Articles in This Issue
Abstract
The purpose of this paper is to investigate the relationship between the Ultrasonic Pulse Velocity (UPV) and the compressive strength and the flexural strength of hardened concrete when subjected to different concentrations of sulfate attacks. The specimens used in the studies were made of concrete with different water-cement ratios (w/c). The UPV measurement and compressive and flexural strengths tests were carried out for concrete specimens of ages (4-40) days. The experimental results show that the relationship between UPV and the compressive and the flexural strengths of concrete is significantly influenced by age and the concentration of sulfate attack. The UPV and the compressive strength of concrete grow with age, but the growth rate varies with w/c ratio. It is found that with the same concentration of sulfate attack, a clear relationship curve can be drawn to describe the UPV and compressive and flexural strengths of hardened concrete. This paper presents the UPV-strength relationship curves for concrete having different (w/c) ratios subjected to different concentrations of sulfate attack. These curves are thought to be suitable for prediction of hardened concrete strength with a measured UPV value when sulfate attack is considered. It is concluded that the UPV increases with the increase of the compressive and flexural strength. The observed range for UPV was (3.5 to 4.75 km/sec) corresponds to (24 to 28.5 N/mm2) for compressive strength and to (4.6 to 6.5 N/mm2) for flexural strength. The UPV decreases with the increase of the concentration of sulfate exposure. The obtained maximum reduction in UPV was 31.6% with respect to the control spacemen at age of 40 days.
Abstract
In this paper three material with equal amount have been chosen to make a mixture, these materials are sand (passing sieve no. 1.18, porosity 0.41), activated carbon (passing sieve no. 4.75, porosity 0.51), crushed bricks (passing sieve no. 20, porosity 0.47), the mixture was used as a bio-filtering media , placed to a height of (1.15) m in a cylindrical filter with diameter of (300)mm and a height of (2)m which is designed and constructed from (PVC). The filter is equipped with three piezometers fixed at three point along the height of the cylindrical filter, in addition to three overflows at different height, and an outlet with control valve. On May 2010 the filter was operated with a synthetic wastewater similar to domestic sewage in order to determine the hydraulic and sanitary characteristics of the filter. Then the feeding of waste water was continued for 3 weeks in order to stimulate the growth of bio-film. On June 2010 the filter was operated with gray water to determine the change in filter characteristics after the bio-film growth, and to evaluate filter efficiency to treat this water for the purpose of reuse. The outcome of this work showed that the mixed media bio-filter, to a certain extent, is similar in hydraulic characteristics (pressure drop and hydraulic load) to granular activated carbon bio-filter, head loss at (1000) mm depth is (59%) of initial pressure, the growth of bio-film leads to increase in head loss by (43%), decrease in flow by (25|%), decrease in pressure by (16%). According to removal efficiency of pollutants, the results shows an efficient removal of BOD5 (86%), turbidity (96%), TDS (81%) at a retention time (60 minute).
Abstract
In this paper an experimental study of the effect of grooves on initial peak load and work done by plastic deformation of material is presented. A series of tests were conducted on polyvinylchloride PVC circular tubes with grooves and without grooves loaded statically and axially. The specimens with grooves were tested with constant depth of groove and constant axial length of groove. Load-deflection characteristics for the PVC circular tubes specimens and the influence of collapsing load were illustrated in this work. The experimental results were compared with proposed mathematical model giving a good agreement. Also in this work, it was showed that the value of plastic work decreases with increasing the number of grooves.
Abstract
The look for the new water resources and the optimal using of available water is very important because of high change in the climate of the earth, the dry wave in the region as well as the decreases of the water inflow to the Euphrates and the tigress river because of the building of the dams upstream the basin in Turkey and Syria. In the present study, four biggest catchments area in the Iraqi western desert (wadi Horan, wadi AlGhadaf, wadi Ubayiad, wadi Tubul) were selected to study the hydrologic properties to determine the best region for the water harvesting because these areas include the most water harvesting project such as the small dams. Present hydrologic study was depended on the available data to determine the amount of runoff that can be harvested according to measuring data of metrological station in the region with the method of hydrograph for analysis. For the period (1971-1976) the study showed wadi Al-ghdaf is the best region for water harvesting according to the number of floods to the cathment area (44 floods) with water volume (1047*106m3), and the average water harvesting (7098.64 m3/km2). The second is wadi Horan the number of floods to the cathment area (33 floods) with water volume (2033.29*106m3), and the average water harvesting (6115.16 m3/km2). Then wadi al Ubyaid number of floods to the cathment area (21 floods) with water volume (405.197*106m3) and the average water harvesting (2493.52 m3/km2). The last one is wadi Tubul with number of floods to the cathment area (18 floods) with water volume (909.36 and the average water harvesting (2231.6 m3/km2)*106m3)
Abstract
The research aims at revealing the morphometric characteristics of wadi Jbab Basin, which include areal ,relief characteristics, and the shapes of cross- sections of the valley. The hydrological properties of Jbab basin were studied to estimate the amount of water received by its catchment area during rain falls, thus, the appropriate places for the construction of dams and reservoirs for use in water harvesting can be determined. The area under study is located in Iraqi western plateau , between the latitudes of 33º 55' 45"N to 34 º 27' 50" N, and longitudes 41º 24' 30" E to 41º 43' 00" E. Remote sensing technology (RS) and geographic information systems (GIS) were used to reach the objectives of this research, so Digital Elevation model (DEM) for the year 2009 was brought to program (Arc GIS 9.3) and detected the basin and valley of Jbab automatically by using the hydrological analysis method. The area under study is characterized by the drought with a deficit of water in all months of the year where the highest in the month of July, amounting to 324.5 mm and the lowest in January, 10.92 mm. The geological formations prevail formations limestone, with sandy soil to sand-clay mixture, with lack of density in the vegetation. The average slope in basin of Wadi Jbab is 0.25 degree. There are five ranks of river, the sum of their tributaries 676 tributary within an area of 986.6 km ², and its perimeter is 214.3 km , it is also noticed the form of the basin tends to form a rectangle, with three places suitable for the construction of dams and reservoirs depending on the morphometric and hydrologic information that related to the area of research.
Abstract
The object of this paper was reduced the heat transferred quantities from or to internal building space by covering it's external walls with many materials, therefore, the researcher build the (1x1x2) m room sample at 3rd floor for building in Baghdad city (L = 33.2 N°), and (1x2)m wall has East orientation , while the other surfaces were insulated by 200 mm styropor sheets, and using Air – Conditioner 0.5 Ton of refrigeration to afford the standard thermal comfort. The researcher found that, the metal sheet painted with thermal plastic paint with 10 mm thermal insulation used as a cover layer for ordinary wall saved 57% from electrical energy consumption in Air-Conditioner, while used that material without insulation layer gives 46.2% , hollow plastic board (for decorative used) gives 42.5% , hollow faced brick with thermal insulation gives 40.22%, solid flooring brick with thermal insulation gives 39.5% , colour metal sheets with air – gap gives 36.4%, asbestos – cement board coated by reflective aluminum paint gives 34%, the ceramic with thermal insulation gives 31.9%, while all the material – marble , porcelene , hallan stone , fiberglass sheets with 10 mm thermal insulation will gives the electrical energy reduction percentage less than 30% .
Abstract
Fallujah is one of Iraqi cities which need a comprehensive transport plan for its increased urban development and have increasing in umber of moving vehicles, caused an increasing in population with changes in the standard of living and daily trips especially at the central area, which causes jamming in transportation network. For the purpose of study, the study area in the north sector of Fallujah city is considered as one sector consists of (10) zones containing about (11954) dwelling units. Home interview survey was made of random sample which represent 5% of the study area population, and data collected through this zone. Data was related to socioeconomic characteristics of the population. The collected information solve by using the method multi – linear regression by a package(SPSS). The total persons trips per dwelling unit and various purposes were investigated. A trip production model in Fallujah city, through find relationship between socioeconomic characteristics (car ownership, family income, employee, family no., population, family size, time and cost of trip, distance to the center and area of household unit). It was found that the number of families is the most influential variable to trip production model.
Abstract
Value Engineering is one technique to distributed the resources fairly and perfect progress with honest meaning to decrease the expenditure , perform functions to improve the value element in project through decreasing the cost and developing the quality as well as choosing the better alternative to get the best quality . The research studies the value engineering technique by a field surveying and questionair submitted to different project personal in ALanbar government trough many stages beginning primary and finial design to construction project stage and the last operating and maintenance stage. Many site visits and personal interviews were carried out with their actual onsite experience on some of construction projects. Many useful conclusions and recommendations, one of them the researcher recommended to use the value engineering in contracts which have been support the economic national and save money to finance other projects.