Back in the day constructions by concrete were mainly concerned in the facts of unique load bearing capacity and the cost effectiveness. But with the evolution of the society over the last decade has brought the requirement of having unique and astonishing aesthetic finishes in concrete designs as well. With the development of Self Compacted Concrete, the possibility of incredible concrete designs and high-quality finishes has come to light.
Using common construction material such as Grade 30OPC Cement, Fine Sand, Coarse Aggregate (Metal) and form-works made out of good timber, steel or Aluminum will guide you to having your own desired concrete finishes.
What is fair-faced Concrete?
As in the meaning of the collective term ‘fair-faced’, these concrete designs tend to produce smooth and aesthetic surfaces within all kind of shapes. Rather than pouring and casting on the site, these concrete designs can be pre-casted according to the architectural and Load bearing demand of the structure as well. Fair-Faced concrete mainly depends on 3 factors. Form work, Concrete Mixture and Curing and Placing Methods.
Aesthetic appearance of the fair faced concrete originally depends on the quality of the form-work. The form work needs to be impervious or the finish of the surface will not produce the expected quality.
Form work material such as untreated timber would result in having considerable retardation leading into discoloration and dusting as well. Therefore, the form-work materials must be selected with sincere concern.
Surface texture effects are also generated from the materials used in form-work. Vastly used form-work materials such as roughly sawn timber, steel or aluminum provide unique textures in the concrete surfaces.
Concrete Mixture of fair-faced Concrete
Concrete is to be taken as the vastly used construction material in industry due to its’ load bearing capacity and the cost effectiveness ratio. Usually a concrete surface tends to rough with constant un-conformities. So, creating a fair faced surface while keeping the initial properties of the concrete is taken to be challenging.
To overcome this challenge, certain practices are widely used in manufacturing fair faced concrete Shapes.
- Using a minimum amount of fines content
- Making the density of the mixture to be over than 300 kgm-3
- The Water content must be ideal, Otherwise the concrete would show fluctuations or bleeding effects due to presence of superfluous water
- Regarding the colour, the effect of the cement needs to be considered in the finishing colour of the surface.
Curing and Placing
In order to ensure the quality and the consistency of the concrete the curing and placing methods have to analyzed thoroughly as well.
- The concrete should be laid in even strips with thickness varying from 300mm -500mm.
- Each layer needs to be vibrated thoroughly into the layer below while ensuring the expulsion of air bubbles.
- Concrete should have enough plasticity to have soft consistence installations
To manure the concrete is such unique manners, it needs to be subjected to several enhancers to improve certain qualities. In Concrete these enhancers are commonly referred as admixtures. Generally used admixtures in the production of fair-faced concrete panels, or the structures can be identified as follows,
|Mold Releasing Agent|
|To make striking and clearing easier|
|To improve the quality of the surface by reducing|
presence of pores and blow holes
|To prevent premature curing|
|Colouring||To create even and demanding colours in the concrete.|
|To increase the strength|
To increase the impermeability
Advantages of fair-faced Concrete
1. Ability to cutoff the cost for Plastering
In local construction Industry cost for plastering 1m2 concrete wall space lies around Rs. 120.00 – Rs.130.00. Simply by switching your concrete designs into fair faces, the cost for plastering can be avoided in a highly benefit-able manner. Instead of plastering the concrete wall or the structure,
2. Availability of panels in preferred Sizes
Rather than forming the concrete and grinding the concrete in site (In situ), pre casted concrete panels can be bought from plants which carries smooth surfaces along with high load bearing capacities as well.
These panels produce the capability of having 2-3 story buildings without the involvement of high rising columns, while giving a neat surface which is ideal for skim coat and painting. The cost of construction also reduces in a significant manner due to abundance of structural columns, Plastering.,etc.
3. Reduced wastage of materials
When concrete or the cement slurries prepared in the site, considerable amount usually get wasted while mixing, transporting, and placing.
Making the in-situ concrete into fair faced surfaces would help in reducing the wastage since the abundance of plaster is guaranteed by them. In the other hand using pre casted panels will reduce the wastage even further due to abundance of plaster and minimum usage of concrete as well.
4. Possibility of Various Shapes
With the right material and formwork, your imaginations become the limit for concrete designs. With the availability of aesthetic and smooth finishes in concrete (Fair Faced) the possibility of having any kind of desired shape has come to light in modern architecture.
Quality Assurance Engineer (Civil)