Concrete Technology and Testing - Aggregate impact value test experiment

1. EXPERIMENT NO 01
AGGREGATE IMPACT VALUE TEST
CONCRETE TECHNOLOGY AND TESTING
NAME : PRABODHA W.M.C.
REG NO : 2018/ET/071
GROUP : 03
DATE : 02/06/2021

2. DATE : 16/06/2021
TITLE : AGGREGATE IMPACT VALUE TEST
AIM/OBJECTIVES :
To determine the aggregate impact value of the given specimen.
NOTATION:
 Milimeter (mm)
 Gram (g)
INTRODUCTION:
Aggregates are one of the most important materials in the field of construction industry. If the
aggregates are weak, the stability of the concrete structure is adversely affected. The strength of coarse
aggregates is assessed by Aggregate Impact Value test. The aggregate impact value provides a relative measure
of resistance to sudden shock or impact.
APPARATUS
1. Aggregate impact testing machine
2. Cylindrical mould
3. Tamping rod
4. IS sieve 12.5, 10 and 2.36 mm
5. Balance 6. Oven
THEORY
Aggregate Impact Value (AIV) is the percentage of fines produced from the aggregate sample after
subjecting it to a standard amount of impact. The standard amount of impact is produced by a known weight,
i.e., a steel cylinder, falling a set height, a prescribed number of times, onto an amount of aggregate of standard
size and weight retained in a mould. Aggregate Impact Values, below 10 are regarded as strong and above 35
are normally regarded as too weak for construction field.
PROCEDURE
• The sample was cleaned by water and cloth to free from dust.
• The sample was dried by oven up to 4 hours.
• Sieve the aggregate sample through 12.5 mm and 10.0mm sieves. The aggregates were passed through 12.5
mm sieve and retained on 10.0mm sieve comprises the test sample.

3. • Weigh the empty measuring cylinder as w1 g. Figure1 : apparatus were setuped of aggregate impact testing
machine
• The aggregates were poured to fill about just 1/3rd depth of measuring cylinder.
• The material was tamp by given 25 gentle blows with the rounded end of the tamping rod.
• Two more layers were added in similar manner, so that cylinder is full.
• Aggregates were striked off the surplus
• The weight of the aggregates were determined with measured cylinder as w2 g.
• The metal cup was fixed firmly in position on the base of machine and lock it to ensure that it does not
oscillate.
• The hammer released of the impact test machine, which falls freely on the sample.
• The test sample was subjected to a total of 15 blows at 1 second interval.
• Weigh the empty sieve size 2.36mm as w4 g.
• The metal cup was removed from the machine & sieve the aggregate through 2.36mm sieve.
• Weigh the sample weight retained in sieve 2.36mm as w5 g.
• The amount was calculated of sample pass through 2.3mm as w3 g.
OBSERVATIONS
No Details
Sample number
1 2 3
1 Weight of empty measuring cylinder = W1 g 970.1 970.1 970.1
2 Weight of aggregate with measuring cylinder = W2 g 1407.7 1384.5 1398.6
3 Weight of empty 2.36mm sieve = W4 (g) 328.6 328.6 328.6
4 Weight of aggregate retained in 2.36 mm sieve with sieve
pan = W5 (g)
557.3 570.6 572.7
5 Weight of aggregate passed through 2.36 mm sieve = W3 g 208.9 172.4 184.4
6 Aggregate Impact value ( % ) 47.74% 41.60% 43.04%
7 Average aggregate impact value 44.13% 44.13% 44.13%
SPECIMEN CALCULATION
Sample 01. Weight of the aggregate sample = 1407.7 – 970.1
= 437.6g
Weight of the aggregate sample = W2-W1

4. Sample 02. Weight of the aggregate sample = 1384.5 – 970.1
= 414.4g
Sample 03. Weight of the aggregate sample = 1398.6 – 970.1
= 428.5g
Sample 01. Weight of the retained aggregate sample = 557.3 – 328.6
= 228.7g
Sample 02. Weight of the retained aggregate sample = 570.6 – 328.6
= 242g
Sample 03. Weight of the retained aggregate sample = 572.7 – 328.6
= 241.1g
Sample 01. Weight of the sample passing through 2.36 mm sieve = 437.6 – 228.7
= 208.9g
Sample 02. Weight of the sample passing through 2.36 mm sieve = 414.4 – 242
= 172.4g
Sample 03. Weight of the sample passing through 2.36 mm sieve = 428.5 – 244.1
= 184.4g
RESULTS
Sample 01. Aggregate Impact Value = 208.9 / (437.6)*100%
= 47.74%
Sample 02. Aggregate Impact Value = 172.4 / (414.4)*100%
= 41.60%
Sample 03. Aggregate Impact Value = 184.4 / (428.5)*100%
= 43.04%
Weight of the retained aggregate sample = W5-W4 g
Weight of the sample passing through 2.36 mm sieve = W3 g = (W2-W1) - (W5-W4) g
Aggregate Impact Value = W3/( W2 − W1) × 100 %

5. DISCUSSION
1.Describe about the application of Aggregate Impact values & state the values used in construction industry.
Application of Aggregate Impact values
The aggregate impact value is a determining measure of resistance to sudden impact or shock, which
may differ from its resistance to gradually applied compressive load.
1.To determine the impact value of the aggregates used in pavement construction(Road);
2.To assess their suitability in road layers (base course, surface course ) construction on the basis of impact
value.
State the values used in construction industry
 Aggregate having AIV % less 50% is better to use in construction where as those having value more than
50% are bad for construction.
 It is reliable to calculate the AIV % of the aggregate use as road construction as it will give us the capacity
of road to bear the load on it. Aggregate having AIV % equal or greater than 35 % is considered bad to
use in road construction.
2. Analyze the result obtained from experiments with the values used in construction industry
 To determine the impact value of the aggregates used in pavement construction(Road);
 To assess their suitability in road layers (base course, surface course ) construction on the basis of
impact value.
CONCLUSION
The tested aggregates are passed to be used in construction work
REFERENCES
https://civilplanets.com/
https://wecivilengineers.wordpress.com/