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Register a new userFormation of cracks in the reinforced concrete walls related to Foundation – Problem and Solutions
تشكل الشقوق في الجدران البيتونية المسلحة المرتبطة بالأساس – المشكلة و الحلول
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زكائي طريفي( باحث )
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تعتبر الشقوق من العيوب الهامة في العناصر البيتونية، لوحظ بعد صب الجدران البيتونية المسلحة المرتبطة بالأساس أنه بعد فترة زمنية قصيرة من تصلب البيتون، و دون أي تحميل للجدران تتشكل شقوق طولية نافذة و عادة تكون بمسافات منتظمة على طول الجدار مما استرعى انتباهنا لهذه الظاهرة، و قد حصلت في عدة مشاريع هندسية. قمنا من خلال هذا البحث بوصف الحالة، و شرحها، و تحليلها، و دراسة أسباب تشكلها. و ذلك من خلال دراسة ميدانية لثلاثة مشاريع هندسية منفذة في اللاذقية و هي عبارة عن حوض ترسيب، و مبنى فندق سياحي و مول تجاري، حيث تراوح عرض الشقوق مابين 1.25 mm و حتى 3 mm، و اختلف ارتفاعها في كل حالة مدروسة. تم في ختام البحث وضع الحلول العملية لتجنب هذه الظاهرة و منها اعتماد فواصل طولية للجدران البيتونية المسلحة بتباعد حوالي ثلاثين مرة سماكة الجدار و ذلك لتجنب الشقوق الناجمة عن التقلص و الإجهادات الحرارية، حيث يكون عمق الفاصل حوالي 20 mm و عرضه مابين 15 mm حتى 20 mm و ينفذ من جهتي الجدار الداخلية و الخارجية. بعد تصلب البيتون و فك القالب الخشبي تملأ هذه الفواصل بمواد مالئة مرنة.
Cracks are considered important defects in concrete elements, it was noticed after constructing the reinforced concrete walls related to the Foundation, that after a short time after the hardening of concrete and without any overloading on the wall, there have been vertical cracks of regular distances along each wall we noticed this phenomenon it had happened in many construction projects. We have described the situation, we have also explained, analyzed it by examining its reasons. By a thorough study of three projects carried out in lattakia including scale decanter, building of a tourist hotel and a trade centre, which crack width ranging from 1.25 mm to 3 mm, the height differed in each case studied. Ultimately we have found the practical solutions to avoid this phenomenon including adoption of longitudinal joints for reinforced concrete walls, spacing is about thirty times the wall thickness in order to avoid cracks caused by shrinkage and thermal stress where the depth of joint about 20 mm and the width ranging between 15 mm to 20 mm implemented on both sides of the wall internal and external. After hardening of concrete and lifting the wooden template fill the joints with filler flexible materials.
References used
الكود العربي السوري لتصميم و تنفيذ المنشآت بالخرسانة المسلحة. الطبعة الرابعة، دمشق، 2012, 404.
.Lohmeyer , Ebeling : Weisse Wannen - einfach und sicher .- VBT - Verlag Bau und Technik, 2009, 461 Seiten
.Röhling: Zwangsspannungen infolge Hydratationswärme .- VBT - Verlag Bau und Technik, 2009, 444 Seiten
.Dieter Ansorge : Bauwerksabdichtung gegen von aussen und innen angreifende Feuchte .- Fraunhofer IRB Verlag, 2011, 300 Seiten
.Frank Frössel : Risse in Gebäuden .- Baulino Verlag, 2009, 440 Seiten
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