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Article
The Ovalisation of Steel Circular Hollow Sections under Bending

Authors: Amer M. Ibrahim عامر محمد ابراهيم --- Manahel Sh. Khalaf
Journal: DIYALA JOURNAL OF ENGINEERING SCIENCES مجلة ديالى للعلوم الهندسية ISSN: 19998716/26166909 Year: 2018 Volume: 11 Issue: 1 Pages: 12-19
Publisher: Diyala University جامعة ديالى

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Abstract

This paper investigates the ovalisation behavior of the Steel Circular Hollow Sections (CHSs) when subjected to bending moment. The experimental program included testing of ten specimens in four groups in order to examine the influence of changing the diameter, thickness, length and the presence of openings on the ovalisation phenomenon of these specimens.The experimental results showed that the ovalisation of the specimen cross-section appears clearly when the diameter to thickness ratio (D/t) is ranging from 17 to 50, while the ovalisation of the specimens that have D/t ratio greater than 50 is very little or unclear because the instability of these specimens are controlled by the local buckling. In addition, the change of the specimen length and the presence of openings didn’t cause the cross-section ovalisation.


Article
Influence of Concrete Strength on the Cycle Performance of Composite Steel Plate Shear Walls

Authors: Amer M. Ibrahim عامر محمد ابراهيم --- Huda M. Najem
Journal: DIYALA JOURNAL OF ENGINEERING SCIENCES مجلة ديالى للعلوم الهندسية ISSN: 19998716/26166909 Year: 2018 Volume: 11 Issue: 4 Pages: 1-7
Publisher: Diyala University جامعة ديالى

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Abstract

The goal behind this research is to highlight on structural system using composite steel plate shear wall, this approach is widely used in many countries, due to its desired features. Composite steel plate shear wall are often considered essential in design of building to resist seismic action. This paper discuss the effect of concrete strength on behavior of CSPW, for this objective one story one bay model with different compressive strength (25, 28 , 45, 50, 55, 65)MPa ,this model formed by finite element code which is advanced by university of Amirkabir. The accuracy of the representation of the model by numerical analysis, numerical result contrast with valid experiment which explain suitable agreement. Result show increasing the compressive strength would advance the cycle behavior. By contrast the result in elastic region, it was seen initial stiffness is not enhance by varying the compressive strength.


Article
Study the Response of Bubbled Wide Reinforced Concrete Beams with Different Shear Steel Plate Spacing

Authors: Amer M. Ibrahim عامر محمد ابراهيم --- Mohammed J. Hamood --- Ahmed A. Mansor احمد عبد الله منصور
Journal: DIYALA JOURNAL OF ENGINEERING SCIENCES مجلة ديالى للعلوم الهندسية ISSN: 19998716/26166909 Year: 2018 Volume: 11 Issue: 2 Pages: 1-13
Publisher: Diyala University جامعة ديالى

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Abstract

This paper presents an experimental investigation on the behavior of bubbled wide reinforced concrete beams with different shear steel plate spacing. Four specimens with the dimensions of 215x560x1800mm are investigated. The variables studied in this work is using the 10mm stirrups with 125mm spacing and 3mm thickness steel plate with spacing 125, 166 and 250mm instead of reinforcing stirrups. Shear steel plates is good alternative for replacing the stirrups and gives increasing in yield and ultimate loads with 17% and 18% respectively and decreasing the deflection by 8% at yield and 12% at ultimate. Moreover decrease the strain in longitudinal reinforcement by 8% at yield and 24% at ultimate, and reduced the total weight by 2.7%. By increasing the spacing of shear steel plate by 33% and 100%, the results showed that the yield load reduced to 3% and 4% respectively, but the deflection was increased with 37% and 20% (at yield). The strain in interior legs is more than the strain in exterior legs by 189%, 142% and 52% at yield for spacing 125, 166 and 250mm respectively. ACI 318-14 [1] and EC 2 [2] codes give a predicted deflection more than the experimental deflection by 26% and 30% on average respectively.


Article
USE OF BACTERIA TO SELF-HEALING CONCRETE CRACKS
استخدام البكتريا في معالجة التشققات في الكونكريت

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Abstract

The aim of the study was to using of bacteria to self-healing of cracks in concrete, and this study was the first of its kind in Iraq. This study used bacteria Bacillus Subtilis isolated from agricultural soils and dry soil, and has the cultivation and development in the selective medium SR-20, underwent tests, biochemical and diagnose bacteria and according to the (Bergys Manual & Medical Bacteria), where conducted laboratory tests preliminary to know the ability of these bacteria to address cracks concrete in terms of their ability to withstand factors existing in the form of concrete, including the pH baseband through development in the selective medium SR-20 with a pH baseband (PH=10), and tolerance of salinity when planted in the precipitation medium SM-7 containing chloride Calcium, also was testing Preparation Material treat cracks for the deposition of calcium carbonate crystals.The results also showed that the best way to prepare material treat cracks concrete to precipitate calcium carbonate are using the method consisting of silica + bacteria concentration (15×10), where results showed test ultrasound acoustic difference in the time it takes the wave to pass through cracks treatment in the experience of substance treatment consisting of silica + HCl + bacteria concentration (15 × 10), and the time it takes the wave to pass through the cracks of treatment in the experience of substance treatment consisting of silica + bacteria concentration (15 × 10), where results showed that Article therapy were completely rigid in the last test. The test results also showed scanning electron microscopic examination (SEM) create calcium carbonate to treat cracks material consisting of silica + bacteria.

ان الهدف من هذه الدراسة هو المعالجة الذاتية لشقوق الخرسانة باستخدام البكتريا، وتعتبر هذه الدراسة هي الاولى من نوعها في العـــــراق. استخدمت في هذه الدراسة بكتريا Bacillus Subtilis المعزولة من التربة الزراعية والتربة الجافة، وتمت عملية زراعتها وتنميتها في الوسط الانتقائي SR-20، اجريت الاختبارات الكيموحيوية وتشخيص البكتريا وفقا لما ورد فيBergys Manual &Medical Bacteria))، حيث اجريت الاختبارات المختبرية الاولية لمعرفة قدرة هذه البكتريا على معالجة التشققات الخرسانية من حيث قدرتها على تحمل العوامل الموجودة في قالب الخرسانة ومنها الاس الهيدروجيني القاعدي وذلك من خلال تنميتها في الوسط الانتقائي SR-20 ذو الاس الهيدروجيني القاعدي pH=10))، وتحملها للملوحة عند زراعتها في وسط الترسيب SM-7 المحتوي على كلوريد الكالسيوم، ايضا تم اجراء اختبارات تحضير مادة علاج الشقوق من اجل ترسيب بلورات كاربونات الكالسيوم. اظهرت نتائج اختبار الموجات الفوق الصوتية الاختلاف في الوقت الذي تستغرقه الموجة للمرور عبر الشقوق غير المعالجة والوقت الذي تستغرقه الموجة للشقوق المعالجة، حيث اظهرت النتائج ان مادة علاج الشقوق المكونة من السيليكا + معلق بكتيري كانت متصلبة بشكل كامل وحدوث نقصان في وقت انتقال الموجة الصوتية عبر الشقوق المعالجة.اظهرت نتائج البحث انه كلما كان عمق الشق وعرضه صغير كانت عملية المعالجة افضل، حيث ان عملية المعالجة كانت افضل في النماذج الخرسانية ذات عرض شق (1ملم) مقارنة للنماذج ذات العرض (2ملم)، اما من ناحية العمق فقد اظهرت النتائج ان عملية المعالجة كانت افضل لعمق شق (10ملم) مقارنة للنماذج ذات العمق (20ملم) و (30ملم). كما اظهرت نتائج اختبار الفحص بالمجهر الالكتروني الماسح SEM)) تكون كاربونات الكالسيوم لمادة علاج الشقوق المكونة من السيليكا + بكتريا.

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