A long-span Prestressed Concrete Hunched Beam with Multi-Opening has been developed as an alternative to steel structural elements. The commercial finite element package ABAQUS/CAE version 2019 has been utilized. This article has presented the results of three-dimensional numerical simulations investigating the flexural behaviour of existing experimental work of supported Prestressed Concrete Hunched Beams with multiple openings of varying shapes under static monotonic loads. Insertion openings in such a beam lead to concentrate stresses at the corners of these openings; as a result, extensive cracking would appear. Correlation between numerical models and empirical work has also been discussed regarding load displacement and crack development, and the obtained outcomes demonstrate a good agreement with the experiments. The ratio of ultimate loads and deflection of the beams tested in the investigation to those of numerical models was 0.98 and 0.97, respectively. So, finite element analysis can be regarded as a behaviour-trustworthy technique for simulating the non-linear behaviour of prestressed concrete rafters with multi-openings from the point of view of complexity, hardly, time-keeping, human effort, and cost.
Several million tons of solid waste are produced each year as a result of construction and demolition activities around the world, and brick waste is one of the most widely wastes. Recently, there has been growing number in studies that conducted on using of recycling brick waste (RBW) to produce environmentally friendly concrete. The use of brick waste (BW) as potential partial cement or aggregate replacement materials is summarized in this review where the performance is discussed in the form of the mechanical strength and properties that related to durability of concrete. It was found that, because the pozzolanic activity of clay brick powder, it can be utilized as substitute for cement in replacement level up t
... Show MoreNowadays, the use of recycled waste construction materials instead of aggregates is becoming popular in construction owing to its environmental benefits. This paper presents an experimental and analytical campaign to study the behavior of axially loaded columns constructed from recycled aggregates. The latter was used instead of natural aggregates, and they were collected from the waste of previous concrete constructions. Different concrete mixtures made from varying amounts of recycled aggregates ranged from 0 to 50% of the total coarse aggregate were conducted to achieve 28 MPa. The effect of steel fibers is another investigated variable with volumes ranged from 0 to 2% concerning concrete’s mixture. The experimental
... Show MoreThis research is devoted to study the strengthening technique for the existing reinforced concrete beams using external post-tensioning. An analytical methodology is proposed to predict the value of the effective prestress force for the external tendons required to close cracks in existing beams. The external prestressing force required to close cracks in existing members is only a part from the total strengthening force.
A computer program created by Oukaili (1997) and developed by Alhawwassi (2008) to evaluate curvature and deflection for reinforced concrete beams or internally prestressed concrete beams is modified to evaluate the deflection and the stress of the external tendons for the externally strengthened beams using Matlab
This research aims at calculating the optimum cutting condition for various types of machining methods, assisted by computers, (the computer program in this research is designed to solve linear programs; the program is written in v. basic language). The program obtains the results automatically, this occur through entering the preliminary information about the work piece and the operating condition, the program makes the calculation actually by solving a group of experimental relations, depending on the type of machining method (turning, milling, drilling). The program was transferred to package and group of windows to facilitate the use; it will automatically print the initial input and optimal solution, and thus reduce the effort and t
... Show MoreThe fauna of bees (Hymenoptera, Apoidea) from different regions of Iraq is surveyed in this study; there were 16 species, 13 genera that belong to four families which are collected in this investigation.
Also, all the species that are recorded for Iraq in previous investigations are revised; totally there are 110 species, 32 genera belonging to five families: Apidae, Andernidae, Colletidae, Halictidae and Megachilidae were listed.
The nonlinear refractive (NLR) index and third order susceptibility (X3) of carbon quantum dots (CQDs) have been studied using two laser wavelengths (473 and 532 nm). The z-scan technique was used to examine the nonlinearity. Results showed that all concentrations have negative NLR indices in the order of 10−10 cm2/W at two laser wavelengths. Moreover, the nonlinearity of CQDs was improved by increasing the concentration of CQDs. The highest value of third order susceptibility was found to be 3.32*10−8 (esu) for CQDs with a concentration of 70 mA at 473 nm wavelength.
Molar conductivity of different concentrations of thymine and adenosine in water , sodium acetate and ammonium chloride solution at different temperatures , 283. 15-323.15 K has been determined from direct conductivity measurements , examination of aqueous mixture of thymine and adenosine with Onsager equation reveal deviation from linearity at high concentration .This deviation was explained in term of molecular interaction . Ostwald dilution law also examined with the above mixtures lead to calculation of limiting molar conductivities and dissociation constants of both nucleic acid in water , sodium acetate and ammonium chloride. The agreement between the values obtained for Onsager equa
... Show MoreBackground: Denture lining materials are widely used in prosthodontic treatment and management of traumatized oral mucosa. A contaminated prosthesis can provide a source of cross-contamination between patients and dental personnel as well as a cause for denture stomatitis. Therefore, denture disinfection has been recommended as an essential procedure for maintenance of a healthy oral mucosa. This study investigated the effect of SOLO disinfectant solution on some properties of different denture lining materials. Materials and methods: Three different solutions were used in this study; SOLO disinfectant solution, sodium hypochlorite solution, and water on three types of acrylic denture lining materials; hot cure, cold cure, and soft acrylic
... Show MoreThe present work aimed to study the efficiency of thermal osmosis process for recovery of water from organic wastewater solution and study the factors affecting the performance of the osmosis cell. The driving force in the thermo osmosis cell is provided by a difference in temperature across the membrane sides between the draw and feed solution. In this research used a cellulose triacetate (CTA), as flat sheet membranes for treatment of organic wastewater under orientation membrane of active layer facing feed solution (FS) and draw solution (DS) is placed against the support layer. The organic materials were phenol, toluene, xylene and BTX (benzene, toluene, and xylene) used as feed solution. The osmotic agent in draw solution was
... Show MoreMillions of lives might be saved if stained tissues could be detected quickly. Image classification algorithms may be used to detect the shape of cancerous cells, which is crucial in determining the severity of the disease. With the rapid advancement of digital technology, digital images now play a critical role in the current day, with rapid applications in the medical and visualization fields. Tissue segmentation in whole-slide photographs is a crucial task in digital pathology, as it is necessary for fast and accurate computer-aided diagnoses. When a tissue picture is stained with eosin and hematoxylin, precise tissue segmentation is especially important for a successful diagnosis. This kind of staining aids pathologists in disti
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