Effect of boundary restraints on the ultimate capacity of square concrete slabs reinforced with minimun amount of reincement

مقدم أطروحة جامعية

Ali, Walid Hamid Muhammad

الجامعة

الجامعة التكنولوجية

الكلية

-

القسم الأكاديمي

قسم هندسة البناء و الإنشاءات

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2008

الملخص الإنجليزي

In this research a rigid-plastic solution is presented for predicting the ultimate strength as well as determining the post yield behaviour of uniformly loaded reinforced concrete square slabs which have various restrained edges. Based on the simple yield line theory, the correct mode of failure and the associated collapse uniform load arc determined for all six cases of the slab.

In each case, the true collapse mode is specified which has been found to depend largely on the restraining conditions of the slab edges. Adopting the patterns of failure predicted by the yield line theory, upper bound rigid-plastic solutions are presented for all cases investigated which take into account the significant effects of membrane forces inducing in the plane of the slab with continuing deflection.

Therefore these solutions describe the load-deflection behaviour of such slabs under the combined effect of bending and membrane action. The load-deflection behaviour of a specified reinforced concrete slab has been found to be largely affected by many parameters including the steel ratio/? T concrete strength, yield strength of steel f and most importantly the supporting condition of the slab edges.

Similar to the behaviour of completely restrained slabs, the results show that partially restrained slabs can also sustain loads higher than those predicted by Johansen's yield line theory (though with a lesser margin) and the enhancement in load is greatest for thinner slabs having lighter reinforcement and smaller rectangularity. An equation describing the effect of the slab boundary restraints on the initial collapse load (including membrane action) of rigid - plastic R.C square Slabs is derived and reported for the first time.

The equation verifies that a The benefit of including the effect of membrane action in the analysis of R.

C square slabs is demonstrated.

Aparticular example of a R C slab (having all, edges fixed and reinforced with the minimum amount of reinforcement specified by ACI 318 - 05 code) is considered which remarkable increase intheactual uniform live load carrying capacity by four times that estimated by the simple yield line theory and twenty that predicted using method three of the 1963 ACI Code.

التخصصات الرئيسية

الهندسة المدنية

الموضوعات

• الخواص الميكانيكية

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-305474