Concrete

Concrete is a composite material mainly composed of water, aggregate and cement. Often, additives and reinforcements are included in the mixture to achieve the desired physical properties of the finished material. When these materials are mixed together, they form a fluid mass that is easily molded into shape. Over time, cement forms a rigid matrix that binds the rest of the material together into a durable stone-like material with multiple uses.

The aim is to combine these materials in measured quantities to make concrete that is easy: transport, place, compact, finish, and that will be set, and rigid, to deliver a strong and durable product. The amount of each material (ie, cement, water and aggregate) affects the properties of hardened concrete.

Concrete production

A good quality concrete is essentially a homogeneous mixture of cement, coarse and finagregates and water that consolidates into a rigid mass due to the chemical action between cement and water. Each of the four components has a specific function. The coarse aggregate acts as a filler. The fine aggregate fills voids between the paste and the coarse aggregate. Cement with water acts as a binder. The mobility of the mixture increases with the use of cement paste, fines and nowadays, addition. Stages of construction of concrete: mixing or measuring, mixing, transporting, plating, compacting, curing and finishing materials.

Concrete Batching 

It is the process of measuring solid mixture components or by mass and presenting them into a mixture. Traditionally batching is done by volume, but most specifications require large-scale batching rather than volume. The proportions of different materials are determined by the appropriate mixture design.

A concrete mix is ​​designed to produce concrete that can be easily laid at the lowest cost. When plastic is strong, it must be solid and solid to make it strong and solid. The mixture design must consider the environment that will be in the concrete; That is, at the peak of sea water, trucks, cars, forklifts, foot traffic or hot and cold. Proportional concrete is a mixture of cement, water, coarse and fine aggregate and penetration. The ratio of each material in the mixture affects the properties of the final hardened concrete. These ratios are best measured by weight. Measurement by measurement is not as accurate, but is suitable for small projects.

As the cement content increases as the cement content increases, so does strength and durability. Therefore to increase strength, increase the cement content of a mixture. Adding more water to the mixture gives the water content a weaker hardened concrete. Always use as little water as possible, just enough to make the mixture workable. As the water to cement ratio increases, the strength and durability of hardened concrete decreases. To increase the strength and durability of concrete, reduce the water-cement ratio. A much finer aggregate gives a viscous mixture. Too much aggregate gives a hard or bony mixture. Concrete should be mixed so that cement, water, aggregates and admixture mixes in a uniform mixture. Concrete is usually mixed by machine. Machine mixing can be performed on site or may be a pre-mixed concrete company. Pre-mixed concrete is proportioned (proportioned) to the job requirements in the plant. Material mixing trucks are normally added to the trucks batching the plants and mixed for the required time and speed at the plant. The truck's drum rotates to excite the concrete as it approaches the site. Site mixing When site mixing begins by loading a measured amount of coarse aggregate into the mixer drum. Add both to the measured amount of sand before cement.

The Mixture

The mixing operation consists of rotation or stirring, the purpose of which is to coat all aggregate particles on the surface with cement paste and to blind all the components of the concrete to a uniform mass; This uniformity should not be disturbed by the process of discharging from the mixer. Mixing can be done manually or by mechanical methods such as batch mixer, tilting drum mixer, non tilting drum mixer, pan type mixer, dual drum mixer or continuous mixer.

There are no general rules on the order of feeding ingredients in a mixer as it depends on the properties of the mixer and the mixture. Usually a small amount of water is fed first, followed by all solids. If possible, the greater part of water should also be fed at the same time, the rest should be added after solids. However, when using a very dry mix in a drum mixer it is necessary to feed the coarse aggregates just after the small coarse water feed to ensure that the aggregate surface is sufficiently wet.