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Post-fire serviceability and residual strength of composite post-tensioned concrete T-beams
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Abstract<p>In this study, the response of ten composite post-tensioned concrete beams topped by a reinforced concrete deck with adequate reinforcing shear connectors is investigated. Depending on the concrete compressive strength of the deck slab (20, 30, and 40 MPa), beams are grouped into three categories. Seven of these beams are exposed to a fire attack of 700 and 800 °C temperature simultaneously with or without the presence of a uniformly distributed sustained static loading. After cooling back to ambient temperature, these composite beams are loaded up to failure, using a force control module, by monotonic static loading in a four-point-bending setup with two symmetrical concentrated loads applied in the middle third of the effective span. The objectives of this study include investigating the behavior of the composite prestressed concrete beams under and after the exposure to a direct fire flame, as well as finding their residual load-carrying capacity. Tests demonstrate significant deteriorations caused by exposure to high temperatures associated with the increase of the member’s camber. The increase of the midspan camber after heating exposure reached approximately 200%. On the other hand, the 1-h steady-state exposure of test specimens to temperatures of 700 and 800 °C led to reduce the load-carrying capacity of the heat-deteriorated beams up to 45% and 54%, respectively.</p>
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Publication Date
Mon Aug 01 2016
Journal Name
Journal Of Engineering
Non-Linear Behavior of Strengthened Steel-Concrete Composite Beams with Partial Interaction of Shear Connectors
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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

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Publication Date
Thu Oct 01 2015
Journal Name
Applied Research Journal
Experimental Study of the Behavior of Composite Concrete Castellated Steel Beams Subjected to Pure Bending
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The 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

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Publication Date
Sun Mar 01 2015
Journal Name
Journal Of Engineering
Finite Element Investigation on Shear Lag in Composite Concrete-Steel Beams with Web Openings
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In this paper, effective slab width for the composite beams is investigated with special emphasis on the effect of web openings. A three dimensional finite element analysis, by using finite element code ANSYS, is employed to investigate shear lag phenomenon and the resulting effective slab width adopted in the classical T-beam approach. According to case studies and comparison with limitations and rules stipulated by different standards and codes of practice it is found that web openings presence and panel proportion are the most critical factors affecting effective slab width, whereas concrete slab thickness and steel beam depth are less significant. The presence of web opening reduces effective slab width by about 21%.

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Publication Date
Tue Dec 05 2023
Journal Name
Engineering, Technology &amp; Applied Science Research
The Fire Effect on the Performance of Reinforced Concrete Beams with Partial Replacement of Coarse Aggregates by Expanded Clay Aggregates
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This paper aims to investigate the flexural behavior of reinforced concrete beams considering fire resistance by adding Lightweight Expanded Clay Aggregates (LECA) to the concrete mix as partial coarse aggregate replacement. LECA is a type of porous clay with a uniform pore structure with fine, closed cells and hard, tightly sintered skin. The experimental work comprised four reinforced self-compacted concrete beams. All the specimens were identical in their geometrical layout of 1600×240×200 mm, reinforcement details, and support condition (simply supported). For all the beams, the main reinforcement was provided by two bars, each having a diameter of 12 mm, while a bar of 6 mm diameter was employed for the top and shear reinforc

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Publication Date
Wed Dec 30 2020
Journal Name
Al-kindy College Medical Journal
Iraqi women Attitude towards Immediate Post-partum/ Post-abortion Contraception: a multi-institutional study
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Background: Immediate postpartum contraceptive and post abortion contraception methods are effective safe methods and are becoming a standard practice in many countries, yet it is not widely used in Iraq.

Aims: this study: is designed to assess the attitude and willingness of women to immediate contraception after giving birth or abortion and their satisfaction to previous use.

Methods and Material: Four hundred thirty-four women were surveyed in the labor word immediately after giving birth/ abortion. Their knowledge, attitude and contraception use were assessed according to the response they reported to a given questionnaire.

Results: women were not sure abo

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Publication Date
Fri Dec 01 2023
Journal Name
Case Studies In Construction Materials
Experimental and environmental investigations of the impacts of wood sawdust on the performance of reinforced concrete composite beams
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Publication Date
Sun Jan 03 2016
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Alcohol and drug abuse in post-conflict Iraq
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Background: The 2006-2007 Iraqi Mental Health survey (IMHS) reported surprisingly low prevalence of alcohol and drug abuse in the Iraqi population. Since then anecdotal and clinical reports have suggested that abuse of alcohol and drugs in Iraq has increased. To investigate this possibility, we conducted a survey of drug and drug abuse at youth centers in Baghdad.
Objective: To investigate this possibility, we conducted a survey of drug and drug abuse at youth centers in Baghdad.
Patients and methods: A total of 2678 persons were included in this survey with male to female ratio of 3.8:1. They were randomly selected from youth centers located in different sectors in Baghdad (Sader city, Al-Rusafa side and Al-Karkh side). Composite

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Publication Date
Sun Nov 01 2015
Journal Name
Journal Of Dentistry
New functional and aesthetic composite materials used as an alternative to traditional post materials for the restoration of endodontically treated teeth
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Objectives To tailor composites of polyethylene–hydroxyapatite to function as a new intracanal post for the restoration of endodontically treated teeth (ETT). Methods Silanated hydroxyapatite (HA) and zirconium dioxide (ZrO2) filled low-density polyethylene (LDPE) composites were fabricated by a melt extrusion process and characterised using infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The flexural strength and modulus were determined in dry state and post ageing in simulated body fluid and fractured surfaces analysed by SEM. The water uptake and radiographic appearance of the experimental composites were also measured and compared with a commercially known endodontic fibre

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Publication Date
Mon Dec 31 2018
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Colostomy closure in post Conflict Iraq
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Background: Colostomy minimizes the risk of leakage at expense of requiring a second operation. In Iraq, published on colostomy closure in penetrating abdominal wall injuries is scarce.

Objective: to Study the prognosis of colostomy closure in post-conflict patients in Iraq.

J Fac Med Baghdad 2018; Vol.60, No.3 Received: June, 2018 Accepted: Oct., 2018

Published: Dec.2018

 

 

 

Method: This is a retrospective study of 52 patients subjected to colostomy closure, recruited for the period 2008 to 2009

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Crossref
Publication Date
Wed Nov 24 2021
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Colostomy closure in post Conflict Iraq
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Background: Colostomy minimizes the risk of leakage at expense of requiring a second operation. In Iraq, published on colostomy closure in penetrating abdominal wall injuries is scarce.

Objective: to Study the prognosis of colostomy closure in post-conflict patients in Iraq.

Method: This is a retrospective study of 52 patients subjected to colostomy closure, recruited for the period 2008 to 2009 from Al-Yarmouk Teaching Hospital and Children Central Teaching Hospital. Demographic data and information about colostomy (type, methods of preparation … etc.) were studied.

Results: Trauma was noticed in 57.7% patients. Transverse colon was the commone

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