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A Contribution to Studying the Efficiency of Flexural Strengthening of RC Beams with Different Lengths of CFRP Strips by Using NSM Technique

مساهمة لدراسة فعالية تقوية الجيزان البيتونية المسلحة على الانحناء بأطوال مختلفة من شرائح ألياف البوليمر الكربونية باستخدام تقنية التقوية (NSM)

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 Publication date 2014
and research's language is العربية
 Created by Shamra Editor




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This research aims to study the efficiency of flexural strengthening of RC beams with different lengths of CFRP strips by using (NSM) technique. The study is carried out experimentally on (14) concrete beams; the variables considered are (the length and number of CFRP strips). This is established by dividing the work into two groups: the first one includes (6) beams strengthened by variable carbon fiber strip lengths and one strip, The second group includes (6) beams strengthened by variable carbon fiber strip lengths and two strips, as well as two control beams. The results indicate that carbon fibers have a noticeable effect on increasing the bearing capacity of (NSM) strengthened beams. The results also show that strengthening the beams by CFRP and not along the length of the beam and in one layer does not contribute to increasing beam strength, but when the number of layers increases, an increase in beam strength is noticed at a rate range (40%-72%).


Artificial intelligence review:
Research summary
يهدف هذا البحث إلى دراسة فعالية تقوية الجوائز البيتونية المسلحة على الانحناء باستخدام شرائح ألياف البوليمر الكربونية بتقنية التقوية بالرصح القريب من الوجه (NSM). تم إجراء الدراسة على 14 جائزاً بيتونياً مسلحاً، حيث تم تقسيم الجوائز إلى مجموعتين: الأولى تشمل 6 جوائز مقواة بطول مختلف من شرائح ألياف الكربون وبطبقة واحدة، والثانية تشمل 6 جوائز مقواة بطبقتين من شرائح ألياف الكربون وبأطوال مماثلة للمجموعة الأولى، بالإضافة إلى جائزين معياريين. أظهرت النتائج أن ألياف الكربون تزيد من تحمل الجوائز على الانحناء، وأن استخدام طبقة واحدة من الألياف على جزء من طول الجائز لا يساهم في زيادة التحمل بشكل كبير، بينما استخدام طبقتين يزيد من التحمل بنسبة تتراوح بين 40% و72%.
Critical review
دراسة نقدية: يعتبر هذا البحث خطوة مهمة في مجال تقوية المنشآت البيتونية المسلحة باستخدام ألياف البوليمر الكربونية. ومع ذلك، هناك بعض النقاط التي يمكن تحسينها. أولاً، كان من الأفضل تضمين دراسة مقارنة بين تقنية NSM وتقنيات تقوية أخرى مثل EBR لتقديم رؤية أشمل. ثانياً، لم يتم التطرق بشكل كافٍ إلى تأثير الظروف البيئية المختلفة مثل درجات الحرارة العالية والرطوبة على فعالية تقنية NSM. أخيراً، كان من الممكن تحسين الدراسة بإجراء تحليل عددي باستخدام برامج النمذجة مثل ANSYS للتحقق من صحة النتائج التجريبية.
Questions related to the research
  1. ما هي الأهداف الرئيسية لهذا البحث؟

    يهدف البحث إلى دراسة فعالية تقوية الجوائز البيتونية المسلحة على الانحناء باستخدام شرائح ألياف البوليمر الكربونية بتقنية التقوية بالرصح القريب من الوجه (NSM) وتقييم الجودة الإنشائية للعناصر المقواة.

  2. ما هي المتغيرات التي تم أخذها بعين الاعتبار في الدراسة؟

    المتغيرات التي تم أخذها بعين الاعتبار هي طول ألياف الكربون وعدد طبقات ألياف الكربون المستخدمة في تقوية الجوائز.

  3. ما هي النتائج الرئيسية التي توصلت إليها الدراسة؟

    أظهرت النتائج أن ألياف الكربون تزيد من تحمل الجوائز على الانحناء، وأن استخدام طبقتين من الألياف يزيد من التحمل بنسبة تتراوح بين 40% و72%، بينما استخدام طبقة واحدة على جزء من طول الجائز لا يساهم في زيادة التحمل بشكل كبير.

  4. ما هي التوصيات التي قدمها الباحثون بناءً على نتائج الدراسة؟

    أوصى الباحثون بضرورة دراسة سلوك القص للجوائز البيتونية المسلحة والمقواة بشرائح ألياف البوليمر الكربونية باستخدام تقنية NSM، وأهمية دراسة تأثيرات درجات الحرارة المرتفعة والتحميل طويل الأمد أو المتكرر في الأبحاث اللاحقة.


References used
BUELL, T; SAADATMANESH, H. Strengthening Timber Bridge Beams Using Carbon Fiber. Structural Engineering U.S.A. Vol.131, No.1, 2005, 173-187
TENG, J; CHEN , F . Strengthening of Steel-Concrete Composite Girder Using Carbon Fiber Reinforced Polymers Sheets. Structural Engineering U.S.A. Vol.129, No.1, 2003, 30-40
SPACONE,E; TAWIi,S. Nonlinear Analysis of Steel-Concrete Composite. Structural Engineering U.S.A. Vol.130, No.2, 2004, 159-168
TOM, N; HAMID, S. Shear and Flexural Strengthening of R/ C Beams with Carbon Fiber Sheets. Structural Engineering U.S.A. Vol.123, No.7, 1997, 99-105
BARROS, J; FORTES, A. Flexural Strengthening of Concrete Beams with CFRP Laminates Bonded into Slits. Cement and Concrete Composites. Vol.27, No.5, 2005, 471–480
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