A ‘locking-bolt’ demountable shear connector (LBDSC) is proposed to facilitate the deconstruction and reuse of steel-concrete composite structures, in line with achieving a more sustainable construction design paradigm. The LBDSC is comprised of a grout-filled steel tube and a geometrically compatible partially threaded bolt. The latter has a geometry that ‘locks’ the bolt in compatible holes predrilled on the steel flange and eliminates initial slip and construction tolerance issues. The structural behaviour of the LBDSC is evaluated through nine pushout tests using a horizontal test setup. The effects of the tube thickness, strength of concrete slab, and strength of infilled grout on the shear resistance, initial stiffness, and ductility of the LBDSC are assessed. The experimental results show that the LBDSC can achieve higher shear resistance and similar initial stiffness as compared to traditional welded studs. In addition, all tested LBDSCs exhibited slip capacities ranging from 14 to 32 mm and can be classified as ductile shear connectors according to Eurocode 4. A detailed finite element model was also created and found to be reliable to reproduce the experimental behaviour. Parametric studies were subsequently conducted using the validated model to study further parameters and generalise the experimental results. Due to the specific test setup, non-negligible uplift forces were generated in the connector and the potential implications are discussed.
In The Name of Allah Most Gracious Most Merciful
It is no secret to everyone that the endowment is an important nucleus for the prosperity of Islamic civilization, especially in the fields of education, health, economy, and defensive military actions that fall within the door of jihad, and so on. Al-Ashraf, Qom Al-Quds, Cairo, and other parts of the Islamic world. What we will see in the research.
Through an experimental program of eighteen specimens presented in this paper, the bond strength between reinforcing bar and rubberized concrete was produced by adding waste tire rubber instead of natural aggregate. The fine and coarse aggregate was replaced in 0%, 25%, and 50% with the small pieces of a waste tire. Natural aggregate replacement ratio, rebar size, embedded rebar length, the rebar yield stress of rebar, cover, and concrete compressive strength were studied in this investigation. Ultimate bond stress, bond stress-slip response, and failure modes were presented. The experimental results reported that a reduction of 19% in bond strength was noticed in 50% replaced rubberized concrete compared with convention
... Show MoreAn extensive program of laboratory testing was conducted on ring footing rested on gypseous soil brought from the north of Iraq (Salah El-Deen governorate) with a gypsum content of 59%. There are limited researches available, and even fewer have been done experimentally to understand how to ring footings behave; almost all the previous works only concern the behavior of ring footing under vertical loads, Moreover, relatively few studies have examined the impact of eccentric load and inclined load on such footing. In this study, a series of tests, including dry and wet tests, were carried out using a steel container (600×600×600) mm, metal ring footing (100 mm outer diameter and 40 mm inner diameter) was placed in the m
... Show MoreThis study focuses on CFD analysis in the field of the shell and double concentric tube heat exchanger. A commercial CFD package was used to resolve the flow and temperature fields inside the shell and tubes of the heat exchanger used. Simulations by CFD are performed for the single shell and double concentric tube.
This heat exchanger included 16 tubes and 20 baffles. The shell had a length of 1.18 m and its diameter was 220 mm. Solid Works 2014, ANSYS 15.0 software was used to analyze the fields of flow and temperature inside the shell and the tubes. The RNG k-ε model was used and it provided good results. Coarse and fine meshes were investigated, showing that aspect ratio has no significant effect. 14 million
... Show MoreObjective: To evaluate biomarkers of insulin resistance and acute phase reactants in obese, overweight and lean subjects and investigate the associations among those biomarkers. Methodology: This cross sectional study included 158 subjects who were stratified into three groups. Group1 comprised 53 obese patients (BMI≥ 30 kg/m2); group 2 were 54 overweight subjects, and group 3 had 51 healthy lean (BMI
Background: Insulin resistance (IR) is the primary metabolic disorder associated with obesity. Obesity is a growing worldwide health problem affecting both adults and children. Objectives: To determine the association between leptin and IR, and to identify the ratio of fasting glucose/leptin (G/L) and insulin/leptin (I/L) as a new simple method for the detection of IR in obese children.Methods: This study was done in the National DiabeticCenter/ AL-Mustansiriya University during the period fromMay 2013 until the end of October 2013. Fasting bloodglucose (FBG), serum insulin, leptin, and lipid profile weremeasured in 52 obese children (24 children with IR and 28without IR); their age range was (5-15) years, they werecompared with 38 healt
... Show MoreThe research aims to identify the concept of financing structure and what are the determinants that affect it and the goals achieved by financing in commercial banks in addition to the sources upon which the financing structure depends consisting of internal financing sources and external financing sources and their connection to the profits of commercial banks. Baghdad, Khaleeji Commercial Bank) registered in the Iraq Stock Exchange during the period for the years (2011-2020) published in the Iraq Stock Exchange from and the research relied on financial analysis tools to analyze the independent variable the following financing structure (the ratio of equity to total assets, the ratio of deposits to Total liabilities, the ratio of loans
... Show MoreThe objective of the study was to identify the effectiveness of a training program based on the employment of the educational portal in the development of the skills of the administrative body in the basic education schools in Dhofar Governorate. To achieve the goal, a training program was designed that includes the skills of the educational portal to be met by the administrative body and measuring its effectiveness. A questionnaire to identify training needs, and a notecard to evaluate performance. The study sample consisted of (70) individuals of the administrative staff. The researchers used the descriptive-analytical method to identify the training needs, design and build the training program and the experimental method for applying
... Show MoreThe importance of physical and nonphysical architectural design values made architectural designers need good experience to be experts of architectural values reasonably without neglecting any value in the design process. The importance of such values made that ignoring any values and mistakes occurs in the design process. Simultaneously, architectural designers' different nature and the difference in their experiences are causing different understandings of the design values, thus causing architectural mistakes. The research problem appears from the randomly propagating of mistakes in contemporary architecture, which is about to become a phenomenon in Al Sulaymaniyah city. The research aims to find the main reason
... Show MoreObjective: This study aimed to assessing new suggested technique of Physical Growth Curves (PGC) charts in
children under two years old of a non-probability sample.
Methodology: A non-probability sample of size (420) children under two years selected from 12 Primary
Health Care Centers in Diyala governorate during the period from 15th Nov. 2010 to 13th Mar. 2011
according to admix of a different properties together in one chart/or growth curve chart included in at least
weight, Height, and Head circumference.
Results: the results showed different properties that can be admix together in one chart/or growth curve
chart included in at least weight, Height, and Head circumference. And to overtake the problem of the norm