Question

CIVIL ENGINEERING AGGREGATE TEST LAB REPORT (ESSAY)

2.3 Specific Gravity for Fine Aggregates
2.3.1 Objective
2.3.2 Scope
2.3.3 Apparatus
2.3.4 Test Procedure
2.3.5 Test Result

these are the topics.  Please use computer font.

Answer 1

Solution -

2.3 - Specific Gravity of Fine Aggregate - It is the raytio of the weight if given volumne of aggregate to the weight of equal volume of water.

2.3.1 - Objective - This test covers the procedure for determining the specific gravity of fine aggregate.

2.3.2 - Scope - Specific gravity test is done to measure thye strength or quality of the material.

2.3.3 - Apparatus-

1. A balance of capacity not less than 3kg , readable and accurate to 0.5gm and of such a type as to permit the weighing of the vessel containing the aggregate and water.
2. A well ventilated oven to maintain a temperature pf 100oC to 110oC.
3. Pycnometer of about 1 litre capacity ghaving a metal conical screw top with a 6mm hole at its apex. The screw top shall be watertight.
4. A means supplying a current warm air.
5. A tray of area not less than 32cm2
6. An airtight container large enough to take the sample.
7. Filter papers and funnel.

2.3.4 - Procedure of Test;

1. Take about 500g of sample and place it in the pycnometer.
2. Pour distilled water into it until it is full.
3. Eliminate the entrapped air by rotating the pycnometer on its side, the hole in the apex of the cone being covered with a finger.
4. Wipe out the outer surface of pycnometer and weight (W)
5. Transfer the contents of the pycnometer into a tray , care being taken to ensure that all aggregate is transferred.
6. Refill the pycnometer with distilled water to the same level.
7. Find out the weight (w1)
8. Drain water from the sample through a filter paper.
9. Place the sample in oven in a tray at a temperature of 100o to 110oC for 240.5 hours. , during which period it is stirred occasionally to facilitate drying.
10. Cool the sample and weight it (W2).

Calculation - Apparent Specific gravity = (weight of dry sample/weight of equal volume of water)

= W2/(W2-(W-W2))

2.3.5 - Results - Parameter measured ;

1. Fine aggregate bulk specific gravity.
2. Fine aggregate bulk SSD specific gravity.
3. Fine aggregate apparent specific gravity.
4. Fine aggregate absorption.