Determinations for the flakiness index and flakiness and elongation of aggregate use a british standard classification system consisting of a thickness gauge for determining flakiness index and a metal length gauge for determining elongation index. This test method covers tests for flat particles, elongated particles, or flat and elongated particles in coarse aggregate. The elongation index is found by separating the elongation particles and expressing their mess as a percentage of the mass of sample tested. The scope of this test is to provide test methods for determining the elongation index of coarse aggregate. Nov 26, 2009 two years alone in the wilderness escape the city to build off grid log cabin duration. Aggregate elongation index tests open geotechnical. Is the combined flakiness and elongation index of aggregate. Bs1241 specifies a flakiness index not exceeding 30% irrespective of the aggregate size. This test is not applicable for sizes smaller than 6. Proportional calipers are efficient devices that quickly determine percentages of elongated and flat particles in coarse aggregate fractions.
Abrasion test is the measure of aggregate toughness and abrasion resistance such as crushing, degradation and disintegration. The particle shape of the aggregate is determined by. Pdf measurement of flat and elongation of coarse aggregate. Methods of test for aggregates for concrete, part i. This test is used to determine the particle shape of the aggregate and each particle.
Objective for determination of flakiness index of coarse aggregate, where the size of the coarse aggregate are larger than 6. Use this test method to determine the percentage of particles in a coarse aggregate material that have a thickness smallest dimension of less than onehalf of. The weight of retained aggregate on each sieve is measured and determined the percentage of retained. Flakiness and elongation index of coarse aggregate particle shape and surface texture influence the properties of freshly mixed concrete more than the properties of hardened concrete. For the determination of flakiness index 1 the aggregates are first sorted on test. Dec 06, 2016 flakiness and elongation of aggregates and concrete properties published on december 6, 2016 december 6, 2016 27 likes 9 comments. What is the significance of flakiness index and elongation index. Test procedure for determining flakiness index txdot designation. In order to study the basic mechanical properties and failure characteristics of all lightweight aggregate concrete with different volume of steel fiber 0%, 1%, 2%, shale ceramsite is used as. The elongation index is not applicable to sizes smaller than 6. Objective for determination of elongation index of coarse aggregate, where the size of the coarse aggregate are larger than 6.
Two years alone in the wilderness escape the city to build off grid log cabin duration. Both flakiness and elongation tests are not applicable to sizes smaller then 6. Shape tests of aggregate for highway material construction. Flakiness index test is not applicable for aggregates sizes smaller than 6. 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 coarse aggregate angularity caa test is a method of determining the angularity of coarse aggregate figure 1.
Pdf determination of the flakiness and the elongation index. A new computervision cellularphonebased methodology and scheme was developed to determine the shape properties flatness index, elongation index and roundness index of coarse aggregate particles. What various tests are done for the water, fine aggregates. The percentage by weight of flaky particles present in a given test sample. Flaky and elongated particles are considered undesirable for base coarse. Definition of flakiness index and elongation index civil. The concrete produced with natural uncrushed river aggregate. The aggregate retained on 63mm and passed through 6. The flakiness index is calculated by expressing the weight of flaky particles as a. The length gauge elongation index bs, is used to measure the elongation index of aggregates. Flakiness and elongation index of aggregate gilson co. Elongation index and flakiness index of coarse aggregate bs. Flakiness and elongation of aggregates and concrete properties published on december 6, 2016 december 6, 2016 27 likes 9 comments.
The test is carried on aggregate sizes between 63 mm and 6. The percentage by weight of the elongated particles present in a given test sample. For pavements either bituminous or nonbituminous, elongation index of coarse aggregate should not be more than 15%. Elongation index and flakiness index of coarse aggregate. The caa test estimates coarse aggregate angularity by visually inspecting a small sample of coarse. Each fraction is gauged in turn for thickness on the metal gauge. The dried aggregates sample is allowed to passing and retained on a set of sieve. As a conclusion, the sample that we tested are flaky and elongation, which is there are not suitable to use in parameter design. Dec 18, 2017 the elongation index is found by separating the elongation particles and expressing their mess as a percentage of the mass of sample tested. Aug 11, 2014 the flakiness index test fi is not applicable passing 6. Aggregate retained on the 75 mm and passing the 4,75 mm sieve is not included in the test. Take the aggregate sample which contains minimum 200 pieces of any fraction.
Retained on flakiness percentage of bakiness index. Exp 1 flakiness and elongation index civil engineers pk. The percentage of flaky and elongated particles that it contains. This british standard, a part of the bs 812 series, describes the method for determining the elongation index of coarse aggregate. Determination of elongation index linkedin slideshare.
The elongation index of an aggregate is the percentage by weight of particles whose greatest dimension length is greater than ninefifths 1. Elongation index is the percentage by weight of particles in it, whose largest dimension i. Flakiness and elongation test of aggregate as per is 2386 part 1, content aggregator duration. Flakiness index, elongation index and angularity number assessment of suitable shape or shape factors of. The presence of flaky or elongated particles in excess of 1015% of the weight of coarse aggregate is undesirable. The elongation index is the total weight of the material. Flakiness index and elongation index of coarse aggregates.
Aggregate quality for road construction will also influence the road performance. Determination of the flakiness and the elongation index for the given aggregate. In the british standard list this bs is described as current, obsolescent and, therefore, may. An adequate quantity of course aggregate is taken such that the minimum number of 200 pieces of any fraction can be tested. Following tests are conducted on coarse aggregates under shape tests. Elongation index the elongation index on an aggregate is the percentage by weight of particles whose greatest dimension length is greater than 1.
Elongation value is 0% because the aggregate is rounded so no any retain value. Aggregate is separated into seven sieve fractions from 636. Roughtextured, angular, and elongated particles require more water to produce workable concrete than smooth, rounded compact aggregate. What is the significance of flakiness index and elongation. In this text only flat and elongated particles in accordance with the procedure designated in method b will be covered. Tex224f, determining flakiness index overview effective date. The flakiness index of a coarse aggregate is determined by gauging screenedout fractions with the appropriate slots given in table i below. Determination of the flakiness and the elongation index for the given aggregate sample. Elongation index and flakiness index of coarse aggregate bs 812.
Doc flakiness index and elongation index of coarse. For more information read our blog characteristics of aggregates. Apr 07, 20 flakiness and elongation test of aggregate as per is 2386 part 1, content aggregator duration. Resistance to degradation of smallsize coarse aggregate. Aggregate angularity flakiness elongation index gilson co. Pdf determination of the flakiness and the elongation index for.
Maximum permitted elongated index is 35, 40 or 45% for aggregate sizes 2. This may be achieved either by drying at room temperature or by heating at a temperature of 100 to 110c. Coarse aggregate angularity is important to ensure adequate aggregate interlock and prevent excessive hma deformation under load figure 1. Flakiness index test is conducted by using a metal thickness gauge. Flakiness and elongation index of aggregate youtube. So, it is necessary to know the elongation index of given aggregate mix. The aggregate to be classified is separated into six sieve fractions from 6. This procedure discusses how to determine the number of flat or elongated particles in a coarse aggregate material. Determination of the flakiness and the elongation index. Flakiness index and elongation index test on coarse aggregates. Dec 12, 2017 flakiness and elongation index of coarse aggregate particle shape and surface texture influence the properties of freshly mixed concrete more than the properties of hardened concrete. The flakiness index test fi is not applicable passing 6. Elongation index test on coarse aggreagtes the constructor. Determination of the flakiness and elongation index for the given aggregate.
Report the elongation index in percentage rounded off to the nearest whole number. Sieve the sample through the is sieves as specified in the table. The elongation index test procedure contains following steps. May 08, 20 objective for determination of flakiness index of coarse aggregate, where the size of the coarse aggregate are larger than 6. Flaky and elongated particles may have adverse effects on concrete and bituminous mix. Passirg elongation gauge s eve size mm 50 4025 25 20 20 16 12. Mar 03, 2012 the value that we get from this test is 15. Definition the flakiness index of a coarse aggregate is the mass of particles in that aggregate. An aggregate is classified as being elongated if it has a length greatest dimension of more than 1.
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