Objective for determination of elongation index of coarse aggregate, where the size of the coarse aggregate are larger than 6. Flakiness and elongation index of aggregate with calculation duration. Determination of the flakiness and the elongation index for the given aggregate sample. Particle shape and surface texture influence the properties of freshly mixed concrete. Aggregate particles are classified as flaky when they have a thickness of less than 0. Flakiness and elongation index of aggregate youtube. This standard specifies a method for determining the flakiness index of coarse aggregate that passes a sieve of aperture size 75 mm and that is retained on a sieve of aperture size 4 750 om. Definition the flakiness index of a coarse aggregate is the mass of particles in that aggregate, expressed as a percentage of the total mass of that aggregate.
Elongation index and flakiness index of coarse aggregate. 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 length gauge elongation index bs, is used to measure the elongation index of aggregates. The flakiness index test fi is not applicable passing 6. This british standard, a part of the bs 812 series, describes the method for determining the elongation index of coarse aggregate. In this experiment, flakiness index was used as independent variables and other properties such as gradation are kept constant as far as their properties met the specification required for the asphalt mixture. Finally, you can have numerical sum of flakiness index and elongation index to get combined f. Mean size of aggregates is defined as the mean of two seive sizes, between which the particle is retained.
Adjustment of flaky aggregates flakiness index test is applicable on those aggregate sizes bigger than 6. Flat particles, elongated particles, or flat and elongated particles in coarse aggregate astm d 4791 glossary flat and elongated particles of aggregate those particles having a ratio of length to thickness greater than a specified value. Flakiness index and elongation index test on coarse aggregates. Aggregate particles are classified as elongated when they have a length greatest dimension of more than 1. Flakiness and elongation flakiness index sieve set uta0410. The elongation index of aggregates is the percentage by weight of particles whose.
This method is based on the classification of aggregate particles as flaky when they have a thickness smallest dimension of less than 0. 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 procedure discusses how to determine the number of flat or elongated particles in a coarse aggregate material. Combined effect of flaky and elongated aggregates on. Definition the flakiness index of aggregates is the percentage by weight of particles whose least dimension thickness is less than 0. For base course and construction of bituminous and cement concrete types, the presence of flaky and elongated particles are considered undesirable as these cause inherent. The scope of this test is to provide test methods for determining the elongation index of coarse aggregate.
Particle shape and surface texture influence the properties of freshly mixed concrete more than the. Flakiness sieves, aggregates testing equipment, controls. Chapter 2 bituminous tex224f, determining flakiness index manual of testing procedures 1 899 1004 tex224f, determining flakiness index overview effective date. Proportional calipers are efficient devices that quickly determine percentages of elongated and flat particles in coarse aggregate fractions. Flakiness and elongation test construction aggregate road. Flakiness and elongation test of aggregate as per is 2386. Exp 1 flakiness and elongation index civil engineers pk. Determination of the flakiness and the elongation index for the given aggregate. The aggregate retained on 63mm and passed through 6. Aggregate quality for road construction will also influence the road performance. Definition of flakiness index and elongation index civil. The aggregate to be classified is separated into seven sieve fractions from 6. Bitumen and aggregate test using in road construction.
The aggregate to be classified is separated into six sieve fractions from 6. When an aggregate particle has a thickness less than 0. To evaluete the thickness and the elongation index of the aggregates particles, thickness gauge code 47d0540 and length gauge code 47d0541 can be used. Flakiness and elongation test of aggregate as per is 2386 part 1, content aggregator duration.
Flakiness index is the percentage by weight of particles in it, whose least dimension i. Flakiness and elongation index of aggregate gilson co. The amount of aggregate available should be sufficient to provide. The particle shape of aggregates is determined by the percentages of flaky and elongated particles contained in it.
Flakiness index and elongation index of coarse aggregates. Elongation index is the % by weight of particles whose greater dimension is greater than 45 of the mean dimension. In order to determine the effect of flakiness index on the bituminous mix, a number of aggregate. Not so much different between both of the two values. This process is carried out when the aggregate proportions such as coarse, fine and dust is identified.
Pdf determination of the flakiness and the elongation index for. Elongation index and flakiness index of coarse aggregate bs 812. Flakiness and elongation test of aggregate as per is 2386 part 1, content aggregator. Aggregate is separated into seven sieve fractions from 63. Transportation engineering experiments civil engineers pk. 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 and elongation rocks are not suitable for road construction because this type of rocks will make the road surface not balance and easy to damage. Conclusion based on the objective for this experiment is to identify the flakiness and elongation index of the given aggregrate samples, we indentified the flakiness and elongation is not influenced each other. Shape tests flakiness index elongation index angularity number tested particles grater than 6.
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. Theory of flakiness index and elongation index tests the particle shape of aggregates is determined by the percentages of flaky and elongated particles contained in it. The test is carried on aggregate sizes between 63 mm and 6. While elongation index test is used to determine the quantity of aggregate particles that are elongated instead of cubicle in shape. Shape tests on coarse aggregates such as flakiness index and elongation index, its importance in concrete. Take the aggregate sample which contains minimum 200 pieces of any fraction. Pdf determination of the flakiness and the elongation. The elongation index test procedure contains following steps. What are the difference between tender and contract documents. Aggregate retained on the 75 mm and passing the 4,75 mm sieve is not included in the test. Determination of materials finer than 75micron, determination of flakiness index, determination of elongation index, and determination of angularity number.
The dried aggregates sample is allowed to passing and retained on a set of sieve. Flakiness index test is not applicable for aggregates sizes smaller than 6. The percentage by weight of flaky particles present in a given test sample. B elongation index test 1 sample of aggregates were prepared. This work aims at establishing the same quantitatively. Combined effect of flaky and elongated aggregates on strength and workability of concrete has often been qualitatively expressed. What is the significance of flakiness index and elongation. Flakiness and elongation of aggregates and concrete properties published on december 6, 2016 december 6, 2016 27 likes 9 comments. Methods of test for aggregates for concrete, part i. Now, you need to find the amount of elongated particles to the aggregates which passed flakiness test.
Elongation value is 0% because the aggregate is rounded so no any retain value. Aggregate and bitumen testing construction aggregate. Similarly, the particle is considered as flaky if its thickness is less than 0. Flakiness, elongation and angularity number scribd.
Quarter the aggregate sample to obtain a minimum of 200 particles passing the 78in. Thickness the maximum dimension perpendicular to the length and width. Roughtextured, angular, and elongated particles require more water to produce workable concrete than smooth, rounded compact aggregate. Flakiness and elongation of aggregates and concrete properties. Aggregate and bitumen testing free download as powerpoint presentation. An aggregate is classified as being elongated if it has a.