Construction methods and benefits of ferro-cement

Ferro-cement alias thin-shell concrete or ferro-concrete stands for a composite material made of a mortar reinforced with light steel fabric/mesh that is applied to develop thin sections.

The construction method involves building up the shape of the necessary structure by a mesh of fine reinforcement like chicken wire or extended metal. Various layers are utilized to attain the desired density of steel and the entire is hardened with a few standard reinforcing bars. A rigid mortar is then employed to both sides of the layer of reinforcement called as the ‘armature’ and finished to the desired thickness.

Wire mesh is normally comprised of 0.8 to 1.00m diameter steel wires at 5mm to 50mm spacing and the cement mortar contains cement sand ratio of 1:2 or 1:3. 6mm diameter bars are also employed at bigger extent, desirably in the corners. Sand is substituted with baby jelly. The water cement ratio remains among 0.4 to 0.45.

Lots of labors are required to implement the method since the mortar is usually provided by hand. But it can also be sprayed.

So, it’s application is found in developing countries where labor costs are low. It is also suitable for roof shells and in decorative purposes. It can be also applied water tanks, storage structures etc.

Ferro-cement reinforcement is fabricated into its final required shape and plastered directly. No form work should be carried on. At least two layers of reinforcing steel meshes are necessary. American Concrete Institute defines “Ferro cement as a thin walled reinforced concrete construction where normally a hydraulic cement is reinforced with layers of mesh with continuous and comparatively small diameter.

Also Read: How to find out the quantity of cement and sand in plastering work

The metallic or any other suitable material can be used as mesh. Ferro-cement is considered as a good substitute for timber. Ferro-cement can provide the finish of teak wood, rose wood etc as well as for producing tables, chairs and benches.

Characteristics of Ferro-cement

1. Its stability per unit mass is superior.
2. It can easily withstand shock load.
3. It can provide pretty finish similar to teak and rose wood.
4. No form work is required to develop ferro-cement materials.
5. It is impermeable.

Applications of Ferro-cement - It is applied for the following purposes :

1. Partition walls
2. Window frames, chejjas and drops
3. Shelf of cupboards
4. Door and window shutters
5. Domestic water tanks
6. Precast roof elements
7. Reapers and raffers necessary for supporting roof tiles.
8. Pipes
9. Silos
10. Furnitures
11. Manhole covers
12. Boats

Ingredient required for Ferro-cement

1. Cement
2. Fine Aggregate
3. Water
4. Admixture
5. Mortar Mix
6. Reinforcing mesh
7. Skeletal Steel
8. Coating

Benefits

• Basic raw materials for ferro-cement can be easily obtained in most countries.
• Fabricated into any required shape.
• Sound labor skill is not necessary.
• Simple construction process, low weight and good longevity.
• Fewer construction materials cost.
• Strong resistance capacity against earthquake.

The construction method of ferro-cement involves the following steps :-

• Fabricating the skeletal framing system.
• Providing rods and meshes.
• Plastering.
• Curing