The brick is the term it indicates a building material obtained by cooking a clay mixturepossibly improved by adding sand. It is one of the oldest and most widespread materials in construction, used to produce bricks, tiles and tiles and appreciated for its properties of lightness, energy efficiency and durability. Brick combines tradition and technology, finding application in both historic and modern buildings, in which it helps to guarantee controlled energy consumption of the building envelope.
What is meant by brick: the material and its production
Brick (from Latin later“brick”) is an artificial material born from cooking a clay mixture, calcium carbonate (which is often naturally already present in the clay) e waterfall. After the mixing phase, the material is shaped into the desired shape and dried. This is then followed by cooking in the oven at temperatures of approximately 900-1,000 °Cwhich gives the product its typical red colormore or less intense depending on the content of iron oxides, and its mechanical and physical properties: the result is a porous paste with relevant characteristics heat-insulating and sound-absorbing. Its internal structure, characterized by small evenly distributed cavities, also guarantees the brick excellent breathability.
The classification and differences between bricks
The main distinction between the different types of brick concerns the puncture percentagei.e. the quantity of voids compared to the total volume. There direction of these punctures influences the resistance, insulation and placement of the elements. They stand out:
- Solid bricksthat is, those that have a percentage of voids less than 15%. Among these we find the so-called bricks fullfrom the shape standard (25cm x 12cm x 5.5cm). They are mainly employed as load-bearing structural elements. They are in fact suitable for creating masonry walls, arches, vaults and structures with a load-bearing function, albeit for modest loads. However, there is no shortage of applications that outline a more architectural role.
- Semi-solid and perforated bricksare instead all the elements with a percentage of voids greater than 15%. THE half full have punctures up to 45%; the drilled actual exceed 45%. The latter are the most widespread in construction today modernfor a whole series of common applications that we will see in the following examples.
Applications of perforated bricks
In addition to the classification by percentage of voids, it is interesting to observe how each type of brick finds specific applications in the modern construction site, from internal walls to floors. Let’s see some of them:
“Non-structural” walls
Today (perforated) brick is mainly used in the construction of non-load-bearing components of the building envelope, such as:
- External infillsthat is, those walls that separate the interior from the exterior of a building;
- Internal partitionsthat is, those walls used to divide the internal rooms of a building.
In these cases, the element to be used is chosen based on the energy and acoustic performance required by the project. Products of different thicknesses or combinations of layers are used to achieve the desired insulation values.
Load-bearing walls
Although less frequent than in the past, brick can still be used for construction load-bearing wallsespecially in buildings of modest heights.
The limits derive from the low resistance that the product offers compared to the acting stresses, both due to the effect of the weights permanent than in relation to seismic actions. These limitations actually make the material less suitable for the use of reinforced concrete or steel.
Attics
Brick is also used in the construction of atticsi.e. horizontal structures that separate the floors of a building. In fact, when we talk about brick-cement slabwe are referring to a structural element in which the brick acts as a lightening element and disposable formwork, breaking down costs and structural weight. In fact, much is at stake in the different densities of the two materials. For reinforced concrete we have 2500 kg/m³, while the brick approximately 1800 kg/m³. This difference in density allows the creation of lighter floorstherefore optimised, with benefits from a static and economic point of view.
Covers
In the context of roofingbricks are mainly used for the construction of tilesbut there is no shortage of applications for the construction of chimney pots and fireplaces. In the context of tiles, the pairing of tiles (curved brick elements) e roof tiles (flat brick elements) offers the best solution for covering and closing the uppermost levels of a building, guaranteeing the absence of rain infiltrations and offering the right protection from adverse atmospheric agents.
The “porized” variant
In recent years, it has been increasingly developed and used porous brickcharacterized by a lightened mass resulting from the formation of micro-air pockets in the cooking process. This type of brick can weigh up to 25% less compared to the traditional one (1400–1500 kg/m³ versus 1800–2000 kg/m³) and reduces its thermal conductivity by 40%, significantly improving the energy performance of the building in which it is used. Energy efficiency increases, albeit at the expense of one lower mechanical resistancewhich limits its structural use but makes it ideal for high performance infills.
