Concrete is a widely used construction material which is a mixture of cement, aggregates, water and admixture. The concrete is the very first choice for the civil engineering industry as it is more conventional material readily available and cheap while it has some good properties like excellent durability, mouldability, can be produced with the industrial byproducts and having less energy input. Even though, in the trending world of the lightweight materials, concrete is the only a construction material being used for the construction of foundations, tie beams, ground slabs and other underground and sea terrain buildings.
The concrete is a chemical reaction taking place in between all its component to provide the intended strength to the structure. The stiffening, solidification and hardening are the three main physical aspects of the setting and hardening process of concrete from its fresh state.
Properties of the Concrete
- Strength
- Workability
- Durability
Types of Concrete used in the Industry
The requirement of concrete properties is varying depending on the types of structural elements, geometrical features of the structure, time of concrete placement and number of skill labourers. So based on the situation and type of structure, the concrete can be categorised as several types as follows. Each of these types are having different properties within themselves with respect to strength, workability, porosity, setting time etc…
- Normal concrete
- High strength concrete
- High performance concrete
- Self compacting concrete
- Pervious concrete
- Light weight concrete
- Aqua concrete
Grades of concrete
The process of selecting the proper grade of concrete is important to arrive at an economical and durable material. In this manner the grade of the concrete is taking a big role here. Generally the mix designs are prepared based on the requirement of strength, workability and durability for the project specifications. The grade is generally denoted as M30, which means the compressive strength of the concrete M30 is 30 MPa. The grade of the concrete is very much likely depending on the mix proportion of its component other than the workmanship at the site. Each and every component of the concrete playing a major role in the function.
This mix proportions for each grades of normal concrete is as follows with the denotation of cement : fine aggregates : coarse aggregates,
| Grade of Concrete | Mix Proportion |
| 10 | 1 : 3 : 6 |
| 15 | 1 : 2 : 4 |
| 20 | 1: 1.5 : 3 |
| 25 | 1 : 1 : 2 |
The concrete mixing can be done manually for small scale projects and the ready mix concrete are used in the big scale projects where tons of concrete are in need.
Test carried out on Concretes
- Slump test
- Cube test
- Temperature check
