This paper introduces experimental results of eighteen simply supported reinforced concrete beams of cross sections ( ) and length 3000 mm to study the effect of lacing reinforcement on the performance of such beams under static and fatigue loads. Twelve reinforced concrete beams (two of them are casted with vertical shear reinforcement used as control beams) are tested under four points bending loading with displacement control technique and six laced reinforced concrete beams were exposed to high frequency (10 Hz) by fixing the fatigue load in each cycle. Three parameters are used in the designed beams, which are: lacing bar diameter (4mm, 6mm, and 8mm), lacing bar inclination angle to horizontal , and lacing steel ratio depending on number of lacing bar in each longitudinal face of beam and lacing bar diameter. The comparison results of experimental tests revealed that the ultimate loads of laced reinforced concrete beams are higher than the conventional reinforced concrete beams due to increasing lacing bar diameter, angle of inclination lacing bar, and lacing steel ratio, while the deflection is reduced. Also, the laced reinforced concrete beams can safely withstand the fatigue loading.
In this research a theoretical study has been carried out on the behavior and strength of simply supported composite beams strengthened by steel cover plate taking into consideration partial interaction of shear connectors and nonlinear behavior of the materials and shear connectors. Following the procedure that already has been adopted by Johnson (1975), the basic differential equations of equilibrium and compatibility were reduced to single differential equation in terms of interface slip between concrete slab and steel beam. Furthermore, in order to consider the nonlinear behavior of steel, concrete and shear connectors, the basic equation was rearranged so that all terms related to materials are isol
... Show MoreSeeds of five cultivars of oats (Avena sativa) were introduced from Italy in 2009. Seeds were propagated on the farm of the Dept. of Field Crops Sci. / Coll. of Agric. / Univ. of Baghdad in the season 2009 – 2010. The cultivars Anatolia, Alguda, Hamel, Pimula and Genzania were planted under 3 irrigation intervals; 3, 4 and 5 weeks to give water depth of 480, 400 and 320 mm, respectively . The depth of water was 80 mm each irrigation. A factorial experiment with RCBD of 4 replicates was conducted in 2 consecutive seasons in 2010 – 2011 and 2011 – 2012. The cultivar Alguda gave highest grain yield (8.07 t/ ha) under 480 mm, and 7.02 t / ha average of 3 water depths. This cultivar was characterized by high growth rate (13.2 g/m2/ d) that
... Show MoreOne of the Iraqi geotechnical problems is the presence of gypseous soils covering about (27-36) percentage of Iraq soils containing gypsum between (10-70) ratios. The main reason for soil problematic is the gypsum dissolution when these soils are inundated. However, the soluble gypsum can be leached out of the soil particles, so these problems can be led to cracking, tilting, and collapsing the related soil structure and changing the soil properties. The aim of this work is to investigate the performance of under-reamed piles as a new, improved method to reduce the moisture sensitive and the primary triggering mechanism for the volume reduction of collapsible soil, which is considered as a non-elastic deformation; this was done by c
... Show MoreThis research is devoted to investigate relationship between both Ultrasonic Pulse Velocity and Rebound Number (Hammer Test) with cube compressive strength and also to study the effect of steel reinforcement on these relationships.
A study was carried out on 32 scale model reinforced concrete elements. Non destructive testing campaign (mainly ultrasonic and rebound hammer tests) made on the same elements. About 72 concrete cubes (15 X 15 X15) were taken from the concrete mixes to check the compressive strength.. Data analyzed.Include the possible correlations between non destructive testing (NDT) and compressive strength (DT) Statistical approach is used for this purpose. A new relationships obtained from correlations results is give
This study is a numerical investigation of the performance of reinforced concrete (RC) columns after fire exposure. This study aims to investigate the effect of introducing lateral ties and using the RC jacket on improving post-fire behavior of these columns, the effect of the duration of the fire on ultimate load of columns. The analysis was performed through ABAQUS, a 3D – non-linear finite element program. 4 m tall lengthening square RC column with a cross- section of 0.4 m × 0.4 m was used as a test specimen. The RC column was reinforced by 4Ø28 mm longitudinal bars bonded by steel tie bars of Ø10 mm spaced at 400 mm. The firing temperature was increased to 60
The present work covers the analytical design process of three dimensional (3-D) hip joint prosthesis with numerical fatigue stress analysis. The analytical generation equations describing the different stem constructive parts (ball, neck, tour, cone, lower ball) have been presented to reform the stem model in a mathematical feature. The generated surface has been introduced to FE solver (Ansys version 11) in order to simulate the induced dynamic stresses and investigate the effect of every design parameter (ball radius, angle of neck, radius of neck, neck ratio, main tour radius, and outer tour radius) on the max. equivalent stresses for hip prosthesis made from titanium alloy. The dynamic loading case has been studied to a stumbling ca
... Show MoreThis study deals with the aircraft wing analysis (numerical and experimental) which subjected to fatigue loading in order to analyze the aircraft wing numerically by using ANSYS 15.0 software and experimentally by using loading programs which effect on fatigue test specimens at laboratory to estimate life of used metal (aluminum alloy 7075-T651) the wing metal and compare between numerical and experimental work, as well as to formulate an experimental mathematical model which may find safe estimate for metals and most common alloys that are used to build aircraft wing at certain conditions. In experimental work, a (34) specimen of (aluminum alloy 7075-T651) were tested using alternating bending fatigue machine rig. The t
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Purpose: Providing practical knowledge of the requirements of a detailed feasibility study for selecting the investment project.
Findings: Directing the private sector towards investing in productive projects - the pre-cast reinforced concrete project - as it achieves a financial return as well as providing Providing foreign currencies by reducing imports and exploiting available natural resources
Practical implications: The importance of a detailed feasibility study to determining whether the project can be implemented or not.
The precast concrete method is one of the best modern c
... Show MoreEnvironmental sustainability is described as one that avoids the depletion or deterioration of natural resources, while also allowing for the preservation of long-term environmental quality. By practicing environmental sustainability, we may assist to guarantee that the requirements of today’s population are satisfied without risking the capacity of future generations to meet their own needs in the future. Engineers in the field of concrete production are becoming increasingly interested in sustainable development, which includes the utilization of the locally available materials in addition to using the agricultural and industrial waste in construction industry as one of the possib