DESIGN OF RECTANGULAR BEAM ROUND A 5M BY 4M FIRST FLOOR ROOM STRUCTURE

DESIGN OF RECTANGULAR BEAM ROUND A 5M BY 4M FIRST FLOOR ROOM STRUCTURE

CHAPTER ONE

1.0 INTRODUCTION

Plain concrete, a stone-like material made by mixing cement, fine aggregate (sand) coarse aggregate (gravel) and water with specific proportions and at times, other additive (admixture) that modify properties into workable mixture. Plain concrete after preparation and placement needs curing to attain strength. In its unhardened (plastic) state, concrete can be placed in forms to produce a large variety of structural element.

Reinforced concrete is a combination of two dissimilar but complementary materials, namely concrete and steel. Concrete has considerable crushing strength, is durable, has good fire resistance but offers little or no strength in tension but fair in shear.

On the other hand, steel has good properties, poor resistance to fine and very good in both in shear and in compression. Steel reinforcing has usually embedded passively in concrete before the concrete sets.

Reinforcing schemes are generally design to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and structural failure.

Therefore, a combination of these materials results in good tensile and compressive strength, durability and good resistance to fire and shear.

Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers or alternate composite material in conjunction with reinforcement bars.

Reinforced concrete may also be permanently stressed (in compression), so as to improve the behavior of the final structure under working loads.

For a strong, ductile and durable construction the reinforcement needs to have the following properties of;

• High relative strength
• High toleration of tensile strain
• Good bond to the concrete
• Thermal compatibility, not causing unacceptable stress in          response to changing temperature.
• Durability in concrete environment, irrespective of corrosion or sustained stress.

1.1 OBJECTIVE OF THE STUDY

1. The main objective of this design is to achieve an acceptable probability that the structure being designed will perform satisfactorily during its intended life.
2. The design structure should sustain all loads and deform within limits for construction and use.
3. The design structure should be durable
4. The design structure should adequately resist to the effects of misuse and fire.
5. The structure must be economical, that is, the factor of safety should not be too large to the extent that the cost of structure becomes prohibitive with no additional major advantage except for robustness.