One of the key reasons that some facades remain operational for generations with no cracks or leaks developing on them over time is the water absorption of bricks. Bricks form the cornerstone of robust buildings, but the water absorption tendency of bricks may affect their durability, strength, and quality. Bricks with minimum water absorption favor good mortar bonding, but more water absorption pervades water inside the bricks, which leads to compromised structures.
Selecting the appropriate bricks for a durable building requires an understanding of how they react with water. In this Brick & Bolt article, we will explore water absorption and other essential details to help you understand the essential factors while constructing your building.
What is Water Absorption in Bricks?
When you soak the bricks in water for a particular duration, the quantity of water that can be absorbed by these bricks is known as water absorption in bricks. Water absorption in bricks is an important parameter that decides the quality and strength of a building constructed using bricks, concrete, and other materials. The water absorption property of a brick should be inspected for various classes of bricks, like first class, second class, or third class.
Why is it an Important Factor in Construction?
Some reasons why water absorption is important to consider are as follows:
Strength and Resilience:
When bricks absorb high water content, they can crack, spall, and disintegrate under freeze-thaw conditions. To prevent brittle and porous bricks in the long run, utilise low water-absorbing bricks for constructing buildings based on their increased strength and permanence.
Thermal Insulation:
Bricks with low water absorption don’t conduct heat from the outside environment to the inside house. So, it keeps the room cooler in high temperatures with its low absorption properties. On the other hand, high water absorption bricks it increase heat and leads to crack and other damages.
Aesthetic Appeal:
Low water absorption bricks maintain their colour and appearance over the years, enhancing the beauty of the building. But bricks with excessive water absorption quality may discolour and fade over time.
Procedure for Water Absorption Test
The water absorption test is used to observe and check the quality and endurance of the bricks used to build structures. A brick that absorbs less than 7% water resists damage from freezing. Bricks with more pores absorb more water, making them weaker. Bricks that absorb less than 3% water are vitrified and very strong. This test helps measure the percentage of water absorption in bricks.
Apparatus
- A weighing scale that measures accurately.
- A ventilated oven for drying the bricks.
Specimen
- Three bricks are selected for testing.
Procedure
- Dry the bricks in an oven at 105 – 115° C until they do not gain or lose weight.
- Let the bricks cool down to room temperature and measure them (M1).
- Immerse the bricks in clean water (27°C) for 24 hours.
- Take away the bricks, dry off any excess water, and reweigh them (M2).
The variation between M1 and M2 indicates the extent to which the brick absorbs water, assisting in defining its strength and long life.
Calculation of Water Absorption of Bricks
The water absorption percentage of a brick after 24 hours of immersion is calculated using the formula:
Water Absorption= (M2-M1)/M1 × 100
Where,
M1 =Dry weight of brick
M2 = Wet weight of brick
Let’s see the Example Calculation
Let’s assume:
M1 (Dry weight of brick) = 2000 g
M2 (Wet weight of brick) = 2200 g
Water Absorption = 2200 − 2000 / 2000 × 100
Water Absorption =10%
Result
The water absorption of the given brick = 10%
A brick with absorption below 7% is high quality, while absorption above 20% indicates poor quality.
The test result recommendations for different classes of bricks are as follows:
- For first-class bricks, it should not be more than 15 %
- For second-class bricks, it should not be more than 20 %
- For third-class bricks, it should not be more than 25 %
Effect of High Water Absorption on Bricks
- Bricks that absorb a lot of water may disintegrate over time.
- When bricks absorb too much water, they become prone to erosion and cracking and cause structural damage.
- Because absorbed water freezes and expands in cold climates and results in breaking.
- The high water absorption of bricks erodes not only walls but also the mortar-brick connection.
- Excessive moisture reduces the lasting permanence of bricks and their appearance by causing efflorescence (white salt deposits), mould growth, and dampness.
- Structures built of poor-quality bricks with high absorption rates deteriorate with time and become more susceptible to damage.
How to Reduce Water Absorption in Bricks?
Water absorption in bricks can be effectively managed by following the below steps:
Use Well-Burnt Bricks:
- Use well-burnt bricks because when bricks are fired at the right temperature, they have fewer pores and absorb less water.
Choose High-Quality Clay:
- Bricks with dense, fine-grained clay absorb less water.
Apply Water-Proof Coatings:
- While doing painting works, applying a waterproof coating over the bricks can shield them from moisture.
Check for Water Absorption Before Use:
- Always test bricks and choose those with an absorption of less than 7% for strong structures.
Use the Appropriate Curing Methods:
- Bricks that are properly cured are stronger and more durable.
Store The Bricks In Dry Areas:
- Before starting your construction process, keep your bricks properly in dry places to avoid intact with water.
Conclusion
In summary, water absorption is a vital factor to determine the strength, endurance, and quality of the brick. Bricks that are available with low water absorption ensure strong bonding with concrete and resistance to changing weather conditions. The structural integrity of the building can be enhanced while using low water absorb bricks.
High water absorption bricks in construction lead to cracks and high structural damage. You need to invest wisely in selecting the right building materials before starting any construction work. At Brick & Bolt, our team of experts must do the testing procedures and initiate their construction. We follow strict quality checks and use well-tested bricks to construct your dream home. For expert guidance, call our team today and get a free quotation.
Mithali Konety