Advantages And Disadvantages Of Cement

It produces lower heat of hydration and has greater resistance to attack of chemical agencies than OPC. Concrete made with PPC is thus considered particularly suitable for construction in sea water, hydraulic works and for mass concrete works.

2.2.1.6 Hydrophobic Cement

Hydrophobic cement is manufactured by adding water repellant chemicals to ordinary Portland cement in the process of grinding. Hence the cement stored does not spoiled even during monsoon. This cement is claimed to remain unaffected when transported during rains also. Hydrophobic cement is mainly used for the construction of water structures such dams, water tanks, spillways, water retaining structures etc.

2.2.1.7 Colored Cement

This Cement is produced by adding 5- 10% mineral

This type of cement can be used with advantage in mass concrete work such as dams, foundations, and abutments of bridges, retaining walls , construction in sea water.

2.2.1.10 Air Entraining Cement

It is produced by air entraining agents such as resins, glues, sodium salts of sulfate with ordinary Portland cement.

2.2.1.11 High Alumina Cement

High alumina cement (HAC) is special cement, manufactured by mixing of bauxite (aluminum ore) and lime at a certain temperature. This cement is also known as calcium aluminum cement (CAC). The compressive strength of this cement is very high and more workable than ordinary Portland cement.

2.2.1.12 Expansive Cement

The cement which does not shrink during and after the time of hardening but expands slightly with time is called expansive cement. This type of cement is mainly used for grouting anchor bolts and pre-stressed concrete ducts.

2.2.2

Aggregates those are chemically inert materials which when bonded by cement paste to form concrete constitute the bulk of total volume of concrete & hence they influence the strength of concrete to a great extent. Depending upon their size, the aggregate are classified as the fine aggregate & coarse aggregates. The material passing through 4.75 mm sieve size is termed as fine aggregates. Natural sand or crushed sand is usually mainly as fine aggregates in concrete mixes.

2.2.3.1 Types of aggregate according to its shape

2.2.3.1.1 Rounded