What is concrete?

Concrete is the most widely used man-made construction material in the world and is second only to water as the most utilized substance on the planet.

It is obtained by mixing cementing materials, water, aggregate, and sometimes admixtures in the required proportion.

The mixture when placed in forms & is allowed comes to harden into a rock-like mass known as concrete. The hardening is caused by chemical reactions between water and cement & it continues for a long time & consequently, and grows stronger with age.

What is Concrete (ingredient) — Concrete

Strength, durability & other characteristics of concrete depend on the properties of its ingredients, the proportion of the mix, the method of composition, and after-control during placing, compaction & curing.

The popularity of concrete is due to the fact that from common ingredients. It is possible to tailor the properties of concrete to meet the demands of any particular situation.

Concrete Ingredients

We need some ingredients for producing strong, durable & uniform concrete. That is high in performance and lies in being careful use of its basic & processed components. These are the following ingredients:-

Cement

It is the most widely used cementing ingredient in present-day concrete that consists of compounds Ca, Si, Al, Fe & O2. It is an extremely ground material having adhesive properties that provide a binding medium for the discrete ingredients, identification of the major complex compounds is largely based on bojuis work & these are called bojuis compounds.

Bojuis compounds: –

S.N.	NAME	CHEMICAL FORMULA	PERCENTAGE
1.	Tri calcium silicate(C₃S)	3CaO.SiO₂	30 – 50
2.	Dicalcium silicate (C₂S)	2CaO.SiO₂	20 – 45
3.	Tri calcium aluminate (C₃A)	3CaO.Al₂O₃	8 – 12
4.	Tetra calcium aluminate ferrite (C₄A)	4CaO.Al₂O₃.Fe₂O₃	6 – 10

S.N.	CONSTITUTES	PERCENTAGE	AVERAGE
1	Lime (CaO)	62 – 67 %	63
2	Silica (SiO₂)	17 – 25 %	20
3	Aluminum (Al₂O₃)	3 – 8 %	6
4	Iron oxide (Fe₂O₃)	0.5 – 6 %	3
5	Magnesium oxide (MgO)	0.1 – 4 %	2
6	Sulfate trioxide (So₃)	1 – 3 %	1.5
7	Soda & potash (Na₂O + K₂O)	0.5 – 1.3 %	1

Aggregate

These are mainly naturally granular materials such as sand, gravel, and crushed stone. However, technology is the use of recycled material & synthetic products.

Type of aggregate

Coarse aggregate
Fine aggregate

Water

water content, minerals & chemicals dissolved in it are achieving quality concrete.

Chemical admixtures

These are the ingredients in concretes other than Portland cement, water, and aggregate that are added to the mixture immediately before or during mixing to reduce the water required to accelerate or improve specific durability characteristics.

Supplementary cementing material

It is also called mineral additive, it contributes to the properties of hardening concrete through hydraulic or pozzolanic activity. Typical engineering of natural pozzolanic is fly ash and silica fumes.

Also, read

What is Concrete?