Applications Of Ferrocement

1.Widely used in domestic overhead tank.This tank is light, flexible, easy to transport and cheap.

2.Different types of inlet and outlet connections can be easily done with the help of adhesive using ferrocement.

3.It can be used as "gasholder" in "gobbar gas plant".
4.With slight modification ferrocement tanks can be used as grain silos in villages to keep grains

5.Can be used as septic tank.

6.Ferrocement is ideal for boat building.This kind of boat weighs 10% less if it is made of wood.

Ferrocement

Ferrocement is a relatively new material consisting of mortar made with portland cement, water and aggregate with reinforcing mesh.
P.L. Nervi an Italian engineering and architecture developed this material in 1940.

Advantages of Hydration

1.Because of hydration cement get adhesive property and bind fine and coars aggregate.

2.Helps in joining bricks.

3.Binds rids with concrete in R.C.C(Reinforced Concrete Cement).

4.Make the cement paste rigid.

Concrete

Concrete is a rock like material, which is made by mixing cement, coarse aggregate and fine aggregate with water.

Endogeneous or endogen timber

This kind of trees increase both longitudinally and diametrically.Its diameter increase by the addition of new fibre with the old. Endogens are mostly plants like paddy, sugarcane, jute etc.

Exogeneous or exogen timber

This kind of trees increase diametrically by annual formation of layer new wood between old wood and bark of the wood which consists all the living portion of the tree.

Types of Timber

Timber is of mainly two types.
1.Exogeneous or exogen
2.Endogeneous or endogen

Relation between water cement ratio to the strength of concrete

Water has three functions in concrete

1.Wets aggregate surface
2.Imparts workability
3.Binds aggregate with cement chemically by hydration

For a given degree of compaction with the increase
of percentage of water, percentage of hydration increases.
So sufficient amount of water is necessary for hydration as well
as for increase in strength.Water also imparts workability to
concrete.but excess water cause concrete to be porous.
Hence for a certain limit strength increase with the increase of
water cement ratio.But after that strength decreases with the
increase of water cement ratio.

Why fineness of cement is necessary for rapid development of strength

The surface area of cement particles increases with the increase of fineness modulus. Hydration takes place on the surface area of cement particles.For rapid hydration surface area of cement particles should be high.Strength develops on the concrete as hydration takes place. This is why for rapid development of strength high fineness of cement is necessary.

Placing concrete underwater

Sometimes concrete needs to be placed underwater.In this case bottom dump bucket or tremie pipe is used. In this case concrete is carried through the water in water tight box by bottom dump bucket and reaching the final position there is a mechanism to open the bottom of the bucket and dispose the concrete. This will not give satisfactory result as some concrete get washed away.

Sometimes dry cement and dry coars aggregate and fine aggregate are mixed in a cement bag and disposed under water. This also do not give satisfactory result as cement bag make voids in concrete.

Among the two tremie pipe method is preferable.