Concrete Mixture

Cement

Initially used by the ancient Egyptians & was developed not later the late 19th century, open a new era  for modern architecture particularly of the Brutalist period. It is 4 parts calcined limestone plus 1 part clay which are mixed, burned and pulverized, sold in 40 or 50 kilos per bags in the market


There are Types of Cement


Portland Cement – named after it resembles a unique  limestone found in the Isle of Portland, England (hydraulic cement made by burning a mixture of clay and limestone in rotary kiln resulting into clinker, further pulverized into very fine powder)
  • Type I  : Normal - Portland cement for general construction
  • Type II : Moderate - sulfate resistant, where heat build-up can damage the structure
  • Type III : High Early Strength ( HES ) - cures faster ( 3 - 7 days) and gains earlier strength
  • Type IV : Low Heat - generates less heat hydration where heat build-up can significantly damage the structure and used for massive concrete structures
  • Type V : Sulfate Resistant - used where resistance to severe sulfate action is required that damage the structure when it leach out from the soil.
Pozzolan Cement – named after a natural cement from Puzzuolli, an ancient Roman town near Mt. Vesuvius, It is commonly use for masonry works such CHB mortar, wall plastering, slab on grade and other non-load bearing structures

Sand – or fine aggregates, natural sand or crushed stone well graded with size from 0.003-¼ inch (0.076 - 6.4mm )

Gravel – or course aggregates, crushed stone or blast furnace slags with size from ¼ inch - 1 ½ inches (6.4mm - 37.5mm) 

Water – clean, potable & free from harmful substances, Water cement ratio controls the strength, durability and water tightness of hardened concrete.

Admixture – or additive as required by situations, ingredients added to concrete or mortar modify its  properties immediately before or after mixing.

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