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Article
Ductility Improvement of R.C Beams with Large Web opening by using Reactive Powder Concrete Layers

Authors: Husain Khalaf Jarallah --- Nidaa Qassim Jassim
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2018 Volume: 25 Issue: 3 Pages: 30-39
Publisher: Tikrit University جامعة تكريت

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Abstract

In this investigation the effect of large web opening on the on the behaver of beams made by normal concrete (NC) and reactive powder concrete (RPC) have been studied. The experimental work consists of casting and testing in flexure 12 rectangular simply supported reinforced concrete beams. The main parameters of this test are opening locations and normal concrete and RPC location with is the section. The ultimate loads, cracking loads, load -deflection behavior, skew of the openings (deflection at the two opposite corners of openings) and ductility were discussed. These results showed that increase ultimate loads (Pu) and stiffness by increase RPC layers. The using RPC layers increase ultimate load about (1-30) %. Using RPC in compression fiber is found to be more effective than using RPC in tension fiber. The cracking load of hybrid beam with one layer of RPC in compression fiber (having one opening) higher than NC beams by 48.5%. The ultimate strength was decreases with increases opening about (4-21)%, thus indicating that the stiffness decreases accordingly. Hybrid beams with RPC in tension fiber failed with less crack than those for hybrid beams with RPC in compression fiber at the same number of openings. The skew at opening of flexural zone show greater values than the skew at opening in shear zone for each beam until failure. The increase in the number of openings leads to increase in the ductility because it reduces the strength of beams.


Article
Finite Element Analysis of Reinforced Concrete T-Beams with Multiple Web Openings under Impact Loading
التحليل بإستخدام العناصر المحدده لعتبات خرسانيه مسلحه ذات مقطع (T) حاويه على فتحات وتره متعدده تحت تأثير الحمل الصدمي

Authors: Nazar Kamel Oukaili نزار كامل العقيلي --- Abeer Hussein Al-Shammari عبير حسين الشمري
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2014 Volume: 20 Issue: 6 Pages: 15-27
Publisher: Baghdad University جامعة بغداد

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Abstract

In this study, a three-dimensional finite element analysis using ANSYS 12.1 program had been employed to simulate simply supported reinforced concrete (RC) T-beams with multiple web circular openings subjected to an impact loading. Three design parameters were considered, including size, location and number of the web openings. Twelve models of simply supported RC T-beams were subjected to one point of transient (impact) loading at mid span. Beams were simulated and analysis results were obtained in terms of mid span deflection-time histories and compared with the results of the solid reference one. The maximum mid span deflection is an important index for evaluating damage levels of the RC beams subjected to impact loading. Three experimental T-beams were considered in this study for calibration of the program. All models had an identical cross-section and span similar to those of the experimental beams. The diameter of the openings of the experimental beams was 110 mm. Three other diameters were varied (50, 80 and 130) mm. The location of the face of the opening with respect to the location of impact loading was investigated (the face of the opening at distance varied 0d, 0.5d, 1d and 1.5d from the location of loading, where d is the effective depth) and the number of web openings was varied (2,4 and 6) openings. All modeled beams subjected to dropping mass of 24.5 kg with height of drop of 250 mm (as for the experimental beams). Results obtained from this study showed that the behavior of beams with circular openings of diameter equal to 22% the web depth has a small effect on the response of the RC T-beams. On the other hand, introducing circular openings with a diameter equal to 35% and 57% of the web depth (80 and 130 mm) increases the maximum mid span deflection by 23% and 43% respectively. Results also showed that, openings with a distance greater than or equal to 1.5 d from the location of impact loading have no effect on the deflection of the RC beams.

في هذه الدراسه تم عمل تحليل ثلاثي الأبعاد بإستخدام طريقة العناصر المحدده عن طريق البرنامج التحليلي ANSYS وذلك لتمثيل عتبات خرسانيه مسلحه ذات مقطع (T) تحتوي على فتحات وتره متعدده دائريه الشكل خاضعه لحمل صدمي. تم إعتماد ثلاث متغيرات تصميميه تضم: حجم وموقع و عدد الفتحات. تم تسليط الحمل الصدمي على 12 نموذج من العتبات الخرسانيه المسلحه بسيطة الإسناد في نقطه واحده تقع منتصف الفضاء. النتائج التي تم الحصول عليها والتي هي بدلالة مخططات هطول منتصف الفضاء مع الزمن تم مقارنتها مع نتائج النموذج المرجعي الغير حاوي على فتحات حيث إن الهطول الأقصى هو مؤشر مهم لتحديد مستوى الضرر للعتبات الخاضعه للحمل الصدمي. تم اعتماد نتائج ثلاث عتبات مفحوصه عمليا من أجل معايرة البرنامج. جميع النماذج لها مقطع وفضاء مماثل للعتبات المفحوصه عمليا. قطر فتحات العتبات المفحوصه عمليا يساوي 110ملم. ثلاثة أقطار أخرى تم دراستها (50، 80، 130 ملم) وكذلك تم دراسة موقع الفتحات نسبة الى موقع الحمل الصدمي (بداية الفتحه تتغير بمسافة 0d، 0.5d، 1d، 1.5d من موقع الحمل) وكذلك عدد الفتحات متغير (2، 4، 6 فتحات). النتائج المستحصله بينت أن العتبات ذات فتحات دائريه بقطر 22% من عمق الوتره لها تأثير قليل على هطولها. من ناحيه أخرى فإن عمل فتحات دائريه بقطر 35% و 57% من عمق الوتره يزيد من الهطول الأقصى لمنتصف الفضاء بنسبة 23% و 43% على التوالي. كذلك بينت النتائج بأن الفتحات ذات مسافه اكبر أو تساوي 1.5d من موقع الحمل الصدمي ليس لها تأثير على هطول العتبات الحاويه على تلك الفتحات.

Keywords

beams --- web openings --- impact loading


Article
CONTRIBUTION TO THE U-TURN DESIGN AT MEDIAN OPENINGS IN IRAQ: Al-NAJAF CITY AS A CASE STUDY
المساهمة في تصميم الاستدارات نوع U في العراق : مدينة النجف كحالة دراسية

Author: Hamid Athab Eedan Al-Jameel حامد عذاب عيدان ال جميل
Journal: KUFA JOURNAL OF ENGINEERING مجلة الكوفة الهندسية ISSN: 25230018 Year: 2014 Volume: 6 Issue: 1 Pages: 117-132
Publisher: University of Kufa جامعة الكوفة

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Abstract

Field observations indicate that left turning vehicles at U-turn sections lead to a significantly bottleneck (congestion) at both origin and destination (opposing) roads. The bottlenecks have been observed in several U-turns such as Kufa –Najaf U-turn sections, Najaf –Karbala U-turn sections. It was found that left turn flow from U-turn leads to high congestion on both origin and destination roads. Therefore, field improvements have been done by the traffic policemen who create a temporary barrier from traffic plastic signs in order to protect left turning vehicles from through traffic in opposing direction. This study introduces new design for U-turn in order to protect both turning and through traffic to increase the level of performance. This design has been tested by using simulation model. The developed model (S-Paramics) has been calibrated using field data collected from Al-Najaf city. Then, the validation for the developed model has been implemented using another set of field data. Finally, the simulation model has been adopted to test the new design for U-turn. It was found that the new design gives higher capacity than the current design.

بينت المشاهدات الموقعية بان المركبات المستديره يسارا في مقطع الاستداره (U-turn) تقود الى اختناقات مفاجئه للطريق المنطلقة منه الرحله وللطريق بالاتجاه المعاكس. الاختناقات المروريه قد شوهدت في العديد من الاستدارات على طريق نجف-كربلاء وطريق كوفه-نجف. لقد وجد بان المركبات المستديرة يسارا تؤدي الى ازدحام عالي على كلا الطريقين المنطلقة منه المركبات والذاهبه اليه. لذلك اجريت تحسينات من قبل شرطة المرور وذلك من خلال وضع سياج مؤقت من العلامات المروريه البلاستيكيه لحماية المركبات المستديره من المرور بالاتجاه المعاكس. الدراسة الحاليه تقدم تصميم جديد للاستدارات لحماية المركبات المستديرة من المرور الاخر ولزيادة مستوى الاداء. هذا التصميم تم فحصه باستخدام نموذج المحاكاة. لقد تم معايرة البرنامج الحالي باستخدام بيانات حقلية تم جمعها خلال هذه الدراسة من مدينة النجف. التأكد من تمثيل النموذج لواقع الحال تم باستخدام بيانات حقلية اخرى. ثم بعد ذلك تم اعتماد النموذج المطور لدراسة التصميم الجديد حيث وجد انه يمثل افضل من التصميم السائد في زيادة مقدارة السعة للاستدارة.


Article
Impact Analysis of Reinforced Concrete Columns with Side Openings Subjected to Eccentric Axial Loads
التحليل الصدمي لأعمدة خرسانيه مسلحة حاوية على فتحات جانبيه ومعرضة لأحمال محورية لا مركزية

Authors: Nazar Kamil Ali أ.د. نزار كامل علي --- Ali Ihsan Salahaldin علي احسان صلاح الدين --- Ahmed Jabbar Hamza أحمد جبار حمزة
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2015 Volume: 21 Issue: 2 Pages: 1-19
Publisher: Baghdad University جامعة بغداد

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Abstract

In this research the behavior of reinforced concrete columns with large side openings under impact loads was studied. The overall cross sectional dimensions of the column specimens used in this research were (500*1400) mm with total height of (14000) mm. The dimensions of side openings were (600*2000) mm. The column was reinforced with (20) mm diameter in longitudinal direction, while (12) mm ties were used in the transverse direction. The effect of eccentric impact loads on the horizontal and vertical displacement for this column was studied. Nonlinear finite element analysis has been carried out using ready computer finite element package (ANSYS) to simulate the behavior of the reinforced concrete column with large side openings. Two load cases were considered in this investigation (C1, C2) with three different load values for each case. In the first case (C1) the loads was applied to one side of the column and in the second case (C2) the loads was applied to both sides. An Equilateral triangular load-time function was used for simulation the impact load results from gantry cranes supported by the column with total time duration (0.1 sec).In order to verify the analysis method, as no experimental data exist for comparing the obtained results, another analysis is made for tested conventional column under impact load at mid-height and good agreement has been obtained.For the above mentioned column, the maximum displacements were (33.3, 22.2) mm in the horizontal and longitudinal direction respectively, location of the maximum horizontal displacement was at the crown of the column. By comparing the results of the first loading case with the second one it is shown that in the horizontal direction, maximum displacement increases by (139%), (208%), and (147%) respectively, also the maximum vertical displacement increases by (150%), (172%), and (172%) respectively.

في هذا البحث تم دراسة سلوك عمود خرساني يحتوي على فتحات جانبية كبيرة (عمود ذو جزئين) تحت تأثير احمال صدمية لامركزية, حيث تم اعتماد عمود ذو مقطع (500*1400) ملم وبأرتفاع (14000) ملم ويحتوي على فتحات جانبية كبيرة بأبعاد (2000*600) ملم وتم تسليح العمود بأستخدام حديد بقطر 20 ملم في الاتجاة الشاقولي وقطر 12 ملم في الاتجاه العرضي .وتم دراسة تأثير تغير مقدار التحميل على الازاحه لهذا العمود.تم اعتماد التحليل اللاخطي بأستخدام طريقة العناصر المحدده وبالاستعانه ببرنامج (ANSYS) ليُحاكي تصرف العمود المحتوي على فتحات جانبيه وتم تسليط الاحمال بحالتين وكل حالة تحتوي على ثلاث قيم مختلفة للحمل ,حيث في الحالة الاولى تم التحميل من جانب واحد وفي الحالة الثانيه تم التحميل من جانبين, , وتم استخدام دالة حمل مثلثة الشكل متساوية الساقين لتمثيل الحمل الصدمي المسلط خلال فترة تحميل تبلغ (0.1) ثانيه.اكبر ازاحه تم الحصول عليها كانت (33.3) ملم مع المحور (X) و (22.2) ملم مع المحور (Y), وأن موقع اكبر ازاحه افقيه كان عند قمة العمود. وعند مقارنة النتائج لحالتي التحميل (التحميل من جانب واحد والتحميل من الجانبين) تبين ان نسبه الزياده في الازاحه الافقيه هي (139%, 208% , 147% )على التوالي, في حين ان نسبه الزياده في الازاحه العموديه هي (150%, 172%, 172%) على التوالي .


Article
Shear Lag in Reinforced Concrete T-Beams with Web Openings

Authors: Eyad Kadhum Sayhood --- Nisreen Saleh --- Ahmed S.Hanon
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 8 Part (A) Engineering Pages: 1673-1687
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this paper, an extensive study is carried out 18 beams on the behavior of T-beams (8 with web openings, 10 without openings). Compressive strains distribution at the flanged are investigated with the presence of the openings in web to recheck the effective width of flange with real flange width. Parametric study are considered in this paper includes the compressive strength, longitudinal flexuralreinforcement,flangereinforcement,shear reinforcement and theweb openings (location, shape, size). Generally, standard codes of practice have overestimated effective flange width due to concentrated load effect, and codes do not take into account the web openings effect. Based on the results, the enhancement in effective width for each parameter were 9.1%-13.36%(compressive strength),10.1%-13.3%(longitudinal flexural reinforcement),7.6%-18.2%(flange reinforcement),3.35%-5.7%(shear reinforcement), the web openings reduced the effective flange width by 15% (openings at mid span ) and 5% ( openings at quarter span ) and the circular opening gavean optimum effective width better than rectangular opening were located both at quarter span.


Article
Experimental and Numerical Investigation of High Strength Reinforced Concrete Deep Beams with Web Openings under Repeated Loading
التحقيقات التجريبية و العددية للعتبات الخرسانية المسلحة العميقة ذات الفتحات في وتراتها تحت تحميل المتكررة

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Abstract

This paper presents experimental investigations to study the behavior of High Strength Reinforced Concrete (HSRC) deep beams with web openings under monotonic and static repeated loading conditions. The experimental work procedure consisted of testing eighteen simply supported HSRC deep beams both with and without web openings. The numerical work procedure consisted of testing ten simply supported HSRC deep beams both with web openings. All beams had the same dimensions and flexural reinforcement. They had an overall length of 1400 mm, a width of 150 mm and a height of 400 mm. The investigated test parameters were concrete compressive strength, shape and size of openings, vertical and horizontal reinforcement ratios, shear span to effective depth ratio (a/d ratio) and loading history. The experimental results reveal that the ultimate load capacities for specimens tested under four different repeated loading regimes decrease in the range between 2% and 19% in regards to the control specimens which were tested under monotonic loading regime. The results indicated that the increase in the severity of loading history leads to a decrease in the ultimate shear strength of the deep beams and causes increases in their ductility ratio. The ultimate loads of HSRC deep beams with square web openings size of (50*50mm, 60*60mm and 70*70mm) tested under the repeated loading history (HS-1) which consisting of five phases decreased by (11.4 %, 24.1% and 26.3 %, respectively) compared to that of identical solid deep beam. The ultimate load of HSCR deep beam with circular web openings shape tested under repeated loading history (HS-1) increases by 8.6 % compared to the equivalent square web openings shape. For numerically analyzed beams under repeated loading history (HS-1), the ultimate load increases by 16% when using area of 2500mm2 of circular web openings shape (equal in area to square web opening size 50mm*50mm) and by 13.5% when using rhombus web openings shape of the dimensions 50*50mm in comparison with the case of 60-mm size square web openings.

يھدف ھذا البحث الى التحري التجريبي والتحليلي عن لدراسة سلوك العتبات الخرسانية المسلحة العميقة عالية المقاومة الحاوية على فتحات في وتراتھا المعرضة الى الأحمال التزايدية التكرارية باتجاه واحد. يتألف البرنامج العملي التجريبي من فحص ثمانية عشر من العتبات الحاوية وغيرالحاوية على فتحات في وتراتھا. كما كانت جميع النماذج ذات ابعاد (طول 1400 ملم, سماكة 150 ملم و ارتفاع 400 ملم). فحصت النماذج تحت تأثير ازاحة استاتيكية تزايدية تكرارية باتجاه واحد. اشتملت متغيرات البحث على مقاومة انضغاط الخرسانة و شكل وحجم الفتحات و نسبة حديد التسليح الشاقولي والافقي و نسبة فضاء القص الى الارتفاع الفعال للعتبة وانماط التحميل التكراريةأربعة انماط من التحميل المتكرر سلط على العتبات العميقة مستندة على نتائج فحص النموذج المتحكم. أظھرت النتائج التجريبية انخفاض التحمل الاقصى لھذه العتبات بنسب تتراوح بين 2% و %19 نسبة الى النموذج المفحوص تحت تحميل تزايدي بأتجاه واحد. ھذا يعني ان الزيادة في شدة نمط التحميل المتكرر تؤدي الى تقليل مقاومة القص للعتبات العميقة.


Article
Experimental Behavior of Hybrid Steel and Polypropylene Fiber Reinforced Concrete Deep Beam Containing Openings Abstract-Twelve simple span reinforced concrete deep beams were

Authors: Nabeel A. al-Bayati --- Noor A. Hadi
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 2 Part (A) Engineering Pages: 163-171
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Twelve simple span reinforced concrete deep beams were tested under symmetrically two points top load to examine the effect of steel fiber and polypropylene fiber and influence of the transverse circular openings on their behavior. The variables investigated involve beams with and without openings, the volume fraction of fibers, shear span to effective ratio a/d, and inclined reinforcement around the openings. All the beams had the same overall dimensions, flexural reinforcement and opening size. Many mixes have been used by combination between steel fibers and polypropylene fibers with different percentages of (1%SF-0%PPF), (0.75%SF-0.25%PPF), (0.5%SF-0.5%PPF), (0.25%SF-0.75%PPF), (0%SF-1%PPF) in addition to mix without fibers. The test results showed that fibers greatly increase the diagonal cracking strength and shear strength of reinforced concrete deep beams, where the variation of the type of concrete from normal concrete to hybrid concrete for deep beam contains openings led to increase the ultimate strength by about 30%. In addition, it was found that the shear capacity of deep beams increased when the shear-span/effective depth ratio decreased. The inclined reinforcement around the opening was observed to be very efficient in improving the ultimate load capacity and deflection response.


Article
FLEXURAL BEHAVIOR OF R.C. TWO-WAY SLABS WITH OPENING STRENGTHENED WITH CFRP SHEETS

Authors: Esraa Jassim Mohammad اسراء جاسم محمد --- Mazen Dewan Abdulla مازن ديوان عبد الله
Journal: Muthanna Journal of Engineering and Technology(MJET) مجلة المثنى للهندسة والتكنولوجيا ISSN: 25720317 25720325 Year: 2018 Volume: 6 Issue: 2 Pages: 200-209
Publisher: Al-Muthanna University جامعة المثنى

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Abstract

This paper present a study of the flexural behavior of reinforced concrete twoway slabs with opening strengthened by Carbon Fiber Reinforced polymersheets.The experimental work included testing 10 specimen two-way slabs with opening, which include 4 control specimens and 6 strengthened with CFRP sheets. The dimensions of the slab specimens are (800 × 800) mm, (70) mm depth and they were made of normal strength concrete. The reinforced concrete slabs containing a single eccentric and concentric opening strengthened by CFRP sheets, has been investigated, also the behavior of unstrengthened slabs and the slab without openings has been studied. These slabs were arranged in four groups and four layout of CFRP sheets has been considered. The slabs were tested with uniformly distributed loads and simple supports on the four edges. The results showed that the load-carrying capacities have been increased of the slabs with openings strengthened with CFRP sheets when compared with the slabs without strengthening.


Article
EFFECT OF WEB OPENING'S SHAPE ON THE BEHAVIOR OF HYBRID REINFORCED CONCRETE DEEP BEAMS UNDER REPEATED LOADING

Authors: Sawsan Akram Hassan --- Mohammed Kamil Ali
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2019 Volume: 23 Issue: 3 Pages: 128-141
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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This research aims to study experimentally behavior of hybrid deep beams with web openings when subjected to two points' monotonic and repeated loading in effect of web openings shape. All tested deep beams have the same flexural (0.0184) and web reinforcement (ρw=0.003) and same dimensions of (1500mm length, 150mm width and 350mm height). In this research, the idea of hybridity was achieved by reinforcing the two shear spans with steel fiber keeping the middle span free from this fiber. The aim was to strengthen shear region against shear failure (diagonal strut failure). To achieve the aim, six deep beams were cast and tested. Three of them were tested under monotonic loading as control beams to the other three beams tested under repeated loading at levels of 55% of the ultimate load of their control beams. The variables studied were: loading type (either monotonic or repeated) and web opening shapes. The results indicated that using different opening shapes (rectangular, circular or square) with an equivalent shape of 1.37% of beam size show that the ultimate load of beams with rectangular opening decreases by 10% as compared with beams with square web openings of the same area. Also, the ultimate load of beams with circular openings increases by 6.8% as compared with beams with square web openings of the same area. Also, it can be concluded that deep beams haves circular openings are increasing in ultimate loads by 17.5% as compared to rectangular web openings shapes with equivalent area.


Article
BEHAVIOR OF HYBRID REINFORCED CONCRETE DEEP BEAMS WITH WEB OPENINGS UNDER REPEATED LOADING

Authors: Sawsan Akram Hassan --- Mohammed Kamil Ali
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2019 Volume: 23 Issue: 4 Pages: 52-75
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

This research aims to study experimentally behavior of hybrid deep beams when subjected to two point's monotonic and repeated loading in presence or absence of web openings. All tested deep beams have the same reinforcement in flexural (ρ= 0.0184) and web (ρw=0.003) and same dimensions of (1500mm length, 150mm width and 350 mm height). In this research, the idea of hybridity was achieved by reinforcing the two shear spans with steel fiber keeping the middle span free from this fiber. The aim was to strengthen shear wings against shear failure (diagonal strut failure). To achieve the aim, twelve deep beams were cast and tested. Six of them were tested under monotonic loading as control beams to the other six beams tested under repeated loading at levels of 55% of the ultimate load of their control beams. The variables attempts were: loading type (either monotonic or repeated), beam type (either hybrid or non-hybrid), steel fiber (SF) ratio, and finally web opening sizes. The results illustrate that the ultimate load of deep beam with web openings under monotonic loading increases as the SF ratio increases. When SF was added to shear spans with a ratios of 1% and 2% under monotonic loading system, the ultimate load percentages increase are 37.5% and 68.75%, respectively compared with ultimate loads of beams which are without SF. Also, using fiberous concrete in casting the entire length of beams leads to an increase in the ultimate load of 4.55% as compared with deeps beams with the same SF ratio of 1%, and 43.75% as compared with beams cast with conventional concrete. The results using different opening size of square shapes, it was found that the ultimate load decrease as size of web openings increases from 0.61% of beam size to 1.37% of beam size by 10.17% and 25.42%, respectively as compared with hybrid deep beam without openings.

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