A novel demountable shear connector for precast steel‐concrete composite bridges is presented. The connector uses high‐strength steel bolts, which are fastened to the top flange of the steel beam with the aid of a special locking nut configuration that prevents slip of bolts within their holes. Moreover, the connector promotes accelerated construction and overcomes typical construction tolerances issues of precast structures. Most importantly, the connector allows bridge disassembly, and therefore, can address different bridge deterioration scenarios with minimum disturbance to traffic flow, i.e. (i) precast deck panels can be rapidly uplifted and replaced; (ii) connectors can be rapidly removed and replaced; and (iii) steel beams can be replaced, while precast decks and shear connectors can be reused. A series of push‐out tests are conducted to assess the behavior of the connector and quantify the effect of important parameters. The experimental results show shear resistance, stiffness, and slip capacity significantly higher than those of welded shear studs along with superior stiffness and strength against slab uplift. Identical tests reveal negligible scatter in the shear load – slip displacement behavior. A design equation is proposed to predict the shear resistance with absolute error less than 8%.
Back ground: In Iraq, after 2003 had more
accidents of the shell, bullet and stab abdominal
wounds, more over colon injuries.
Objective: The aim of this study is to evaluate
the most appropriate management of penetrating
colon injuries, comparing the primary repair with
the diversion.
Methods: Eighty patient series with shell, bullet
and stab colonic injuries during 4.5 years period
from June 2006-december 2010 at Al-Yarmouk
teaching hospital. The study compared the use of
primary repair versus diversion, analyzing
variables such as sex, age, severity of injury and
mortality rate.
Results: there were total 80 patients ,62 (77.5%)
male and 18(22.5%) female .male :female ratio
3.4:1. the most
Require senior management of the state when developing the strategy the general budget to the clarity of the reasons that are based upon the ministries in the preparation of estimates of expenditure for the next year to justify the spending, and in the absence of targets, the ministry or government unit would not be in front, but be guided by the size of expenditure for the last year in addition to the percentage of represented an increase of appropriations required for the next year in light of the fiscal policy of the state, so the requested increase in appropriations to meet the desired increase in some of its activities and to meet the increase in salaries and prices. So must be available to the Ministry of criteria that coul
... Show MoreEncasing glass fiber reinforced polymer (GFRP) beam with reinforced concrete (RC) improves stability, prevents buckling of the web, and enhances the fire resistance efficiency. This paper provides experimental and numerical investigations on the flexural performance of RC specimens composite with encased pultruded GFRP I-sections. The effect of using shear studs to improve the composite interaction between the GFRP beam and concrete was explored. Three specimens were tested under three-point loading. The deformations, strains in the GFRP beams, and slippages between the GFRP beams and concrete were recorded. The embedded GFRP beam enhanced the peak loads by 65% and 51% for the composite specimens with and without shear connectors,
... Show MoreIn this study, a predicated formula is been proposed to find the shear strength of non-prismatic beams with or without openings. It depends on the contributions of concrete shear strength considering the beam depth variation and existing openings, shear steel reinforcements and defines the critical shear section, the effect of diagonal shear reinforcement, the effect of inclined tensile steel reinforcement, and the compression chord influence. The verification of the proposed formula has been conducted on the experimental test results of 26 non-prismatic beams with or without openings at the same loading conditions. The results reflect that the predicted formula finds the shear capacity of non-prismatic beams with openings, it is co
... Show MoreThe research on coordination polymers chemistry based on organic-metal framework with bridging ligands has accelerated during the past two decades. It is an interested hot topic in the synthetic inorganic chemistry, which allowed the fabrication of a variety of interested materials. These materials have shown a range of applications including light harvesting and magnetic properties. The thesis is divided in three chapters. The first chapter gives a general introduction on the development of self-assembled polymeric species based on transition metal. It is also covered a summary of the literature review on the current state of the art on self-assembled coordination ploymers. Furthermore, it includes a description on various relevant topics
... Show MoreThe general crisis of research methods in the social sciences
Research methodology: philosophy and techniques, founded by philosophers and applied by scientists, and no accurate application of techniques except with a deep understanding of philosophy, as a prerequisite. This fact is almost completely absent from the Iraqi and Arab academic mentality. This constituted one of the dimensions of the double crisis - theoretical and applied - of research methods in the social sciences. As first, there is no philosophy of science, neither as an independent material nor as an introductory subject, but not even an oral confirmation. Secondly, the advancement of quantitative research methods are presented without a background philosophy, as sol
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%. T
... Show MoreBackground: This study was performed to determine the effect of aging of different types of composite material restorations on: Shear bond strength (SBS) to light cure and no mix chemical cure orthodontic adhesives with sapphire bracket and the debonding failure sites. Materials and methods: One hundred forty four composite disks were made from three different composite resin materials which are: 3M Filtek Z250, 3M filtek Z350 and 3M Valux plus, each group with (48) disks each, then according to the duration of storage each group was subdivided into two equal groups one of them stored for one day and the other was stored for one month, then each group was further subdivided into two equal subgroups with (12) disks each one bonded with ligh
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