Articles in This Issue
Abstract
The concept of the modern maintenance management has been developed inparallel with the international development of the science and technology, especiallytargets identification of the management, and it’s duties in the hydraulicestablishments.The research included a real state study of maintenance management activitiesof Himreen dam to propose a suitable maintenance management system. Also itpresented a description of the dam importance and discussed the concept of themodern maintenance; definition, classification, and the analysis of the four factors ofmanagement system which are (planning, organizing, directing and controlling).The field survey included preparing the questionnaire list, conducting thestatistical analysis for it's axes, and discussing the results.Many conclusions and recommendations have been deduced which related tothe applications of the maintenance management in the dam project, and to generalizethe proposed system in future to all dam’s projects in Iraq.
Abstract
This research includes the study of improving impact resistance of concrete using styrene butadiene rubber (SBR) with different weight ratios of polymer to cement 3%, 5% and 10%. Two series of polymer modified concrete (PMC) were produced the first level I with moderate compressive strength and the other level II with higher compressive strength. Cubes, prisms and panels were made as follows: Results showed an improvement in impact resistance of polymer modified concrete (PMC) over reference concrete in low-velocity and high-velocity impact properties. In conducting low-velocity impact tests, method of repeated falling mass was used: 1300gm steel ball falling freely from three heights 2400mm, 1200mm and 830mm. In high-velocity impact tests, shooting of 7.62mm bullets was applied to slab specimens from distance of 15m. The improvements were significant in low velocity impact resistance. The maximum increases were (33.33%, 75% and 83.33%) at ultimate failure for falling mass heights 2400mm, 1200mm and 830mm respectively. In high-velocity impact strength tests, maximum reductions recorded in spalling area were (18.5% and 27%) for polymer modified concrete (level I) with moderate compressive strength and polymer modified concrete (level II) with higher compressive strength.Maximum reductions recorded in scabbing area were (11.42% and 35.6%) for polymer modified concrete (level I) with moderate compressive strength and polymer modified concrete (level II) with higher compressive strength, respectively.
Abstract
Ramadi city is one of the cities, which needs to a comprehensive transportation studies because of the change in the economic and social state of the population. This change cause an increasing in the number of population and the proportion of owns the vehicle, thus increasing the number of trips, thereby making them suffer jamming in the transportation network at peak hours. For purposes of this study, the city were divided into 18 zones in which data has been collected for special statement makers trips (the rate of income, vehicle ownership,...... etc.), the purpose of the trip, and the characteristics of transportation modes (the time of trip, the cost of the trip ,.... ... etc). A model was building for the purpose of the trip (shopping trip, working trip, and education trip) to predict the percent of contribution of each type of transportation modes for trips attraction to the city, by finding of the relationship between them and the characteristics of trip ,trip-makers and transportation modes. a strong linear equations where found after analysis by multi-linear regression and these equations can be used in the future forecasting for the city.
Abstract
During the last four decades, incidence of failure of reinforced concrete structures has been seen widely for many reasons, such as increasing service loads ,war accidents, fire and/or durability problems and the economic losses due to such failures are costly. Nowadays, the size and the form of repair and rehabilitation market are too large since there has been an increased emphasis on repair and retrofitting of defected structures over demolition and new construction. An expert system is an interactive computer-based decision tool that uses both facts and heuristics to solve difficult decision problems based on knowledge acquired from an expert. To realize these requirements, a logic programming Prolog language was utilized together with diagnosis technology. The logic programming language formalizes the domain knowledge. The expert system Diagnosis of Fire Simple R.C Building Members Damages (DFSRCMD) developed in this paper is a diagnostic advisory system, which can be used as an alternative to the human expert, to give technical decisions in diagnosing fire damages in R.C. structural elements: beams, columns and slabs.
Abstract
In this study remote sensing was employed with Geographical Information System (GIS) for study the hydrochemistry properties for Habania Lake that is located on Euphrates river, where the use of traditional methods are not fulfill the demands for study quality and situation of water of great areas which need enough time and money . Analytic study was performed on hydrochemical aspect through samples of store water and make physical and chemical water tests with GIS to product layers represent place distribution nature of these elements on the whole area of reservoir through the use of satellite image. The present study concluded that the use of remote sensing , geographic information system and analytic study for samples was employed to study quality and situation of water .
Abstract
Traffic control devices notify road users of regulations and provide warning and guidance needed for safe, uniform, and efficient operation of all elements of the traffic stream. Traffic control devices have been a part of the roadway system. Researches have evaluated various aspects of the design, operation, placement, and maintenance of traffic control devices. The purpose of this research is to develop a simulation model in order to evaluate the effect of overhead sign position on the traffic performance at exit of freeway weaving area. To achieve that subroutine was developed and added to FWASIM program to compute the sign position and compare it with the driver sight distance. Following that a proposed example represents an exit weaving area was examined with different traffic flow configuration (different percentages of link flow and on-ramp flow) with respect to no sign installed and other three sign positions. Results indicate that the average traffic speed is underestimated when there is no sign installed, while no significant effect is shown when the sign position is changed within the driver sight distance. In conclusion Guide signing is a critical element in the effective, efficient and safe operation of motorways and expressways. Signing issues must, therefore, be fully considered at the feasibility stage of any project.
Abstract
Traffic engineers frequently are engaged in evaluating the performance of different facilities of the highway system. The facility in this project includes freeway section. In design of a freeway, a forecast demand volume is used with known design standards for geometric features and a desired level of service to compute the number of lanes required for the freeway section in question. The design application is straight forward for each usage, but trial-and- error operation analysis may be required to evaluate alternative design. Design requires a detailed traffic forecast, including volumes, peaking characteristics, traffic composition, and specifics of vertical and horizontal alignment for the section under study. The aim of this paper is the design analysis of a freeway with a heavy recreational vehicles. This analysis involves the consideration of three examples of freeways. Given known geometric roadway conditions and projected traffic conditions , the design analysis yields an estimation of the number of lanes and of the speed and density of the traffic stream. This paper has described the procedure for determining the number of lanes of freeway basic sections as presented in the Highway Capacity Manual (HCM, 2000) and HCS2000 software.
Abstract
This study is the second stage of the paper “Study the Effect of Rubber Silicon on Physical Properties of Asphalt Cement”. This study took the effect of additives on asphalt mixture performance. Asphalt mixture has been designed by Marshall method for determining the optimum asphalt content and geophysics properties of mix according to ASTM (D- 1559 ). Rubber silicon at different percentage (1%, 2%, 3% and 5%) was added to asphalt binder and three specimens of asphalt rubber silicon mixture (ARSM) are prepared and evaluating according to Marshall method. Diametric tensile creep test ASTM (D-1075) at 60 Co used to evaluating permanent deformation and modulus of elasticity for ARSM. The study shown that the Rubber-Silicon has more effects increasing the marshal stability, air voids, and reducing the flow and bulk density compared with the original mix.. Increase the flexibility properties of the mix and this appear from reducing the permeate deformation at test temperature (60C), the reduction percent is about (30 to 70)%
Abstract
The geometric design of highway alignment consists mainly of the design of horizontal alignment and Vertical alignment. The more important step in horizontal alignment design is the curve radius determination. The equation used for horizontal curve radius determination is developed with assumption that when vehicle run on curved section, there are an acting force on it. This force include the centrifugal force that try to push vehicle out off its path , on the other hand there are resisting forces try to keep the vehicle on its path. Those include the friction between road surface and tires and forces resulting from sloping the highway cross section. When a vehicle on rural highway with high embankment the wind Pressure will play an important role in force system acting on vehicle because of increasing in wind pressure intensity at these conditions (rural highway, i.e open areas, high embankment). The purpose of this paper is to present a new equation for horizontal curve radius determination taking in to account the wind force effect in addition to other forces acting on vehicle The resulting equation relates vehicle length, height and weight and the wind pressure as well as the other factors in traditional equation. Effect of each parameter on design radius was investigated for the case where the wind direction is acted with the same centrifugal force direction. It has been found that the required minimum radius increase with the decreasing of vehicle weight or in the other words the vehicle permitted speed decrease with the decreasing of vehicle weight. On the other hand, the required curve radius increases with vehicle height increasing. Consequently, permitted height of bags loaded on a truck is related to the type of loads. Derived equation can also be used for estimation of the permitted truck speed on existing roads especially in case of bad weathers The comparison between the traditional and suggested equation showed that maximum difference is about 160 % which results at high wind pressure while the difference is up to 20 % for low wind pressure