What is Cement?
Cement is a fine powder, which when mixed with water undergoes chemical change and thereafter allowed to set and harden is capable of uniting fragments or masses of solid matter together to produce a mechanically strong material.
Cement can be used as binding material with water, for bonding solid particles of different sizes like bricks, stones or aggregate to form a monolith. Cements used in construction of buildings and civil engineering works contain compounds of lime, silica and alumina as their principal constituents and can be called as complex compounds.
The installed capacity of the Indian cement market is estimated at about 230 million tonnes as of 2008–09.
The production of cement in 2008–09 was recorded at 187.61 million tonnes. Further, the industry is expected to augment capacity by about100 million tonnes by 2013 to meet future demand.
The industry recorded a CAGR of about 7.3 per cent in installed capacity between December 2004 and December 2009.
The Indian cement industry recorded a turnover of US$ 18.5 billion in 2008.
The Cement Manufacturer's Association of India (CMA) estimates the industry manpower at about 140,000 as on 2009
Cement players in India produce different types of cement based on varied compositions such as Ordinary Portland, Portland Pozzolana, Portland Blast Furnace Slag cement, white cement and specialised cement.
Type Of Cement
Cargo Power & Infrastructure products include:
Ordinary Portland Cement
Ordinary portland cement is the most commonly used cement for a wide range of applications. These applications cover dry-lean mixes, general-purpose ready-mixes, and even high strength pre-cast and pre-stressed concrete.
Portland blast furnace slag cement
Portland blast-furnace slag cement contains up to 70 per cent of finely ground, granulated blast-furnace slag, a nonmetallic product consisting essentially of silicates and alumino-silicates of calcium. Slag brings with it, the advantage of the energy invested in the slag making. Grinding slag for cement replacement takes only 25 per cent of the energy needed to manufacture portland cement.
Using slag cement to replace a portion of portland cement in a concrete mixture is a useful method to make concrete better and more consistent. Portland blast-furnace slag cement has a lighter colour, better concrete workability, easier finishability, higher compressive and flexural strength, lower permeability, improved resistance to aggressive chemicals and more consistent plastic and hardened consistency.
Portland Pozzolana cement
Portland pozzolana cement is ordinary portland cement blended with pozzolanic materials (power-station fly ash, burnt clays, ash from burnt plant material or silicious earths), either together or separately.
Portland clinker is ground with gypsum and pozzolanic materials which, though they do not have cementing properties in themselves, combine chemically with portland cement in the presence of water to form extra strong cementing material which resists wet cracking, thermal cracking and has a high degree of cohesion and workability in concrete and mortar.