Concrete and Process of Concreting

Concrete Defined as a building material obtained by mixing cement, aggregates and water in suitable proportions. Which when allowed to cure becomes hard like a stone. Three ingredients of concrete

1. Cement 2. Aggregates 3. Water

OPC conforming to Indian Standard specification is used Aggregates are inert or chemically inactive materials which form the bulk of cement concrete.

Two types of aggregates: Coarse and Fine.

Coarse form the main matrix and Fine forms the filler matrix Aggregates should be clean, free from organic matter and other impurities It must be sound and resistant to weathering action. Aggregates should be well graded for obtaining good quality concrete The quality of water used is very much important. Impurities present in it may interfere with the setting of cement, affect the strength, staining of its surface, corrosion of reinforcement etc. The quality of concrete depends on amount of water used. Presence of various salts in sea water adversely affect the qualities of concrete and it is not preferred.

Cement Mortar: Preparation and its uses

• Paste prepared by adding water, cement and fine aggregates.
• Used in stone or brick masonry and plastering walls.
• The components of mortar, binding material – Matrix, Fine aggregate- Adulterant.
• Matrix binds adulterant
• Durability, quality, and strength depends on matrix quantity and quality.
• Mortar binds the bricks or stones firmly.   

Preparation of Mortar  

• Water is added to the intimate mixture of cement and sand.
• Water should be free from clay and other impurities
• Water fir for drinking is used

Different mortar prepared in the following ways,