Flakiness and Elongation Index of aggregate|with calculation
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- Опубліковано 3 лют 2019
- flakinessandelongationindexhindi#flakinesstestofagregateogpcwmmdbmbcsdbc#testforaggregate#rahullab#ce<
FLAKINESS AND ELONGATION INDEX OF AGGREGATE
1. Objective
Particle shape and surface texture influence the properties of freshly mixed concrete more than the properties of hardened concrete. Rough-textured, angular, and elongated particles require more water to produce workable concrete than smooth, rounded compact aggregate. Consequently, the cement content must also be increased to maintain the water-cement ratio. Generally, flat and elongated particles are avoided or are limited to about 15 % by weight of the total aggregate.
2. Apparatus Required
Fig. 1: Balance
Balance should be able to weigh upto 1 g.
Fig. 2: Sieves
Sieves required are 63, 50, 40, 31.5, 25, 20, 16, 12.5, 10 and 6.3 mm (Based on requirement and Gradation of Aggregate).
Fig. 3: Thickness Gauge- For Flakiness Index
Thickness Gauge have width equal to 0.6 times the mean dimension of the aggregate.
Fig. 4: Length Gauge- For Elongation Index
Length Gauge have length equal to 1.8 times the mean dimension of the aggregate.
3. Reference
IS 2386(Part 1):1963 Methods of Test for Aggregates of Concrete- Particle Size and Shape. Reaffirmed- Dec 2016
4. Procedure
A quantity of aggregate shall be taken sufficient to provide the minimum number of 200 pieces of any fraction to be tested.
The sample shall be sieved with the sieves specified in Table 1:
Size of Aggregate thickness (mm)Thickness Gauge * (mm)Length Gauge ** (mm)Passing through IS SieveRetained on IS Sieve635033.90-504027.0081.0402519.5058.531.52516.95-252013.5040.5201610.8032.41612.58.5525.612.5106.7520.210.06.34.8914.7
* This dimension is equal to 0.6 times the mean Sieve size
** This dimension is equal to 1.8 times the mean Sieve size
Table 1 : Dimensions (Length and Thickness) of Gauges
Separation of Flaky material- Each fraction shall be gauged in turn for thickness on a metal gauge of the pattern shown in Fig. 3, or in bulk on sieves having elongated slots. The width of the slot used in the gauge or sieve shall be of the dimensions specified in co1. 3 of Table 1 for the appropriate size of material.
The total amount passing the gauge shall be weighed to an accuracy of at least 0.1 percent of the weight of the test sample.
The Flakiness Index is the total weight of the material passing the various thickness gauges or sieves, expressed as a percentage of the total weight of the sample gauged.
Separation of Elongated Material- Each fraction shall be gauged individually for length on a metal length gauge of the pattern shown in Fig. 4. The gauge length used shall be that specified in co1. 4 of Table 1 for the appropriate size of 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.
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.
5. Observation And Recording
Passing through IS Sieves(mm)Retained on IS Sieves (mm)Flakiness Gauge (mm)Weight Passing on Flakiness Gauge (g)Percentage Weight Passing (%)635033.90504027.00402519.5031.52516.95252013.50201610.801612.58.5512.5106.75106.34.89Total
Table 2 : Recordings for Flakiness Index
Passing through IS Sieves(mm)Retained on IS Sieves (mm)Elongation Gauge (mm)Weight Retained on Elongation Gauge (g)Percentage Weight Retained (%)6350--504081.00402558.53125--252040.50201632.41612.525.612.51020.2106.314.7Total
Table 3 : Recordings for Elongation Index
6. Calculation
The Flakiness Index on an aggregate is =
Total weight passing Flakiness Gauge x 100 / Total weight of test sample =_________(%)
The Elongation Index on an aggregate is =
Total weight retained on Elongation Gauge x 100 / Total weight of test sample =________(%) - Наука та технологія
very useful video sir thanks for your promise
Thank u sir very helpful video.☺️
Helpful videos NYC
Superb, thank you
Nice sir ✅
Nice video
Thanks for your video bhai ...mera pracricle exam k lie aapka video bohot helpful rehega
Ek bar Cobmine fi & Ei test ka CALCULATIONS bhi jarur dekh lena...
सुपर सर
Nice
Thanks for this video CBR test full process ka video bnao sirji
It's very thankful for is
In video you write defination of elongated aggre. is 4/5 or 0.8 vlaue...it actually greater aggregate is 9/5 or 1.8 of is greater dimension aggregate
Thanks for making the video
Thanks dear...Help to share my channel to your others friends and groups...
Elongatetion mean size should be 9/5 or 1.8
Tysm sir
Thansk you 💖
👍
9/5
Plz Sir make video of OGPC Binder content test with details calculation sheet. I need your help. Plz Sir help me.
Sir.. what is mean dimension ?
Plzz explain
Tahnkujisar😊😊😊😊
Sir agar combined ho to phir kese karna pare ga us ki koi video hai toh link mentioned karo
ua-cam.com/video/JSxib7Su76k/v-deo.html
@@HIGHWAYENGINEERING thanks sir
1.8 times
Sir, flankiness ka retained weight wrong h apka
Gsb grade 3 k liye ??
Kyu ham 1st flakiness index karte hai kyu nhi elongation index ??
Need to include a . Minimum no of pieces/ samples to take before test b . How it effect in durability in concrete c permissible limit Of combined index d . How to minimise combined index in coarse aggregate ??
Any reason for this??
not .8 its 1.8