Muthanna Journal of Engineering and Technology(MJET)

The radioactive properties of building materials used for the construction of habitable structures in Iraq were investigated in this study. In the framework of this paper, ten samples of commonly used building materials (bricks and rocks used for incasing) were collected from ten Iraqi provinces for radiometric analysis. The activity concentrations of natural radionuclides in the selected samples were determined by gamma ray spectrometry using sodium iodide (NaI) detector. Based on the results of this study, the use of rocks for incasing manufactured in Al-Rumadi is considered to be unsafe for human habitation from radiological points of view due to relatively high background radioactivity. The radioactivity levels for building materials for the remaining investigated areas were well within the permissible limits.

This study investigated the influence of type of concrete (self compacting concrete (SCC) and normal concrete (NC)) and compressive strength (30, 50 and 62 MPa) on the flexural and shear behavior of reinforced concrete beams, as well as punching shear of slabs. To achieve these targets, 18 beams and 6 slabs are equipped, tested and assessed. The tested beams were divided into three groups, the first group consists of six beams failed in flexure, the second group contains six beams without web reinforcement failed in shear with shear span/depth ratios of 3 (slender beams), the third group consists of six beams without web reinforcement failed in shear with shear span/depth ratio of 1 (deep beams), each group consisted of three SCC and three NC geometrically similar rectangular beams of different concrete strengths. Test results indicated that, for beams failing in flexure, SCC beams showed similar ultimate load to NC beams. For slender beams failing in shear, the ultimate load for beams with fc’ of about 32 and 48 MPa, NC beams showed 6.75 % higher ultimate load compared with SCC beams, but beams with fc’ of about 62 MPa, SCC and NC beams showed almost the same ultimate load value. For deep beams, no considerable difference in ultimate loads for SCC and NC beams was noticed. For the six geometrically similar slabs (three slabs made with SCC and three slabs made with NC of different concrete strengths) which were designed to fail in punching shear, it was found that, SCC slabs exhibited 17.25 % higher ultimate punching shear load than NC slabs.

The aim of this study is to investigate the experimental behavior of reinforced concrete light weight concrete two-way slabs stiffened by CFRP strips to punching load and compare the results with the finite element model results. The experimental program includes testing a total of 14 slabs (800 x 800 x 70) and (800 x 800 x 90) mm. The slabs are divided into two groups; each group consists of seven slabs. In each group of seven slabs, one slab was left without strengthening as a reference slab, while each slab of the remaining six slabs has a different CFRP distribution. The effect thickness of slabs and shape of the CFRP distribution on the punching shear strength of slabs are studied. All slabs in this study are designed to fail in punching shear. During the test, the slabs are simply supported on all four edges and loaded centrally by a (75 x 75) mm column. Load deflection curves, cracking patterns and effect of variables on the test results are discussed. Experimental results showed that, the CFRP strengthening increased the ultimate punching load of the slabs by (9-26) %, also the first cracking load increased by (38-141) %. The strengthened slabs showed less deflection during loading by about 24% compared to the non- strengthened slabs. Increasing the slab depth gives changes to the slabs punching strength. The slabs are modeled by three dimension finite elements and non-linearly analyzed by the ANSYS program where the concrete is represented by the eight nodes solid element (solid 65) and the CFRP strips are represented by (3D shell 41) with a perfect bond between the CFRP and concrete slabs. Finite elements results showed a comparable results to laboratory tested slabs and the difference is not more 12% in ultimate load.

This paper introduces the design of rectangular multi-band H-shaped microstrip antenna with rectangular slot (RMSA). A special H-structure with constant substrate thickness was simulated for the proposed antenna, and the effects of different stub sizes on rectangular patch antenna performance were investigated. A balanced patch antenna has been designed and analyzed at frequencies of (1 to 6.5 GHz). COMSOL Multiphysics program was used for the simulation. The resonant frequencies and radiation characteristics were analysed. Different frequencies used for Radio Frequency Identification RFID, Worldwide Interoperability for Microwave Access (Wimax) and computer network applications were tackled.

This paper investigates the effect of soil-pile cap interaction on the dynamic behavior of the soil-pile system under vibrations. Vertical vibration tests were conducted using experimental models of pile footings embedded in a finite dry sand layer. The pile footings consist of two groups of circular piles with spacing/diameter (S/d) ratio equals to 5; the length/diameter (L/d) ratio for first group was 13.3 and for the second was 20. Each group includes models with different number of piles. A physical model made of steel box of dimensions of 700 × 700 mm and 800 mm in height was used for accommodation the test model. In order to study the effect of cap interaction, the first tests were conducted where a gap was left between the caps and sand surface as reference, and the second tests all caps in contact with sand surface. The maximum displacement amplitudes and the corresponding resonant frequencies of the experimental system were measured using vibration meter and accelometer fixed on the top of the pile cap. The results of both groups indicated that the pile cap interaction significantly increases the vertical amplitudes and increases slightly the resonant frequencies in different proportions.

This paper determines the coordination system pattern of traffic signal for four intersections in Cheras town at Malaysia. The data required for the study were mainly collected through video filming technique during the peak hour. Besides, the calculation and evaluation were constructed with simulation model software Traffic was used to evaluate the possible coordination of both signalized intersections. The calibration of delay, queues and journey times were practically measured. The results showed that the value of delay, journey time, and stops were reduced the before optimization from (F) LOS after optimization to (C) with performance index (PI). Simulation helps decision makers identify different possible options by analyzing enormous amounts of data. Hence, it can be used effectively to analyze traffic flow patterns and signal light timing at the traffic congestion.

A numerical simulation to investigate the performance of solar chimney power plant is presented. A small scale model of solar chimney power plant was modelled by using FLUENT software. The solar chimney power plants consist of three essential elements, glass roof collector, chimney (tower) and wind turbine. The output power of the system depends on the input velocity to wind turbine. The turbine inlet velocity is a function of collector – chimney junction type. To solve the governing equations of conservation of mass, momentum, energy. Do-intensity k and Ɛ equations the finite volume method was adopted by FLUENT software to model and analyze such system. The results showed that the geometry of entrance region (collector-chimney junction type) has an effect on the performance parameters especially air flow velocity. Using curved or rounded junction with deflector will improve system mass flow rate by 37.65% as compared with straight junction.

The main objective of the present study is to investigate the residential solid wastes characteristics and energy content in Hilla city in the middle of Iraq. The solid waste characteristics, and energy content of Hilla city were found by selecting one area, which represent different lifestyles. Data of samples were collected from 13 multi-storey buildings in the Tuhmaziya region in Hilla city through 2013. The refuse was classified into ten categories (food wastes, paper, plastics , glass, textiles, rubber, tin cans , wood, cardboard, and garden trimmings, etc). The food category was found to be 46.31% of the total weight, and moisture content of 37.52 %. The chemical formula of a residential solid waste of Hilla city was found to be C802.3 H2630.3 O1074.3 N18 with sulfur and without sulfur as C44.6 H146.1 O59.7 N. The energy content (dry basis) was found to be 12369 kJ/kg.

This research is devoted to investigate the effect of CFRP strips on the behavior and load carrying capacity of strengthened I-section reinforced concrete deep beams. The experimental program variables include configurations of CFRP, spacing between CFRP and type of loading (monotonic or cyclic load) on the behavior of strengthened deep beams. The experimental test results confirm that the strengthening technique of CFRP system is applicable and can increase the shear capacity for strengthened of RC beams. In this study, the ultimate load capacity of the strengthened beams ranged between 18% to 38% under monotonic load and between 11% to 26% under cyclic load over the ultimate load capacity of the reference beam. For beams including CFRP changing the spacing of the strips from 50mm to 20mm, increased the strength of the beam by 17%. For beams subjected to cyclic load the mode failure is nearly the same as that of beams subjected to monotonic load and the cyclic loading produced somewhat less brittle behavior in beam under cyclic loading.