AIM
To study the behaviour of sand grains under varying percentage of moisture content .
APPARATUES.
250 ml measuring cylinder ,weighing balance etc .
PROCEDURE
(i) Take 500gm (W1) of the aggregate.
(ii) Keep the sample in an oven in a tray at a temperature of 100°C-110° C for 24 ± 0.5 hours .
(iii) Cool the sand in an air tight container and weight it (W2)
Water content of the sample = (W1-W2)x 100/W1
(iv) Take out about 250gm of sand and pour it into a pan.
(v) Add 2% (by weight) of water and mix well.
(vi) Pour the sand sample into a 250 ml measuring cylinder and consolidate by shaking.
(vii) Level the surface and read the volume in ml (Yi).
(viii) Take out the whole quantity of sand and continue the experiment by adding 2% water more each time and note the corresponding volume of sand (Y2,Y3…..) until the dump sand volume starts decreasing.
(ix) Beyond this point, add 4% more water each time until the sample become fully saturated.
(x) To the standard sample in the measuring cylinder, add about 50 ml water ore and stir the sample well.
(xi) Note down the surface level of inundated sand (Y ml).
CALCULATIONS
Bulking =(Y1-Y)x100/Y
GRAPH
A graph drawn with % water content along X-mas and % bulking along Y- axis.
From the graph, pick out maximum % of bulking occurred, % of water content at maximum bulking , % of water content When bulking is zero & % of bulking for the initial water content (W) of the sample.
RESULTS
% of bulking occurred =
% of water content at maximum bulking=
% of water content when bulking is zero=
% of bulking for the initial water content (W) of the sample =
FIELD TEST FOR BULKING OF FINE AGGREGATES
AIM
To determine necessary adjustment for the bulking of fine aggregate, in the field.
APPARATUES
250 ml measuring cylinder
PROCEDURE
(I) Pour the dump sand in to a 250 ml measuring cylinder up to the 200 ml mark.
(II) Fill the cylinder with water and stir well (sufficient water should be poured to submerge the sand compleately and it can be see that the sand surface is now below its original level)
(III) Take the reading at the sand surface (Y ml)
CALCULATIONS
% of bulking { (200/Y)- 1] x100
Report the percentage bulking of the sand to the nearest whole number.
RESULT
Percentage bulking of field sample=