There are various factors that affect the decision to choose reinforced concrete over other construction materials such as masonry, steel and timber. Reinforced concrete has several properties and advantages over other construction materials which makes it favorites for building and other construction.
Why Select Reinforced Concrete as Construction Material for a Structure?
Factors that affect the choice of reinforced concrete over other construction material for building construction include:
- Suitability of the material for structural and architectural functions
- Low maintenance
- Availability of materials
- Fire resistance
Economy of Reinforced Concrete
In most cases, the overall cost of the structure is the first and most important factor that considered. Obviously, the cost of the structure made up of the cost of materials used for the construction, labor cost and time allocated for the construction of the structure.
Comparatively, the thickness of concrete floor is smaller than that of steel structure. This is because floors are flat plates or flat slabs or beams and girder or joists are fitted within the same depth.
Consequently, the overall height of the structure is decreased, which is considerably desired, in comparison with steel floors.
The reduction of the structure height would lead to decrease in wind force of the structure since the exposed area of the building to wind is lesser than that of steel structure.
If the height of the building is decreased, then savings can be made in claddings and electrical and mechanical risers.
There are cases in which the time allocated for the construction of the structure would control the entire cost of the structure. Because contractors need to assign specific budget for the construction, and they will not be able to take their investment back until the building is constructed.
Therefore, it is might be more economical to consider fast construction and receive the investment sooner. This may offset the extra cost used for the formwork and extra material used.
Reinforced concrete materials are broadly available and can be used and casted as per requirements. However, steel elements need to be ordered to be fabricated and should be paid partially in advance to arrange the job at steel fabricating yard.
Any strategy that the designer use to standardize the design and forming will decrease the overall cost. For example, the same formworks can be used for all columns of the structure and using smaller concrete strength at upper storeys will reduce the overall cost of reinforced concrete construction.
Suitability of Reinforced Concrete for Structural and Architectural Functions
It is possible to combine both architectural and structural functions in reinforced concrete system. Fresh concrete can be placed in any forms and shapes and desired textures can be provided through available finishing techniques.
Not only does reinforced concrete structure is capable of serving its main purpose which is supporting loads but also it can provide aesthetically appealing appearances.
The size and shape of reinforced concrete member is controlled by designer.
Fig.1: Reinforced concrete support loads and provide aesthetically appealing appearances
Low maintenance of Reinforced Concrete Structures
Generally, reinforced concrete structure does not require considerable maintenance compared to steel and timber structures.
This advantageous side of reinforced concrete would be more obvious in the case when dense and air entrained concrete is used for exposed areas and sufficient drainage is provided.
Fig.2: Substantially old water tower reinforced concrete structure, still serve its purpose without the need of major maintenance
Availability of Materials for Reinforced Concrete
The constituent of concrete such as sand, gravel and cement are widely available and steel bars are delivered to the construction site easily compared with case of steel element deliveries.
That is why it is recommended to use reinforced concrete for building construction in remote areas.
Fig.3: Reinforced Concrete Materials Available Widely
Rigidity of Structures
Commonly, reinforced concrete structure possesses great rigidity. That is why vibration problem does not frequently occur in reinforced concrete structures.
Fire resistance of Reinforced Concrete
Structures should withstand fire for a period that is enough for the evacuation of the building and prevent the loss of lives and then control the fire. By and large, concrete structures can resist fire for a time ranges from 1 to 3 hours without the need of any special measures to improve building fire resistance.
However, this is not the case for other construction materials such as timber and steel and hence they need to be fire protected to be able to withstand fire for specific time.
This is a strong advantage of reinforced concrete that other construction materials are lacking.
Fig.4: Reinforced concrete structure suffered from extreme fire and still stand and has not collapsed