Elongated and flaky stones are normally not very suitable for road works since the shape and the size make them difficult to compact. Theory of flakiness index and elongation index tests. The apparatus for the shape tests consists of the following. Elongation index and flakiness index of coarse aggregate bs 812 part. When the coarse aggregate does fracture, the gradation will likely change which may be detrimental to the mix. Flakiness and elongation test construction aggregate road. Elongation index is the percentage by weight of particles in it, whose largest dimension i. 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. Dec 06, 2016 flakiness and elongation of aggregates and concrete properties published on december 6, 2016 december 6, 2016 27 likes 9 comments. This work aims at establishing the same quantitatively. The flakiness of aggregate is determined by measuring the thickness of individual particles.
Apr 07, 20 this feature is not available right now. As such the flakiness and elongation test must be carried out to determine the suitability of the material. Flakiness and elongation index shape test of aggregates as per is. Flakiness index sieve set uta0410 when an aggregate particle has a thickness less than 0. Retained on flakiness percentage of bakiness index. Adjustment of flaky aggregates flakiness index test is applicable on those aggregate sizes bigger than 6. Is the combined flakiness and elongation index of aggregate. What is the significance of flakiness index and elongation. 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 elongation index of aggregates is the percentage by weight of particles whose greatest.
This test method covers tests for flat particles, elongated particles, or flat and elongated particles in coarse aggregate. Determination of flakiness index, determination of elongation index, and determination of angularity number. The test is not applicable to material passing a 6. In bituminous mixtures, flaky aggregates make for a harsh mix and may also crack and break up during compacting by rolling. A quantity of aggregate shall be taken sufficient to provide the minimum number of 200 pieces of. To evaluete the thickness and the elongation index of the aggregates particles, thickness gauge code 47d0540 and length gauge code 47d0541 can be used. The mass of all flaky particles as a percent of the whole sample is the flakiness index. For pavements either bituminous or nonbituminous, elongation index of coarse aggregate should not be more than 15%. Similarly, the particle is considered as flaky if its thickness is less than 0. Flakiness and elongation index of coarse aggregate. What is the use of flakiness index in concrete road work. To determination of flakiness index and elongation index of course aggregates. Aug 11, 2014 the flakiness index of aggregates is determined by the percentage of flaky particles contained in it.
This method is based on the classification of aggregate particles as flaky when they have a thickness smallest dimension of less than 0. Flat and elongated particles of coarse aggregates have a tendency to fracture more easily than other aggregate particles. Flakiness and elongation of aggregates and concrete properties published on december 6, 2016 december 6, 2016 27 likes 9 comments. The elongation index of an aggregate is the percentage by weight of particles whose greatest dimension length is. Determination of flakiness index of the coarse aggregate. How to determine flakiness index and elongation index test. The aggregate retained on 63mm and passed through 6. Exp 1 flakiness and elongation index civil engineers pk. As a conclusion, the sample that we tested are flaky and elongation, which is there are not suitable to use in parameter design. Combined effect of flaky and elongated aggregates on strength. The particle is considered as elongated if its length is more than 1. The flakiness index of aggregates is the percentage by weight of particles whose least dimension thickness is less than three fifths 0.
May 08, 20 objective for determination of flakiness index of coarse aggregate, where the size of the coarse aggregate are larger than 6. Flakiness and elongation of aggregates and concrete properties. Hm925 flakiness index gauge meets bs en 9333 specifications and features seven slots for rapid hand trying of particles from each of the seven sieve fractions from 2. For the love of physics walter lewin may 16, 2011 duration. Grid sieve set uta uta0420 the grid sieve set is used to determine the flakiness index of the aggregate. Aggregate angularity flakiness elongation index gilson co. All the sieves include an electrostatically painted frame. The elongation index test procedure contains following steps. Separation of elongated material each fraction shall be gauged individually for length on a metal length gauge of the pattern shown in fig. The percentage by weight of flaky particles present in a. Flakiness and elongation index of aggregate youtube. Flat and elongated particles of coarse aggregates have a tendency to fracture more easily than. Mar 12, 2015 i flakiness index is the percentage by weight of particles in it, whose least dimension i.
Uta0410 flakiness index sieve set consists of 7 sieves. Report the elongation index in percentage rounded off to the nearest whole number. Determination of elongation index linkedin slideshare. The flakiness index of the aggregate is the percentage by weight of particles in it, whose least dimension thickness is less than three fifth of their mean dimension.
Flakiness sieves, aggregates testing equipment, controls. When an aggregate particle has a thickness less than 0. Mean size of aggregates is defined as the mean of two seive sizes, between which the particle is retained. What is the significance of flakiness index and elongation index. The aggregate to be classified is separated into seven sieve fractions from 6. Pdf determination of the flakiness and the elongation.
Determination of the flakiness and the elongation index for the given aggregate sample. Mar 03, 2012 as such the flakiness and elongation test must be carried out to determine the suitability of the material. An aggregate is classified as being elongated if it has a. Hence we offer thickness gauge and length gauge to check flakiness and elongation index of the aggregate respectively. Flakiness index and elongation index of coarse aggregates. Pdf determination of the flakiness and the elongation index. Dec 24, 2018 recommended values of flakiness index. Flakiness and elongation index of aggregate gilson co. Flakiness index test is not applicable for aggregates sizes smaller than 6. Such particles make poor concrete, since they are hard to compact, and e. The flakiness index of aggregates is determined by the percentage of flaky particles contained in it. To determine the flakiness index of the coarse aggregate. 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. This test is not applicable to sizes smaller than 6.
The flakiness index is the total weight of the material. May 08, 20 objective for determination of elongation index of coarse aggregate, where the size of the coarse aggregate are larger than 6. Finally, you can have numerical sum of flakiness index and elongation index to get combined f. Now, you need to find the amount of elongated particles to the aggregates which passed flakiness test. The elongation index is found by separating the elongation particles and expressing their mess as a percentage of the mass of sample tested. 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. Dec 18, 2017 elongation index aggregate particles are classified as elongation when they have a length greatest dimension of more than 1.
Following tests are conducted on coarse aggregates under shape tests. The scope of this test is to provide test methods for determining the elongation index of coarse aggregate. Aggregates which are flaky andor elongated will often. The particle shape of aggregates is determined by the percentages of flaky and elongated particle. Lab equipments flakiness manufacturer from ahmedabad.
Objective for determination of flakiness index of coarse aggregate, where the size of the coarse aggregate are larger than 6. Determination of the flakiness and the elongation index for the given aggregate. In this text only flat and elongated particles in accordance with the procedure designated in method b will be covered. The percentage by weight of flaky particles present in a given test sample. The test is carried on aggregate sizes between 63 mm and 6. Definition of flakiness index and elongation index civil. To assess suitability of aggregates for use in different types of road pavements introduction. Definition the flakiness index of aggregates is the percentage by weight of particles whose least dimension thickness is less than 0. This process is carried out when the aggregate proportions such as coarse, fine and dust is identified. For base course, and construction of asphalt and cement concrete types the presence of flaky particles is considered undesirable as it may cause inherent weakness with possibilities of braking down under heavy loads. Thickness gauge flakiness index is a slotted stainless steel gauge for rapid hand trying of particles from the seven sieve fractions to determine the 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. To determine the flakiness index and, to determine the elongation index of given aggregates sample. Elongated and flaky stones are normally not very suitable for road works since the.
Combined effect of flaky and elongated aggregates on. Elongation index and flakiness index of coarse aggregate. This paper describes the importance of the particle shape of aggregates in road structures, and their determination, especially using the flakiness index test. Objective for determination of elongation index of coarse aggregate, where the size of the coarse aggregate are larger than 6. Quarter the aggregate sample to obtain a minimum of 200 particles passing the 78in. Combined effect of flaky and elongated aggregates on strength and workability of concrete has often been qualitatively expressed. Elongation index and flakiness index of coarse aggregate bs. Shape tests on coarse aggregates such as flakiness index and elongation index, its importance in concrete construction, methods of determination is discussed. Proportional calipers are efficient devices that quickly determine percentages of elongated and flat particles in coarse aggregate fractions. Flakiness index is the percentage by weight of particles in it, whose least dimension i. Take the aggregate sample which contains minimum 200 pieces of any fraction. Flakiness and elongation flakiness index sieve set uta0410.