To determine the “Water Absorption” percent by mass of Burnt Clay Bricks.

To Determine the “Water Absorption” Percent by Mass of Burnt Clay Bricks.

INTRODUCTION

Bricks are used in building members such as walls, roofs, and foundations. These members are heavily subjected to water in the form of rain or water coming from the water table. These bricks need to be able to resist the water and not allow access inside it. This test is intended to know about finding the water absorption of the bricks.

IMPORTANCE OF WATER ABSORPTION TEST:

MATERIALS REQUIRED:

• Bricks, Water

APPARATUS REQUIRED:

• Weighing machine, bowl, piece of damp or cotton cloth, and thermostatically controlled oven.

THEORY:

Water Absorption: It is defined as the amount or percentage of water absorbed by the brick. Water absorption depends upon the porosity of the brick. A good brick does not absorb water greater than one-seventh of its weight. Therefore a brick is to be tested to see whether it absorbs water according to the standard or not, if it is, then the brick is suitable for constructional purposes. If it absorbs more than according to the standard then the brick is not suitable for construction work because in this case its strength is decreased. Hence the brick becomes less suitable.
The dry specimen is put in an oven maintained at a temperature of 110+5°C. Till it attains substantially constant mass. The weight of the specimen is W1 then after cooling it at room temperature this is immersed completely in water for 24 hours. Take the specimen and wipe out all the traces of water with a damp cloth. And then weigh the specimen. Let this weight be W2. The percentage is calculated by:
Percentage of water absorbed =((W2-W1) / W1 ) x 100

Water Absorption:

Procedure.

1. Take a brick and put it in the oven under the temperature of 110+5°C to remove the water present in it.
2. Leave the brick in water for 24 hours.
3. After 24 hours take the brick out and weigh it.
4. This brick is called the oven-dried brick. And it is denoted by W1.
5. Put the brick in a bowl filled with water for 24 hours.
6. After 24 hours take it out and dry its surface with the damp cloth. This condition is called the Surface Saturated Dry (S.S.D) condition.
7. Note the weight of the brick in S.S.D condition. This weight is called the S.S.D weight and is denoted by W2
8. Use a formula to find out the percentage absorption.

Observations:

Observations:

The percentage of the water absorption of Sample No.1 is and the percentage of the water absorption of Sample No.2 is.

Review Questions

1. What is the Porosity of bricks?
2. Are the above-tested bricks suitable for good construction work? Justify your answer
3. Why the temperature of Oven is kept between 105⁰ C and 110⁰ C