5-Hour Boiling Water Test

The specimen is dried within an oven at 105 to 115^oC till it attains constant mass. At room temperature cool the specimen and record its weight (W₁). The brick is immersed in boiling water for 5 hours. The water is permitted to cool at 27 ± 2^oC with brick immersed. The brick is taken out and wiped along with damp cloth. Full the weighing of the specimen in three minutes. Now let it be W₃.

Water absorption, percent by mass, is given through

W₃   - W₁/ W₁ × 100