research centers


Search results: Found 6

Listing 1 - 6 of 6
Sort by

Article
OPTIMAL DESIGN OF PRESTRESSED CONCRETE HOLLOW CORE SLAB PANELS
التصميم الامثل لالواح البلاطات الخرسانية المسبقة الجهد المجوفة

Authors: Abdul Ridha Saleh عبـد الرضـا صالـح الفـتلاوي --- Muaid Adnan Abid Shahatha مؤيـد عدنـان عبد شحاثة
Journal: KUFA JOURNAL OF ENGINEERING مجلة الكوفة الهندسية ISSN: 25230018 Year: 2013 Volume: 5 Issue: 1 Pages: 33-50
Publisher: University of Kufa جامعة الكوفة

Loading...
Loading...
Abstract

The research has prepared programmed mathematical techniques by Visual basic language for analysis, design and calculating the optimization of precast prestress hollow core slab panels. The research deals with the optimization by adopting the modified Hooke-Jeevs method which is considered as a very suitable method especially for problems have many constraints. The formalizing of objective function was discussed according to required purpose. The aim of the study is to discuss three parameters (optimum weight, optimum cost and optimum live load). It is found that the average void percentage ratio regarding the optimum weight is about (50%) whereby the section tends to be in a shape where the voids become less than thickness and width take into consideration that the section is subjected to all the constraints (voids percentage tends to be much more than the regular case), as well as, it is found that the average of void percentage ratio concerning with the optimum cost is about (41%). The research also adopted preparing designable tables which are informative and easy in use practically for different kind of hollow core slab sections, it is found from the prepared maximum live load tables that the deflection restricts the span length not less than (60%), furthermore that adding topping slab (5cm) thickness increase the span length about (16-20) % for thicknesses (15-22) cm.

تناول البحث استخدام تقنيات رياضية برمجية بلغة فيجوال بيسك لتحليل وتصميم وحساب الامثلية لمقاطع البلاطات المجوفة المسبقة الصب المسبقة الجهد حيث تعرض البحث لدراسة الامثلية متبنيا الطريقة المعدلة لهوك- جيفس Hooke-Jeevs والتي تعتبر من الطرق المناسبة للمسائل المعرضة الى عدد كبير من المحددات او المقيدات. تم صياغة دالة الهدف بناءا على الغرض المطلوب حيث تم مناقشة تاثير ثلاثة عناصر و هي (الوزن الامثل ، الكلفة المثلى ، الحمل الحي الامثل ). وتبين بان معدل نسبة حجم الفراغات (Voids) بالنسبة لمقاطع الوزن الامثل هي تقريبا (50%) حيث يميل المقطع ليكون بالشكل الذي تكون الفراغات مستنفذه اكبر مسافة من عرض وارتفاع المقطع مع الاخذ بنظر الاعتبار خضوع المقطع لجميع المقيدات (نسبة الفراغات تميل لتكون اكبر بكثير من الحالة الاعتيادية) ، ومن جهة اخرى اظهرت الدراسة بان معدل نسبة حجم الفراغات (Voids) بالنسبة لمقاطع الكلفة المثلى هي تقريبا (41%). البحث تبنى ايضا اعداد جداول تصميمية سهلة الاستخدام عمليا لمختلف انواع المقاطع حيث وجد عند اعداد جداول الاحمال الحية بان الانحناء (Deflection) يقيد من طول الفضاء بما لا يقل عن (60%) وان اضافة طبقة خرسانية (Topping slab) بسمك (5 سم) يزيد من امكانية زيادة طول الفضاء بمقدار (16- 20)% لسمك يتراوح بين (15-22) سم.


Article
Using TermoDeck System for Pre-Cooling/ Heating to Control the Building Inside Conditions
إستخدام نظام الترمودَك للتبريد/ التسخين الأوّلي للسّيطرة على الظروف الداخلية للبناية

Loading...
Loading...
Abstract

In this paper, experimental study has been done for temperature distribution in space conditioned with Ventilation Hollow Core Slab (TermoDeck) system. The experiments were carried out on a model room with dimensions of (1m ×1.2m ×1m) that was built according to a suitable scale factor of (1/4). The temperature distributions was measured by 59 thermocouples fixed in several locations in the test room. Two cases were considered in this work, the first one during unoccupied period at night time (without external load) and the other at day period with external load of 800W/m2 according to solar heat gain calculations during summer season in Iraq. All results confirm the use of TermoDeck system for ventilation and cooling/heating purposes in arid and hot climate for its ease, simple and good comfort performance and to save energy and improve the overall energy performance of the building by reducing the peak load.

تم في هذا البحث اجراء دراسة عملية لتوزيع درجات الحرارة في حيّز مكيَّف بنظام تهوية البلاطة المجوفة (ترموديك). أُجريَت التجارب على انموذج مصغّر لغرفة بأبعاد (1m1.2m1m)، والذي بُنِيَ على أساس مقياس رسم مناسب هو (14). تم قياس توزيع درجات الحرارة بوساطة تثبيت (59) مزدوجاً حراريا في مناطق و مقاطع متعددة. أُخذت حالتان في هذا العمل صُنِّفت على اساس عدم انشغال الحيز أي خلال فترة الليل (دون وجود حمل خارجي) والاخرى خلال فترة النهار أي بوجود حمل خارجي مقداره (800W/m2) وفقا لحسابات الكسب الحراري الشمسي الناتج من الاشعاع الشمسي خلال فصل الصيف في العراق .جميع النتائج أكّدت إستخدام نظام الترموديك لأغراض التهوية والتبريد/التسخين في أجواء الاقاليم الجافة لبساطتها واداءها الجيد من حيث الراحة الحرارية وخزنها للطاقة و تحسين اداء الطاقة الكليّة للبنايةعن طريق تقليل الحمل الاعظم.


Article
EXPERIMENTAL INVESTIGATION FOR THE BEHAVIOR OF ORDINARY REINFORCED HYBRID CONCRETE HOLLOW CORE SLAB

Authors: Ammar Y. Ali --- Labeeb S. Al-Yassri --- Mohammed M. AL-Khafaji
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2017 Volume: 10 Issue: 2 Pages: 214-225
Publisher: Al-Qadisiyah University جامعة القادسية

Loading...
Loading...
Abstract

This paper presents an experimental study to investigate the effect of hybrid strength concrete (two types of concrete, 25 MPa and 70 MPa) on the behavior of one-way hollow core concrete slab ordinary reinforced with steel rebars. The hybrid HCSs showed an enhancement in shear strength capacity, cracking load and ductility as compared with to HCS with normal strength concrete (25 MPa). The increase in shear strength capacity and cracking load were about (16%) and (29%) respectively higher than normal strength hollow core slab. Also, from experimental results, the crack width of hybrid HCS was narrower than that for normal strength slab at all stages of loading. At service load stage, the width of crack was narrower than normal strength slab by about (10-31%). The failure mode still brittle diagonal shear failure.


Article
EXPERIMENTAL INVESTIGATION FOR THE BEHAVIOR OF HOLLOW CORE CONCRETE SLAB REINFORCED WITH HYBRID REINFORCEMENT

Authors: Labeeb S. Al-Yassri --- Ammar Y. Ali --- Mohammed M. AL-Khafaji
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2017 Volume: 10 Issue: 3 Pages: 308-317
Publisher: Al-Qadisiyah University جامعة القادسية

Loading...
Loading...
Abstract

This paper provides an experimental study to investigate the effect of hybrid reinforcement on the behavior of hollow core slab casted with NSC. Experimental results showed that using of hybrid reinforcement (CFRP and steel bars) as internal reinforcement give better results of ductility compared with HCS reinforced with CFRP bars only. On the other hand, using of CFRP bars as an internal reinforcement have slightly effect on the shear strength capacity of hollow core slab. On the other hand, CFRP reinforcement lead to decrease the stiffness of slab at post cracking stage; therefore, deflection will increase at the same load after cracking.


Article
Assessment the Shear Behavior of Sustainable Thick Hollow Core Slab Using Experimental and Nonlinear Finite Element Modelling

Authors: Yousif Nassif Sabr --- Dr. Husain Khalaf Jarallah --- Dr. Husain Khalaf Jarallah
Journal: Anbar Journal of Engineering Sciences مجلة الأنبار للعلوم الهندسية ISSN: 19979428 Year: 2019 Volume: 8 Issue: 1 Pages: 35-43
Publisher: University of Anbar جامعة الانبار

Loading...
Loading...
Abstract

This investigation provides experimental results and nonlinear analysis by using finite element model of thick hollow core slab made from recycled lightweight material. Four hollow core slabs specimens were cast and tested in this investigation with dimensions (1200mm length, 450mm width and 250mm thickness). The crushed clay brick was used as a coarse aggregate instead of gravel. The iron powder waste and silica fume were used in order to increase the compressive strength of concrete. The techniques reduction hollow length and use shear reinforcement were used to improve shear strength and avoid shear failure. The specimens were tested by applying two-line load up to failure. The experimental results were showed these techniques were resisted the shear failure significantly and works to change failure mode from shear to flexural failure. Finite element computer software program (ANSYS) was used to analysis hollow core slabs specimens and compare the experimental results with the theoretical results. Good agreement have been obtained between experimental and numerical results.


Article
IMPROVING SHEAR STRENGTH OF THICK HOLLOW CORE SLABS BY USING LIGHTWEIGHT HIGH STRENGTH CONCRETE PRODUCED FROM RECYCLED CRUSHED CLAY BRICK AND IRON POWDER WASTE

Authors: Yousif Nassif Sabr --- Husain Khalaf Jarallah --- Hassan Issa AbdulKareem
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2019 Volume: 23 Issue: 6 Pages: 128-146
Publisher: Al-Mustansyriah University الجامعة المستنصرية

Loading...
Loading...
Abstract

This investigation provides an experimental study about structural behavior of reinforced hollow core slab (HCS) by using recycled lightweight material. Six hollow core slab specimens were casted with dimensions 1200mm length, 450mm width and different thickness (200mm, 250mm and 325mm). The shear reinforcement was used for each thickness to resist the shear failure that occur in thick hollow core slab. The Recycled materials were crushed clay brick and iron powder waste. The crushed clay brick was used as a coarse aggregate instead of gravel to a get lightweight concrete. The hollow core slab specimens were tested with age 28-day. The test was done by applied two line load up to failure. The experimental results showed an increase in the shear strength up to 50% and decrease in the maximum deflection up to 50% with increasing thickness specimen. Also the experimental results showed an increase in the shear strength up to 50% and increase in the maximum deflection up to 50% with using shear reinforcement compare with hollow core slab specimens without shear reinforcement. From the experimental results of this investigation can be avoid the shear failure and change the mode of failure from the shear to flexural failure.

Listing 1 - 6 of 6
Sort by
Narrow your search

Resource type

article (6)


Language

English (4)

Arabic and English (1)


Year
From To Submit

2019 (2)

2017 (2)

2014 (1)

2013 (1)