The test is not applicable to material passing a 6. The value of the flakiness index is calculated from the expression. What is the significance of flakiness index and elongation. The flakiness index of aggregate is the percentage of the mass of the aggregates whose least dimension is less than 0. Thickness gauge flakiness index bs flakiness index. The flakiness index of course aggregate is defined in percentage by weight of aggregate particles and least dimension thickness of those particles should not be less than 0.
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. The test report shall affirm that the flakiness index test was performed according to the stated method and whether a sampling certificate was issued. The method makes reference to a particle size distribution procedure which is required for determination of flakiness index. Methods of test for aggregates for concrete, part i. Flakiness and elongation test of aggregate as per is 2386 part 1, content aggregator duration. This test is carried out to determine the flakiness index of aggregates. It is expressed as the percentage by weight of particles in a sample of more than 200 whose smallest dimension is less than 0. The percentage by weight of flaky particles present in a given test sample. Flakiness and elongation index of aggregate youtube.
The total amount passing the gauge shall be weighed to an accuracy of at least 0. The flakiness test is applicable to aggregates of size larger than 6. Flakiness index is the percentage by weight of particles in it, whose least dimension i. Procedure follow these steps to determine the flakiness index. This method describes the procedure for determining the flakiness index of. Perform a wash sieve analysis as directed in test method att26, nesting the. Flakiness sieves, aggregates testing equipment, controls. The presence of flaky or elongated particles in excess of 1015% of the weight of coarse aggregate is undesirable. The is is using an obsolete british standard procedure bs 812. The flakiness index of an aggregate sample is found by separating the flaky particles and expressing their mass as a percentage of the mass of the sample tested.
This test method covers tests for flat particles, elongated particles, or flat and elongated particles in coarse aggregate. Test procedure 2 transportation engineereing 2015civ for the. Astm d4791 19 standard test method for flat particles. Ariz 233d december 4, 2015 8 pages flakiness index of coarse aggregate an arizona method 1. Aggregate quality for road construction will also influence the road performance. In this text only flat and elongated particles in accordance with the procedure designated in method b will be covered. Shape tests on coarse aggregates such as flakiness index and elongation index. The method applies to aggregates having a nominal size not greater than 63. If available the sampling certificate should be provided.
This test is not applicable for sizes smaller than 6. Flakiness index british standard this part of this european standard specifies the procedure for the determination of the flakiness index of aggregate and applies to aggregates of natural or artificial origin, including lightweight aggregates. Pdf determination of the flakiness and the elongation index for. Calculate the flakiness index to the nearest 0,1 as follows.
Determining flakiness index step action 1 obtain a representative sample of processed aggregates according to test method tex221f, sampling aggregate for bituminous mixtures, surface treatments, and limestone rock asphalt. The test apparatus consists of a standard thickness gauge 6. Chapter 7 standard test procedures tests for aggregates and bricks may 2001 page 7. Objective for determination of elongation index of coarse aggregate, where the size of the coarse aggregate are larger than 6. Definition of flakiness index and elongation index civil. The elongation index is found by separating the elongation particles and expressing their mess as a percentage of the mass of sample tested.
Elongation index is the percentage by weight of particles in it, whose largest dimension i. Mithun is right, it is the percentage passing on each gauges were calculated and reported as flakiness index. Flakiness index and elongation index test on coarse aggregates. Exp 1 flakiness and elongation index civil engineers pk.
The particle shape of aggregates is determined by the percentages of flaky and. Method a is a reflection of the original procedure as developed prior to superpave and is intended for all nonsuperpave applications. This standard sets out a method for determining the flakiness index of an aggregate. The test is carried on aggregate sizes between 63 mm and 6. The percentage of flaky and elongated particles that it contains. Elongation index and flakiness index of coarse aggregate bs 812. Flakiness index sieve sets bs flakiness index utest. Elongation index and flakiness index of coarse aggregate. Thickness gauge is used to determine if the aggregate particles are to be considered as flaky, i. It is mentioned in the test procedure bismorth that while doing combined flakiness and elongation test, the flaky aggregates should be separated initially from the test sample, and the rest is. Uta0410 flakiness index sieve set consists of 7 sieves. Determination of the flakiness and the elongation index for the given aggregate.
Flaky index it is the percentage by weight of flaky particles in a sample. Length gauge elongation index has six labeled openings between metal pins for measuring length of particles from each of the six sieve cuts below 50mm, for elongation index determinations. We have a new team dedicated to providing accurate and timely information about test flakiness to help developers and build monitors so that they know whether. Flakiness index test is not applicable for aggregates sizes smaller than 6. Flakiness index 100 x m 3 m 2 express the flakiness index to the nearest whole.
Retained on flakiness percentage of bakiness index. The elongation index of an aggregate is the percentage by weight of particles whose greatest dimension length is greater than ninefifths 1. Flakiness index of aggregate materials testing manual part 7, transport and main roads, november 2018 2 of 4 5. Is sieves of the following mesh sizes 63mm, 50mm, 40mm, 31.
Elongation value is 0% because the aggregate is rounded so no any retain value. The particle shape of the aggregate is determined by. Sieve the sample through the is sieves as specified in the table. Flakiness index and elongation index of coarse aggregates. The flakiness index of a coarse aggregate is the mass of particles in that aggregate, expressed. Two procedures, method a and method b, are presented in this standard. The flakiness index test fi is not applicable passing 6. The dried aggregates sample is allowed to passing and retained on a set of sieve. The flakiness index test determines the percentage of flat particles in a seal coat aggregate. This test is for determining the flakiness index of aggregates used in asphalt surface treatments. Flat and elongated particles of coarse aggregates have a tendency to fracture more easily than. Flakiness index total mass of aggregate pass slots mass of test sample x 100 where. Test procedure for determining flakiness index txdot designation.
401 161 233 1351 476 444 186 535 60 1432 1508 1046 1300 524 827 1381 525 1250 146 443 726 1239 1461 782 1365 1353 89 539 1019 152 250 86 1202 948 988 1085