WATER ABSORPTION TEST

Water Absorption Test is used to find out the water absorption ratio. Because the brick, which are absorbing more water cannot be used in water logging area or exterior walls which is open to sky. The bricks from all the proportion were tested. The following steps were followed to find out the water absorption ratio.

o   First all the bricks were weighed in a electronic weighing machine. This weight was noted as W1.

^o     Then all the bricks were placed in an oven. Then the temperature in the oven was set at the temperature of 105^·C

o   After 24 hours the bricks were taken out and weighed. This weight was noted as W2

o   Then bricks were allowed to cool in a room temperature.

o   After that the bricks were immersed in water for 16 hours.

o   After 16 hours the bricks were taken out and wiped with cloths. Then the bricks were weighed. This weight was noted as W3

o   Then the water absorption ratio was calculated by this formula.

Water Absorption Ratio =[ (W3-W2)/W2] *100

The following table gives the water absorption ratio of different bricks.

        Water absorption ratio of fibrous concrete bricks

S.no	Mix	Dry weight, W2 (Kg)	Wet weight, W3 (Kg)	Water absorption ratio (%)
1	M1	0.841	1.658	97.15
2	M2	0.677	1.560	130.43
3	M3	1.543	1.994	29.22
4	M4	1.527	2.187	43.22
5	M5	1.992	2.626	31.82
6	M6	1.472	2.258	53.39
7	M7	1.000	1.820	82
8	M8	0.801	1.380	72
9	M9	0.676	1.300	92
10	M10	1.582	2.680	69.40

Water absorption ratio for Padobe Brick

S.no	Mix	Dry weight, W2 (Kg)	Wet weight, W3 (Kg)	Water absorption ratio (%)
1	M11	1.956	2.249	14.98

Water absorption chart

As per standard, the bricks should not absorb water more than 20% of its weight, but from the table 8 &9 results, bricks exceeded water absorption ratio more than 20%. In this, the mix that contains only paper and cement absorbs water more than its weight. And the mixes that were mixed in 1:3:6 ratio absorbed more water. So these bricks are not suitable for water logging and exterior walls. These bricks can be used for interior partition walls only. But the padobe bricks absorbed water only 14.98%.So the padobe  bricks are suitable for all types of construction and it can be used for water logging areas, exterior walls etc.,