concrete plant

Sarchia Khursheed Soran University – Civil Engineering Dpt.

11 November 2015

Scientific Trip for a Concrete Plant

Ready Mixed Concrete

Ready mixed refers to concrete that is batched for delivery from a central plant

instead of being mixed on the job site. Each batch of ready-mixed concrete is

tailor-made according to the specifics of the contractor and is delivered to the

contractor in a plastic condition, usually in the cylindrical trucks often known as

"cement mixers."

Manufacturing of Concrete

Step1: Implementing the product received

Receiving facilities for aggregates make it possible for trucks to unload their goods

directly into a hopper (large funnel-like device) which feeds the product through a

conveyor belt.

The cement is delivered by tanker trucks that unload their cargo in silos via

pneumatic pipes under compressed air pressure.

Step 2: Storage of aggregates

Aggregates are stored in silos, in hoppers, or on the ground. The storage of

aggregates allows the batch plant to have several days worth of storage.

Step 3: Adjuvants (additives)

Admixtures or additives are added at the time of manufacturing to obtain fluidity,

and to accelerate or delay setting time.


11 November 2015

Step 4: Storage of cement

Cement is stored in silos equipped with a dust collection venting system. There

are as many silos as there are types of cement.

Step 5: Mixing

Mixing: The mixer blends the cement, sand, gravel and adjuvants supplied by the

PLC (Programmable Logic Controller). A mixer must contain up to 3 m3.

The time and the quality of the mixing are important factors so as to produce a

good product. They are controlled by a programme.

Step 6: Control Station

The batch plants are all equipped with PLC’s to automate control production.

They allow for better selection with rigorous standards, of a formulation adapted

to the concrete ordered by clients, and according to the dosage in water

corresponding to the hygrometry of

aggregates.

Cement, sand, gravel, water and

adjuvants are dosaged (measured) and

weighed with extreme precision.

Step 7: Delivery

Fresh concrete is brought to the site via mixer-trucks with a capacity of 6 to 8 m3,

in which it is generally mixed before delivery to clients. Delivery logistics

constitute an essential part of the process because of cement’s setting time which

is limited.


11 November 2015

Advantages of using Ready Mixed Concrete

Reduction in cement consumption by 10 – 12 % due to better handling and proper mixing. Further reduction is possible if mineral admixtures or cementitious materials are used.

Since ready mixed concrete (RMC) uses bulk cement instead of bagged cement, dust pollution will be reduced and cement will be saved.

Conservation of energy and resources because of saving of cement.

Environment pollution is reduced due to less production of cement.

With better durability of structure, their overall service life increase and there is saving in life-cycle cost.

Quality assurance due to mechanical handling and uniformity of processes.

Eliminating or minimizing human error and reduction in dependency on labour.

General benefits like speedy work, stability of structures, etc.

Lean concrete

Lean concrete is made with low cementitious

material content. This means that it does not have

many of the heavy, high-density rock and sand

elements that normal concrete has. Instead, it can

use a mixture of standard concrete materials,

reclaimed and crushed concrete, discarded sand

and recycled ash. This makes lean concrete very

cheap in nature and simple to make and use.