Bricks are one of the most widely used building materials, which have been in use for millions of years. They are primarily used for the construction of walls, pavements, foundations, and other masonry work. Over the years, there have been several types of bricks in the market and each of them differs in properties and applications. Here we take a look at what are the properties of the bricks, what characteristics a good brick possesses and what are the properties of engineering bricks.
What are the properties of bricks?
The properties of bricks vary based on the types and manufacturing, which describe the looks, strength, and capabilities of the bricks. The most important properties of bricks are generally grouped as physical properties, mechanical properties, and structural properties.
Physical Properties
Size and dimensions
The bricks should be rectangular and must have sharp and straight edges. The size of the bricks should be uniform in shape and must follow the IS standard size of 190 x 90 x 90 mm or 190 x 90 x 40 mm(19 x 9 x 9 cm or 19 x 9 x 4 cm).
Weight and Density
According to Indian Standards, the ideal weight of the bricks should be between 2.5 to 3.5 kilograms. The bricks are usually dense and the weight varies based on the type of raw materials used and the type of brick molding. The standard density of bricks varies from 1600 kg/m³ to 2000 kg/m³.
Colour and Appearance
The general colour of any clay brick is red and should have uniform colouring throughout the brick. The quality of the clay, pigments, and the burning of bricks play a major role in determining the colour of the bricks. Although bricks are generally red, some bricks are available in different colours including white, orange, grey, black, blue, and more.
Texture and Surface Characteristics
Bricks should have a uniform texture and solid surfaces with sharp edges and straight sides. There should be no cracks or cavities in the structure, making it more smoother.
Mechanical Properties
Resistance against compression
This property shows how strong a brick is when pressure or weight is applied to it. It tells us how much load a brick can handle without breaking. The strength of a brick depends on the type of clay used and how well it is fired in the kiln. Different types of bricks have different levels of compressive strength, usually ranging between 35 kg/cm² to 100 kg/cm². Bricks that can handle more pressure are ideal for building structures that need to support heavy loads.
Tensile Strength
It determines the maximum load a brick can support when stretched or split without breaking. The tensile strength of the bricks varies from one brick type to another. The average tensile strength of a brick is 2.5 MPa.
Impact Resistance
The brick when dropped at a height of 1 meter onto a hard surface, should not develop a crack or break. Bricks that develop cracks or breaks have low impact value and are not suitable for construction work.
Hardness
The brick is scratched on the surface with metal to check the hardness. The abrasion should not leave any impression or marks. If the brick has any scratch marks or cracks, it means that the brick is of poor quality.
Structural Properties
Durability
The durability of the bricks determines how long the brick can last while remaining intact when used in the construction. Generally, bricks are employed in almost every building project, which makes the structure stand longer. Bricks that are hard, dense and can withstand any external stress have high durability.
Water Absorption
The bricks are immersed in water for 24 hours, and their water absorption rate is measured. An ideal brick should not absorb water that exceeds 20% of its body weight. The lower the weight it gains after immersing in water, the lower the water absorption rate.
Weathering Resistance
The bricks that are used in external structures have to be adaptable to all kinds of weather conditions. Bricks that are dense, less porous, free from cavities, have a low efflorescence rate and are insulated from fire have good weathering resistance and can be applicable for almost all types of structures.
Fire Resistance
Bricks should have low thermal conductivity so that they can withstand high temperatures and maintain a warm temperature within the structure. Clay and sand are the key materials responsible for the fire resistance properties. Bricks that are highly dense and burned in the kiln under high temperatures have high fire resistance.
Sound Insulation
Bricks that are dense and heavy have poor sound insulation, whereas hollow bricks and shale provide good sound insulation and can be applied to places where external noise cancellation is crucial.
What are the properties of Good Bricks?
Choosing a good brick for your dream construction is crucial. Here are some of the quality indicators that determine the properties of a good brick.
Quality Indicators
No Cracks or Flaws: The bricks should not have any cracks, cavities, or large pore holes in the structure.
Free from Organic Matter: The clay and sand used for the manufacturing of bricks should be free from vegetable wastes, roots, and other organic matter. They should also be free from pebbles and stones.
Proper porosity: The bricks should have less or no large pore gaps. Bricks that have high pore holes are weak, absorb more water, promote crystallisation, and develop cracks.
Adequate density: The bricks should have adequate density so that they can bear the load. The density of the brick depends on the types of clay used, tempering, and tight molding process. An ideal brick should have a density between 1600 kg/m³ to 2000 kg/m³.
Uniform Texture: The bricks should have a uniform smooth texture, free from any undulations and cracks. Bricks that have uneven edges and powdery surfaces are not suitable for construction.
What are the Properties of Engineering Bricks?
Engineering bricks are high-quality bricks that have high strength and resistance against heavy loads, heat, and other chemical reactions. Here we take a look at the properties of engineering bricks.
High Strength
These bricks have high resistance to compression ranging from 75 N/mm² to 125 N/mm², which is higher than other clay bricks.
Excellent resistance to water
Engineering bricks have a water absorption rate of less than 7%, which is lower than other brick types. The high water resistance property prevents the structure from external moisture, rainfall, and water penetration.
Chemical attack
Engineering bricks have high resistance to chemicals such as acids and alkalis, preventing the structure from all kinds of chemical attacks and weather conditions.
Durability
Engineering bricks can last for a long period of time as they can withstand any internal and external stresses.
Conclusion
In summary, a good brick should possess all the physical, mechanical, and structural properties and should follow the Indian Standard shape and composition. The key elements of the bricks are the raw materials used, the manufacturing process, their appearance, and their mechanical and structural properties. Choose the right bricks for your dream house or other commercial properties, keeping these qualities in mind.