How is elongation index determined?
Elongation index of an aggregate is the percentage by weight of particles whose greatest dimension (length) is greater than one and four-fifth times (1.8 times or 9/5 times) their mean dimension. It is measured on particles passing through mesh size of 63mm and retained on mesh size of 6.3mm.
How do you determine the flakiness index and elongated index?
The Flakiness Index of aggregates is the percentage by weight of particles whose least dimension (thickness) is less than 0.6 times their mean dimension. The Elongation Index of aggregates is the percentage by weight of particles whose greatest dimension (length) is greater than 1.8 times their mean dimension.
What is the significance of elongation index?
Elongation Index is the percentage by weight of particles in it, whose largest dimension (i.e. length) is greater than one and four-fifths times its mean dimension. Flaky and elongated particles may have adverse effects on concrete and bituminous mix.
Which apparatus is used for determination of elongation?
Elongation Gauge: Used for determination of elongation index of aggregates. It consists of a steel frame having slots of different dimensions.
Why is flakiness test done before elongation test?
Flakiness and Elongation Index Test are very important tests to be performed on aggregate in the laboratory. This test gives the percentage of flaky and elongate aggregate present in the total aggregate sample.
Which apparatus is used for determination of elongation index of aggregates Mcq?
AIM: To determination of Flakiness Index and Elongation Index of Course Aggregates. Apparatus: Standard thickness gauge.
What is the limit of flakiness index?
Flakiness Index of aggregates used in road construction should be less than 15% and normally does not exceed 25%. It is not desirable to use flaky particles in construction of roads especially in surface course.
What is flakiness and elongation test?
What is the most common test used in evaluating soil strength?
California bearing test
What is the most common test used in evaluating soil strength? Explanation: All the tests are performed but the most commonly used one is CBR, which is called as California bearing test, performed in India.
How to find the elongation index?
The elongation index is found by separating the elongation particles and expressing their mess as a percentage of the mass of sample tested. The test is not applicable to material passing 6.30 mm sieve or retained on 50 mm sieve. 4. Page | 4 APPARATUS 1. Length gauge sketch 2. Test sieve size 63mm, 50mm, 37.5mm, 28mm, 20mm, 14mm, 10mm, 6.3mm 3.
What is flakiness and elongation Index test?
Flakiness and Elongation Index Test are very important tests to be performed on aggregate in the laboratory. This test gives the percentage of flaky and elongate aggregate present in the total aggregate sample.
What is the meaning of elongation in tension test?
Elongation is the measure of the ductility of a material that is determined by a tension test. It is the increase in the length gauge of a test specimen after fracture divided by its original length gauge. Higher elongation means higher ductility.
What is the elongation index of aggregates in road construction?
For road constructions elongation index should be less than 15%. For road construction especially in surface course the elongated shape of aggregates is not desirable.