- Cement is a material which has cohesive & adhesive properties in the presence of moisture.
- Cement is a product consumed by the pulverizing clinker formed by calcination of the raw-materials primarily consisting of Lime (CaO), Silicate (SiO2), Alumina (Al2O3) & the Iron oxide (Fe2O3).
- Cement was invented by the British scientist Joseph Aspdin in 1824, he named it Portland cement because of the hardened concrete made out of the cement aggregates & water in definite proportion resembled by the natural stones occurring at Portland in England.
What is concrete?
- When cement is mixed with water it forms a paste which hardens & binds aggregates together to form a hard & durable mass which is known as concrete.
Cement used in construction by two types:
- Hydraulic Cement: This kind of cement set & hardens in the presence of moisture or water & results in the water-resistant product which is stable for example Portland cement.
- Non-hydraulic: Cement is derived from calcination of gypsum or limestone because their products of hydration are not resistant are not resistant to moisture; however, the addition of pozzolanic materials can render gypsum & lime concrete hydraulic for example Plaster of Paris.
Technical terms:
Pulverize: is defined as the make into the powder by breaking up or cause to become dust.
Clinker: A hard brick used as a paving stone.
Calculations: The process of heating substances to a high temperature but below the melting or fusing point, causing loss of moisture, reduction an oxidation & dissociation into simpler substances.
Hydration: The chemical reaction between cement & water which tends to bind the aggregates with cement.
Cohesive: The intermolecular attraction that holds molecules and masses together.
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