SLAB STAGES

IMPORTANT COMPONENTS

Key in column

Water bar

Binding materials

Expansion joint

KEY IN COLUMN

since the height of column is very large, hence it is not possible to cast the column at one time, to cast the column later the key is made at the junction so that the proper bond between the old concrete and new concrete is formed.

KEY IN COLUMN

EXPANSION JOINT

Since concrete is subjected to volume change. Provision must be made to cater for the volume change by way of joint to relieve the stresses produced.

Expansion joint is function of length Buildings longer than 45 m are generally provided with one or

more expansion joints. Material used as expansion joint material is armour board

whose thickness is 25 mm.

EXPANSION JOINT

Expansion joint material, size is 25 mm

Expansion joint in building

WATER BAR

Water bar is provided in the retaining wall o that the moisture can’t move from the soil to the joint. Water bar is basically provided at the constructions joints of retaining wall of two different towers

WATER BAR

BINDING MATERIALS

Since the thermal expansion of concrete is different from that of masonry. The interface between the concrete and the masonry is liable to crack. To avoid this crack the chicken wire mesh is used to avoid the crack and also provides the better grip for Masonry with concrete.

Similarly when the drainage pipes are laid along with the outer wall then again the connection between the pipe and the wall has different coefficient of temperature change hence they are joint to the concrete by lead keys.

In the toilets and kitchen sunken portion the joints in any case are packed by water proof and non shrinkable material.