Solution:

(1) Low Heat Cement:

In mass concrete works like construction of dams, heat produced due to hydration of cement will not get dispersed easily.

This may give rise to cracks. Hence in such constructions it is preferable to use low heat cement. This cement contains low percentage (5%) of tricalcium aluminate (C3A) and higher percentage (46%) of dicalcium silicate (C2 S).

(2) Pozzulana Cement:

Pozzulana is a volcanic power found in Italy. It can be processed from shales and certain types of clay also. In this cement pozzulana material is 10 to 30 per cent.

It can resist action of sulphate. It releases less heat during setting. It imparts higher degree of water tightness. Its tensile strength is high but compressive strength is low.

It is used for mass concrete works. It is also used in sewage line works.

(3) Coloured Cement:

The cements of desired colours are produced by intimately mixing pigments with ordinary cement. The chloralum oxide gives green colour.

Cobalt produces blue colour. Iron oxide with different proportion produce brown, red, or yellow colour. Addition of manganese dioxide gives black or brown coloured cement.

These cements are used for giving finishing touches to floors, walls, windowsills, roofs etc.

(4) Quick Setting Cement:

Quick setting cement is produced by reducing the percentage of gypsum and adding a small amount of aluminium sulphate during the manufacture of cement.

Finer grinding also adds to quick setting property. This cement starts setting within 5 minutes after adding water and becomes hard mass within 30 minutes.

This cement is used to lay concrete under static or slowly running water.