DETERMINATION OF ELONGATION INDEX                                                                       ( IS : 2386 PART – 1 ) – 1963

PROCEDURE : -

SIEVING – THE SAMPLE SHALL BE SIEVED IN ACCOREDANCE WITH THE MOTHOD DESCRIBED IN 3 WITH THE SIEVES SPECIFIED IN TAVLE V  

SEPARATION OF ELONGATED MATERIAL -   EACH FRACTION SHALL BE GAUGED INDIVIDUALLY FOR LENGTH ON A METAL LENGTH GAUGE OF THE PATTERN .  THE GAUGE LENGTH USED SHALL BE THAT SPECIFIED IN COL 4 OF TABLE V FOR THE APPROPRIATE SIZE OF MATERIAL

WEIGHING ELONGATED MATERIAL -  THE TOTAL AMOUNT RETAINED BY THE LENGTH GAUGE SHALL BE WEIGHED TO AN ACCURACY OF AT LEAST 0.1 PERCENT OF THE WEIGHT OF THE TEST SAMPLE .

TABLE (V ) DIMENSIONS OF THICKNESS AND LENGTH GAUGES                                                                                                         

SR. NO.	SIZE OF AGGREGATE		THICHNESS    GAUGE	LENGTH GAUGE
	PASSING THROUGH IS  SIEVE       ( 1 )	RETAINED ON IS SIEVE          ( 2 )	( 3 ) MM	( 4 ) MM
1	63 – MM	50- MM	33.90	--
2	50- MM	40- MM	27.00	81.0
3	40- MM	25- MM	19.50	58.5
4	31.5- MM	25- MM	16.95	---
5	25- MM	20- MM	13.50	40.5
6	20- MM	16 - MM	10.80	32.4
7	16- MM	12.5- MM	8.55	25.6
8	12.5-MM	10 -MM	6.75	20.2
9	10- MM	6.3- MM	4.89	14.7
10

   REPORTING OF RESULT -  THE ELONGATION  INDEX   IS THE TOTAL WEIGHT  OF THE MATERIAL RETAINED  ON THE  VARIOUS  LENGTH  GAUGES EXPRESSED AS A PERCENTAGE OF THE TOTAL WEIGHT OF THE SAMPLE GAUGED .