The concrete is manufactured using cement, sand, gravel and water as the main components materials. The active material in concrete is cement which binds other materials physically and chemically with water and solidifies. Sometimes admixtures are used in concrete to enhance its properties.
Components or Materials of Concrete
There are various types of cements used for manufacture of concrete, but most commonly Portland cement is used. Each type of cement provides different properties to concrete. Limestone and clay are used for manufacture of cement.
The type and quality of aggregates to produce concrete varies based on the purpose of construction. The shape, size, grain, density and grading of aggregates etc. all affects the workability, durability and strength of concrete. The aggregates are classified as fine aggregates (sands) and coarse aggregates (gravel).
It is best to say that water suitable for drinking is used for concrete production and construction. The water used for concrete should be clean and free from vegetation, deleterious matter and acids.
Admixtures are used in concrete to modify properties of normal concrete to suit the requirements as per construction design.
Storage Methods of Concrete Materials
The method of storing materials of concrete depends on the scope of the work. The following precautions need to be considered during their storage:
Storage of Cement
Wherever possible, the cement should be stored in weatherproof shed and kept dry. The shed should preferably be without any openings such as windows. The doors of such storages shed should be on leeward side to prevent rain penetration and draughts.
The floor for cement storage should be made of strong boards and joists raised clear to the grounds, or of blanks load on a dry concrete slab above ground level. All cement should be stored for the shortest possible time.
Storage of Aggregate
These should always be kept in a clean condition and should not become contaminated with undesirable substances. Aggregate on medium- to large scale building sites are usually stored in bins. The floor of the bins is made of weak concrete and drained or laid to falls. The barriers or walls are built of stout planks, sleepers or concrete blocks.
Aggregates are stored in adjoining bins but with dividing walls that high enough to cope with the highest stockpile without over spilling.
Layout of storage
Aggregate bins, mixers, cement sheds and water supply should be arranged to permit good access to materials, and the easy transport of concrete from the mixer to the delivery point.