Question

please write for me an INTRODUCTION ( in detail ) about Sieve Analysis of Aggregates .

Please use Computer Font.

Answer 1

Introduction:

Sieve Analysis is distribution of particle sizes expressed as a percent of the total dry unit weight.Sieve Analysis also called as Aggregate Gradation.Gradation,which is by passing the material through a series of sieves stacked with small openings from top to bottom and weighing the material retained on each sieve.

Most probably in graduation level, we studied the sieve sizes from 12.5 mm to 75 microns.Above sieve sizes also there but we particularly concentrated on above mentioned sieves only.The following are sieve sizes 12.5 mm,10 mm,4.75 mm,2.36 mm,1.16 mm,600 microns,300 microns,150 microns,75 microns.

In Aggregates,basically divided as(a) coarse aggregate ,(b) fine aggregate.

(a)Coarse aggregate:All the materials(Aggregates) retained on and above 2.36 mm sieve are called as coarse aggregates.\

(b)Fine Aggregate:All the materials passing on 2.36 mm sieve is called as fine aggregates.

There are two methods in Sieve analysis.

(i)Dry Sieve Analysis

(ii) Wet Sieve Analysis

For any method we must prepare sample(Aggregates) from the original sample.because for coarse aggregates we have to do the experiment by lifting the weight on our hands.Of course for fine aggregates also same process,but the weight is the point here.This is like a precaution.

Dry Sieve analysis:

We arrange the sieves in decreasing order from 12.5 mm above and below 75 microns. First we calculate the weight if the total sample and pour the aggregates on 12.5 mm sieve and lift the total sieves on pair of hands.then we have to move the sieves in zigzag motion.All the smaller particles passed through sieves.do the experiment for 10 mins and open the all sieves and weigh the aggregates of each sieve and note down the weight on paper with resp sieve.

Total Wt of Aggregates:1Kg

1	%of weight retained	%of passing	cummlative wt reatined

We have note down all weights in tabular form.

Cummulative % retained =

(% Wt retained on that sieve /Total wt of sample)*100

Cummulative % passing =

100- % retained

Like that we calculate every sieve.

Percentage of passing and retained is used for differnentation of many aggregate properties.

Wet sieve analysis same but the sameple is wet sample we have to take.