Sarogoro Samuel
Issue:
Volume 3, Issue 5, September 2015
Pages:
178-182
Received:
15 October 2015
Accepted:
26 October 2015
Published:
16 November 2015
Abstract: The artificial application of crude oil in various percentages in concrete mix constituent to under study the service interaction of concrete in contact with oil was carried out. The research contained herein present the investigation, analysis and comparative results obtained from a total of 96 concrete cubes sample consisting of 12 control cubes, 12 0% contaminated cubes cured in Bodo crude oil water and 72various percentages of crude oil contaminated cubes cured in potable water. The tests conducted were slump and flow rate in terms of freshly mixed concrete and compressive strength in terms of hardened content. The OPC concrete mix which adopted 0.5 water cement ratio was cured for 7, 14, 21 and 28 days in its cubes form and the results obtained indicated that concrete is highly susceptible when in contact with crude oil. Its contact with crude oil causes it to deterioration as well as slow strength development and increased percentage flow rate. The difference between the control mix and the 25% crude oil contamination was 16N/mm2 at 28 days, which explicitly spells out the consequences of crude oil effect on the properties of concrete structures.
Abstract: The artificial application of crude oil in various percentages in concrete mix constituent to under study the service interaction of concrete in contact with oil was carried out. The research contained herein present the investigation, analysis and comparative results obtained from a total of 96 concrete cubes sample consisting of 12 control cubes,...
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Influence on the Performances of Foamed Concrete by Silica Aerogels
Cheng Hai-li,
Yang Fei-hua,
Wang Yi,
Hao Li-wei
Issue:
Volume 3, Issue 5, September 2015
Pages:
183-188
Received:
2 December 2015
Published:
3 December 2015
Abstract: Aiming at the problems of organic thermal insulation material, SiO2 aerogel was mixed into foamed concrete in two different ways, to investigate its effects on thermal conductivity, compression strength and volume water absorption of foamed concrete. XRD, FT-IR and SEM have also been used to analyze the relationship between both the amount and the mixing way of aerogel and macro properties of foamed concrete. The results show that directly mixing aerogel into foamed concrete has limited effects on improving its performace, mixing 0.5% of aerogal has little effect on improving thermal conductivity, while mixing 2.5% of aerogel can greatly decrease compression strength though thermal conductivity has been improved. If aerogal has been premixed with glycol and hydroxypropyl methyl cellulose(HPMC) ether and then mixed into foamed concrete, the compression strength will decrease less while thermal conductivity could decrease by 35%, volume water absorption by 31%.
Abstract: Aiming at the problems of organic thermal insulation material, SiO2 aerogel was mixed into foamed concrete in two different ways, to investigate its effects on thermal conductivity, compression strength and volume water absorption of foamed concrete. XRD, FT-IR and SEM have also been used to analyze the relationship between both the amount and the ...
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Study on Roller Compacted Concrete’s Nominal Fracture Toughness Based on Crack-Depth Ratio
Issue:
Volume 3, Issue 5, September 2015
Pages:
189-193
Received:
5 December 2015
Published:
5 December 2015
Abstract: The roller compacted concrete (RCC) has been widely used, and the practical concrete crack usually has different crack-depth ratios, but the researches about the fracture toughness formula for RCC rarely consider crack-depth ratio. Here the wedge-splitting fracture test was carried on the RCC specimens with different crack-depth ratios(0.4, 0.5, 0.6). At the same time, the theoretical nominal fracture toughness formula based on the crack-depth ratio was also studied. At the end, the modified and suitable RCC' formula based on crack-depth ratio was gotten by combining the RCC test results with theoretical formula.
Abstract: The roller compacted concrete (RCC) has been widely used, and the practical concrete crack usually has different crack-depth ratios, but the researches about the fracture toughness formula for RCC rarely consider crack-depth ratio. Here the wedge-splitting fracture test was carried on the RCC specimens with different crack-depth ratios(0.4, 0.5, 0....
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