Concrete

What is concrete?

Concrete is a construction material made from cement, sand, and gravel or stones, and it is one of the most used materials in architecture and engineering projects worldwide. One of its main characteristics is its high malleability, great consistency, low cost, and fast drying time.

How is concrete made?

The key to making concrete is achieving a homogeneous mass from the mixture of materials that make it up: binders (cement), dry aggregates (gravel or sand), and water. The proportions will vary depending on how the material will be used. The more liquid added, the easier it will be to handle, but it will also be less resistant.

First of all, you have to mix the dry materials – the cement, sand, and gravel – until everything is homogenized. The indicator that this has happened is that the mixture takes on the grayish color of cement. Then, water must be added little by little to mix it progressively and evaluate the consistency that the concrete acquires.

What types of concrete are there?

There are different types depending on their use, properties, aesthetics, construction method, and durability:

• Mass concrete: it is used in large volumes with dimensions of more than three meters. When used in this way, special attention must be paid to the effects of cracking, which occurs due to thermal shock between the internal part of the concrete (which may be hot due to the cement hydration process) and the external part (which usually cools down more quickly). 

• Structural concrete: it is usually used in any type of civil works or building, and its main characteristic is that it is used to extend the durability of these projects.

• Lightweight concrete: this variety is also called cellular concrete, and it aims to reduce density and improve thermal and acoustic insulation. In addition, it is often used to regularize uneven floors, lighten structures, or rehabilitate roofs in poor conditions.

• Reinforced concrete: this consists of adding a metallic iron structure to concrete in order to give the structure greater resistance. It is one of the most commonly used types in building tunnels, bridges, buildings, roads, columns, etc.

• Prestressed concrete: this kind aims to improve the natural weakness of concrete under traction, which is why it is built industrially with steel, where it is subjected to compression before being put into use. This type of concrete offers structures more support, reducing the incidence of fissures and cracks.

• Polished concrete: ideal for smoothing surfaces, offering floors that are more resistant to moisture and cracks; it also allows heavy machinery to pass over it without affecting the material.

What advantages does concrete offer compared to other materials?

Concrete is one of the most used materials in construction because it’s considered one of the most advantageous on the market:

• It is easily accessible since its components are commonly available. 
• It can be quickly adapted depending on its structural purposes.
• It lowers the risk of permeability. 
• It has long-lasting durability, thanks to its properties’ qualities. 
• It is ductile and malleable. 
• It’s resistant to heat and, therefore, to warping or collapsing. 
• It has high resistance to compression, bending, cutting, and traction, making it a very safe material. 
• It requires little maintenance.

Is concrete sustainable?

A significant number of structures around the world are made of concrete. Its use is increasingly linked to sustainability decisions, as the material is 100% recyclable, contributes to buildings’ energy efficiency, lowers CO2 emissions and temperature in urban environments, etc. Here are a few of its characteristics:

• Environmentally friendly: concrete can absorb carbon from the atmosphere and reduce the amount of CO2 in the air. This is called the CO2 sink effect, which makes it a leading resource in terms of sustainability. 
• Contributes to global energy efficiency: concrete is a thermal insulator, which allows energy consumption resulting from temperature peaks to be reduced, minimizing the energy cost of buildings and taking part in the reduction of greenhouse gases involved in energy production. 
• High resistance: concrete gives buildings and bridges significant strength when faced with fire or natural phenomena like earthquakes, improving the structures’ service and their level of social security.

Ensures quality of life for residents: concrete can provide high durability for infrastructures, enabling their conservation with low maintenance costs.