The main objective of this study is to examine the impact of moisture concrete of clayey soil on the concrete slabs placed directly over it. This experimental study presents the mechanical properties of the concrete slab when placed on different clayey soil moisture content ranging from 0% to the optimum moisture content of 35%. The tests were performed on soil concrete specimens of 25*30*50 mm exposed to sprayed water curing conditions for 28 days. Tests of compressive strength, ultrasonic pulse velocity, crack depth and crack width were investigated through this paper. An ejection relationship between compressive strength of concrete and water content in the soil was observed, with a 26% increase with water increasing from 0% to 35%. The opposite was observed in the ultrasonic pulse velocity test, with a decrease of 58% from 0% to the highest water content ratio. As for crack depth and width, it recorded the highest depth and lowest width at 0% water content due to the increased susceptibility of the soil to the absorption of water from the concrete when it’s totally dry. The experiment has shown that the soil moisture content is considered as a critical factor in controlling concrete cracking, and its variation has considerable implications for concrete crack growth.
ABSTRACT
A field experiment was carried out in the fields of the college of agricultural engineering sciences, university of Baghdad during the fall season of 2021, in order to find out which of the cultivated genotypes of maize are efficient under nitrogen fertilization. The experiment was applied according to a RCBD (split plot design with three replications). The genotypes of experiment (Baghdad, 5018 and Sarah) and supplying three levels of nitrogen fertilizer, which are N1 (100 kg/ha), N2 (200 kg/ha) and N3 (300 kg/ha), the results of the statistical analysis are showed the superiority of the cultivar Sarah in the trait of number of days until 50% silking, chlorophyll
... Show MoreWhen the flange of a reinforced concrete spandrel beam is in tension, current design codes and specifications enable a portion of the bonded flexure tension reinforcement to be distributed over an effective flange width. The flexural behavior of the RC L-shaped spandrel beam when reinforcement is laterally displaced in the tension flange is investigated experimentally and numerically in this work. Numerical analysis utilizing the finite element method is performed on discretized flanged beam models validated using experimentally verified L-shaped beam specimens to achieve study objectives. A parametric study was carried out to evaluate the influence of various factors on the beam’s flexure behavior. Results showed that
... Show MoreThis investigation integrates experimental and numerical approaches to study a novel solar air heater aimed at achieving an efficient design for a solar collector suitable for drying applications under the meteorological conditions of Iraq. The importance of this investigation stems from the lack of optimal exploitation of solar energy reaching the solar collector, primarily attributable to elevated thermal losses despite numerous designs employed in such solar systems. Consequently, enhancing the thermal performance of solar collectors, particularly those employed in crop drying applications, stands as a crucial focal point for researchers within this domain. Two identical double-pass solar air heaters were designed and constructed for
... Show MoreRisk identification and assessment can be analysed using many risk management tools. Fishbone diagram is one of these techniques which can be employed, for the identification of the causes behind the construction failure, which has become a phenomenon that often gets repeated in several projects. If these failures are not understood and handled scientifically, it may lead to disputes between the project parties. Additionally, the construction failure also leads to an increase in the project budget, which in turn causes a delay in the completion of the projects. Punching shear in reinforcement slab may be one of the reasons for construction failures. However, there are many doubts about other causes that lead to this failure as w
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All central air conditioning systems contain piping system with various components, sizes, material, and layouts. If such systems in operating mode, the flow in piping system and its component such as valves can produce severe vibration due to some flow phenomenon’s. In this research, experimental measurements and numerical simulation are used to study the flow-induced vibration in valves. Computational fluid dynamics (CFD) concepts are included with one-way and two-way fluid-structure interaction concepts by using finite element software Package (ANSYS 14.57). Detection analysis is performed on flow characteristics under operation conditions and relations with structural vibration. Most of
... Show MoreExperimental and numerical investigations of the centrifugal pump performance at non-cavitating and cavitating flow conditions were carried out in the present study. Experiments were performed by applying a vacuum to a closed-loop system to investigate the effects of the net positive suction head available (NPSHa), flow rate, water temperature and pump speed on the centrifugal pump performance. Accordingly, many of the important parameters concerning cavitation phenomenon were calculated. Also, the noise which is accompanied by cavitation was measured. Numerical analysis was implemented for two phase flow (the water and its vapor) using a 2-D simulation by ANSYS FLUENT software to investigate the internal flow of centrifugal pump under c
... Show MorePermanent deformation in asphalt concrete pavements is pervasive distress [1], influenced by various factors such as environmental conditions, traffic loading, and mixture properties. A meticulous investigation into these factors has been conducted, yielding a robust dataset from uniaxial repeated load tests on 108 asphalt concrete samples. Each sample underwent systematic evaluation under varied test temperatures, loading conditions, and mixture properties, ensuring the data’s comprehensiveness and reliability. The materials used, sourced locally, were selected to enhance the study ʼs relevance to pavement constructions in hot climate areas, considering different asphalt cement grades and con- tents to understand material variability ef
... Show MoreThe aim of this study is to investigate the behavior of composite castellated beam in which the concrete slab and steel beam connected together with headed studs shear connectors. Four simply supported composite beams with various degree of castellation were tested under two point static loads. One of these beams was built up using standard steel beam, i.e. without web openings, to be a reference beam. The other three beams were fabricated from the same steel I-section with various three castellation ratios, (25, 35, and 45) %. In all beams the concrete slab has the same section and properties. Deflection at mid span of all beams was measured at each 10 kN load increment. The test results show that the castellation process leads to
... Show MoreThis work is an experimental investigation for single basin-single slope solar still coupled with an evacuated tube solar collector. The work is carried out under the climatic conditions of Baghdad city (33.2456º North and East latitude, 44.3337º longitude) through certain days of the months of the year 2019 to study the impact of using evacuated tube solar collector on the daily productivity and efficiency under the outdoors climatic conditions. It was found that using the evacuated tube solar collector increase daily productivity from 2.175 kg/ to 2.95 kg/ for 9 hours (35.63 %) for clear days, also an enhancement about 10.97 % in daily efficiency.
This work introduces a newly synthesized triazole derivative, 5-([(2-furanyl)methyl]-thiomethyl)-4-(naphtha-2-yl)-3-hydroxyl-4H-1,2,4-triazole (FTNT), as an effective corrosion inhibitor for carbon steel A106 G/B in 0.1 M HCl solution. The structure of the novel derivative was confirmed by FTIR, 1 H NMR, and 13 C NMR spectra. Potentiodynamic polarization measurements reveal that FTNT markedly suppresses corrosion, with inhibition efficiency reaching 81.6% at 600 ppm. Thermodynamic analysis indicates spontaneous, physisorption/chemisorption-augmented adsorption of FTNT on the steel surface, best described by the Freundlich isotherm. Atomic force microscopy (AFM) surface examination demonstrated that a protective FTNT coating precipitated on
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