Clay bricks are some of the most widely-used building materials. These can be used for a variety of domestic and commercial applications; some of the most common uses for clay bricks include walls, roofs, terraces, garden spaces and façades. Recent improvements in brick manufacturing have allowed bricks with increased voids to be introduced, with the voids providing comparable performance in their flexural bond strength and water resistance. With many brick manufacturers wanting to reduce the number of resources used in the process, they adopt a very economical and practical approach to manufacturing clay bricks for exterior walls of a building structure.
Types of Clay used in bricks for exterior walls of a building structure
Clays occur in three principal forms, all of which have similar chemical compositions but different physical characteristics.
Surface Clays- Surface clays may be the upthrusts of older deposits or more recent sedimentary formations. As the name implies, they are found near the surface of the earth.
Shales- Shales are clays that have been subjected to high pressures until they have nearly hardened into slate.
Fire Clays- Fire clays are usually mined at deeper levels than other clays and have refractory qualities.
Surface and fire clays have a different physical structure from shales but are similar in chemical composition. All three types of clay are composed of silica and alumina with varying amounts of metallic oxides. Metallic oxides act as fluxes promoting fusion of the particles at lower temperatures. Metallic oxides (particularly those of iron, magnesium, and calcium) influence the color of the fired brick. The manufacturer minimizes variations in chemical composition and physical properties by mixing clays from different sources and different locations in the pit. Chemical composition varies within the pit, and the differences are compensated for by varying manufacturing processes. As a result, brick from the same manufacturer will have slightly different properties in subsequent production runs. Further, brick from different manufacturers that have the same appearance may differ in other properties.
Stages of clay brick manufacturing-
● Size reduction
● Forming and cutting
● Coating and glazing
● Firing and cooling
Advantages of clay bricks for exterior walls of a building structure
Clay bricks are some of the most widely-used building materials. These types of handmade bricks can be used for a variety of domestic and commercial applications; some of the most common uses for clay bricks include walls, roofs, terraces, garden spaces and façades, but it really doesn’t stop there. Clay bricks can be used for a wide range of purposes due to their incredible properties.
Recent improvements in brick manufacturing have allowed bricks with increased voids to be introduced, with the voids providing comparable performance in their flexural bond strength and water resistance. With many brick manufacturers wanting to reduce the number of resources used in the process, they adopt a very economical and practical approach to manufacturing clay bricks. Some of its advantages are-
Versatile – Clay building materials can be used for a variety of applications. They can be used for walls, façades and roofs as well as for gardens, terraces and open spaces. Clay tiles and bricks can be used almost anywhere and for all architectural styles, whether for the construction of single family houses or apartment blocks, office or public buildings.
Energy-efficient – Owing to their excellent insulation properties and their heat storage capacity clay building materials help to reduce the energy consumption of buildings.
Durable – Clay building materials are robust, stable and, as a result, especially durable; their lifespan is more than 100 years. Brick buildings, which have lasted for centuries, can be discovered all around the world. Buildings made of clay tiles and bricks are weather-resistant, earthquake-proof and fire-resistant.
Aesthetic – Clay bricks and tiles are aesthetic and versatile. Thanks to a wide range of available colours, shapes and surfaces, the number of possible designs and variations is almost unlimited. The colour spectrum ranges from super white to classic red to coal-black. Available variants include rough, smooth and glazed surfaces, elongated and wide formats. Roof tiles and facing bricks as well as pavers can be perfectly coordinated with one another.
Economic – A solid building envelope made of brick can be constructed quickly and flexibly – this saves both time and money. Wind and weather, heat and frost are not able to damage clay building materials. As a result, maintenance and service costs are low. Owing to their favourable insulation properties, clay building materials also help to save energy costs.
Natural materials – Clay blocks, facing bricks and clay roof tiles as well as pavers are particularly sustainable and natural building materials because they consist of the natural raw materials clay and water. Bricks and tiles are absolutely free of pollutants and allergens and thus especially compatible with humans and nature.
Larger value – Even after many years, buildings made of clay building materials retain their value – or it even increases. Owing to their durability, stability and special living quality, brick buildings and apartments are in great demand and achieve high resale values. Furthermore, bricks and tiles are easy-to-clean and low-maintenance.
How is the load-bearing capacity of clay bricks for exterior walls of a building structure?
Clay bricks have long been used as extraordinary load-bearing construction materials. Clay facing bricks also perform well in terms of load-bearing, shadow effect, and color intensity. With clay facing bricks, reasonable structural beauty can be achieved utilizing shade or vertical grain that results from the installation process, the thickness of jointing, and unevenness of bricks; different color belts or patterns (also called “secondary texture) can be created utilizing interspersion, inlay, etc.; different architectural style can be formed when used together with other materials such as glass, glass bricks or cement bricks. Through the bricks’ dimensions, surface texture, granular gap and irregularity, clay facing bricks bring a kind of visual effect that can not be seen on the smooth and regular metals or glass, both of which are products from modern technology.
Both compressive strength and absorption are affected by properties of the clay, method of manufacture and degree of firing. For a given clay and method of manufacture, higher compressive strength values and lower absorption values are associated with higher firing temperatures. Although absorption and compressive strength can be controlled by manufacturing and firing methods, these properties depend largely upon the properties of the raw materials.
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