Highway Elongation Test

EXPERIMENT : 1

TOPIC : ELONGATION TEST

OBJECTIVE : To determine suitable elongation aggregate for pavement.

APPARATUS : 1. Sieve 2. Elongation equipment 3. Tray 4. Scale weight 5. Sieve vibrator

MATERIAL : 2000g aggregate.

PROCEDURE 1. Deliberate 2000g sample of aggregate.

2. Size of sieve :- 6.3mm,10mm,14mm,20mm,28mm and 37.5mm

3. Get the weight of plain sieve (a)

4. Put the aggregate into the sieve and vibrate it for 10 minutes.

5. After vibrate get the value of weight of plain sieve + aggregate (b)

6. Record the mass in gram. (b – a = c) [ M1 ]

7. Get the percentage of retained aggregate ( c / M1 x 100% )

8. Mass balance after discharge mass less than 5% ( M2 )

9. Use elongation equipment to get suitable size for this test

10. Mix the particle and deliberate elongation mass [ M3 ]

ELONGATION INDEX = M3 / M2 X 100 |

RESULT :

Sieve | a | b | c | % | Mass balance(g) | 6.3 | 1.020 | 1.118 | 98 | 98 /1992x100 = 4.92 | 0 | 10.0 | 1.023 | 1.658 | 455 | 455 /1992x100= 22.8 | 455 | 14.0 | 1.132 | 2.428 | 1296 | 1296 / 1992 x100= 65 | 1296 | 20.0 | 1.399 | 1.542 | 143 | 143 /1992x100= 7.18 | 143 | 28.0 | 1.502 | 1.502 | 0 | 0/1992x100 = 0 | 0 | 37.5 | 1.488 | 1.488 | 0 | 0/1992x100 = 0 | 0 | TOTAL | | | M1 = = 1992 | | M2 = 1894 |

M3 = 1.183

Elongation = 1183 / 1894 x 100 = 62.46%.

QUESTION :

1. Discuss how the shape and elongation of the rock can effect the strength.

* Aggregate shape, texture and grading have a significant effect on the performance of fresh concrete. Aggregate blends with well-shaped, rounded ,and