Bulking of Fine Aggregate


Objective: To assess the properties and behavior of the sand grains under different percentage of moisture content

Apparatus

250 ml measuring cylinder, a weighing balance etc.

Procedure

(i) First of all take 500gm (W1) of the aggregate.

(ii) Put the specimen in an oven in a horizontal tray at a very temperature of 100°C-110° C for approximately 24 ± 0.5 hours .

(iii) Now leave the sand for cooling in an air tight vessel and measure its weight(W2).

Water proportion of the specimen= (W1-W2)x 100/W1

(iv) Now take out about 250gm of sand and spread it on the hot pan

(v) Add 2% (by weight) of water and blend them thoroughly.

(vi) Spread the sand specimen into a 250 ml measuring cylindrical vesseal and combine it by the process of shaking.

(vii) Even out the surface and read the volume in ml (Yi).

(viii) Shift the total quantity of sand and continue the test by adding 2% water every time and mark down the parallel volume of sand (Y2,Y3…..) unless the dump sand volume starts to decrease.

(ix) After the completion of this step, add approximately 4% more water every time until the specimen becomes fully saturated.

(x) To the standard sample in the measuring cylinder, Augment approximately 50 ml water ore to the average specimen in the measuring cylinder and thoroughly stir the specimen properly.

(xi) Mark and keep a note of the surface level of inundated sand (Y ml).

Calculations

Bulking =(Y1-Y)x100/Y

Graph

A graph illustated with % water proportion alongside the X-mas and % bulking along Y- axis.

From the graph, choose out the maximum % of bulking happened, % of water proportion at the point of bulking, % of water content when bulking is at the state of zero & % of bulking for the first water content (W) of the specimen.

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

Objective

To assess the required adjustment for the bulking of the fine aggregates in field

Apparatus

250 ml measuring cylindrical vessel

Procedure

(I) Discharge the dump sand in to a 250 ml measuring cylindrical vessel up to the 200 ml measurement.

(II) Fill the cylinder with water and stir well (sufficient water should be poured to partially immerse the sand totally and we can see that the sand surface is now lesser than its initial 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=