Elongation index test procedure for aggregates civil4m. Elongation index of aggregate in % is calculated as follows. Quarter the aggregate sample to obtain a minimum of 200 particles passing the 78in. The elongation index is found by separating the elongation particles and expressing their mess. This british standard, a part of the bs 812 series, describes the method for determining the elongation index of coarse aggregate. 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. This test is not applicable to sizes smaller than 6. All aggregates are required to meet a minimum strength valve, as defined by the 10% value test. The elongation test is not applicable to sizes smaller than 6. The presence of flaky or elongated particles in excess of 1015% of the weight of coarse aggregate is undesirable. Maximum permitted elongated index is 35, 40 or 45% for aggregate sizes 2. Flakiness and elongation index shape test of aggregates. Determination of the flakiness and the elongation index for the given aggregate. The percentage of flaky and elongated particles that it contains.
In order to determine the effect of flakiness index on the bituminous mix, a number of aggregate test samples have to be prepared and upon each group of samples a certain percentage of flaky aggregate is applied which start from 0 to 5, 10, 15, 20, 25 %. Flakiness and elongation index of aggregate youtube. What do you mean by elongation index of an aggregate. Bitumen and aggregate test using in road construction. Elongation and flakiness test construction aggregate.
As such the flakiness and elongation test must be carried out to determine the suitability of the material. To assess suitability of aggregates for use in different types of road pavements introduction. Compacted weight fill the container in three equal layers, each layer being subjected to 25 strokes with the. Shape tests of aggregate for highway material construction. Elongation index test on coarse aggreagtes the constructor. The shape of aggregates is generally described in terms of its shape factors such as flakiness index, elongation index and angularity number.
Elongation value is 0% because the aggregate is rounded so no any retain value. When an aggregate particle has a thickness less than 0. Elongation index test experiment track gauge scribd. Retained on flakiness percentage of bakiness index. Flaky particles flaky particles are those whose least dimension is 0. What is the use of the elongation and flakiness index. What is the significance of flakiness index and elongation. Determination of elongation index linkedin slideshare. The dried aggregates sample is allowed to passing and retained on a set of sieve. Doc flakiness index and elongation index of coarse. Flakiness index test is not applicable for aggregates sizes smaller than 6. This test is not applicable for sizes smaller than 6.
How to determine flakiness index and elongation index test. Pdf determination of the flakiness and the elongation. The percentage by weight of the elongated particles present in a given test sample. Determine the empty weight m1 and the volume v of the cylinder at 270c. 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 test fi is not applicable passing 6.
The test is carried on aggregate sizes between 63 mm and 6. Elongation index and flakiness index of coarse aggregate. The length gauge elongation index bs, is used to measure the elongation index of aggregates. The particle shape of aggregate is determined by the percentages of flaky and elongated particles contained in it. Summary of test individual aggregates of specific sieve sizes are tested for ratios of width to thickness, length to width, or length to thickness. Aggregate testing from sigma test centre helps you ensure the quality of your concrete and complies with quality control standards and compulsory regulations. Elongation index and flakiness index of coarse aggregate bs 812. The sample of aggregates to be tested is sieved through page 6. 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.
It is intended that bs812 test methods should be called up by other british standards as the basis of compliance. Pdf determination of the flakiness and the elongation index for. Take representative sample of aggregate as required for the test according to maximum size of aggregate and the container required from table. In the british standard list this bs is described as current, obsolescent and, therefore, may. Just click on the names of the tests above to know the entire procedure of how we perform these tests. Elongation index is the % by weight of particles whose greater dimension is greater than 45 of the mean dimension elongation index wt of aggregate retained on specified gauge total wt of aggregate taken.
The equipment used in the flakiness index are also used in the elongation index test except a metal length gauge instead of a thickness gauge shown in figure. Aggregate and bitumen testing construction aggregate. While elongation index test is used to determine the quantity of aggregate particles that are elongated instead of cubicle in shape. Flakiness and elongation index shape test of aggregates as per is. Elongation index is the percentage by weight of particles in it, whose largest dimension i. The aggregate to be classified is separated into seven sieve fractions from 6. Transportation engineering experiments, flakiness index, elongation index. Both flakiness and elongation tests are not applicable to sizes smaller then 6.
Elongation index the elongation index of an aggregate is the percentage by weight of particles whose greatest dimension length is greater than one and four fifth times 1. Theory elongation index aggregate particles are classified as elongation when they have a length greatest dimension of more than 1. Flakiness index is the percentage by weight of particles in it, whose least dimension i. Where, w 1 weight of particles retained in length gauge grams. Apparatus the apparatus consists of the length gauge, sieves of the sizes specified in table 15. For this test aggregates passing 63 mm and retaining at 6. Is the combined flakiness and elongation index of aggregate is the numerical sum of separate elongation index and flakiness index.
What do you mean by flakiness index of an aggregate. The test is performed on a sample of coarse aggregate reduced from a representative field sample. The elongation index of an aggregate sample is found by separating the elongated particles and expressing their mass as a percentage of the mass of the sample tested. The particle shape of the aggregate is determined by. The elongation index of an aggregate is the percentage by weight of particles whose greatest dimension length is greater than 1 and 45th times 1. The total amount retained by the length gauge shall be weighed to an accuracy of at least 0.
The scope of this test is to provide test methods for determining the elongation index of coarse aggregate. Objective for determination of elongation index of coarse aggregate, where the size of the coarse aggregate are larger than 6. Flakiness index and elongation index test on coarse aggregates. Methods of test for aggregates for concrete, part i.
Flakiness index and elongation index of coarse aggregates. An aggregate is classified as being elongated if it has a length greatest dimension of more than 1. Bs1241 specifies a flakiness index not exceeding 30% irrespective of the aggregate size. How the elongation index of the sample helps in deciding the design of a highway. Definition of flakiness index and elongation index civil.
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. Or flat and elongated particles in coarse aggregate, american society for. The test is not applicable to material passing a 6. What is the procedure for elongation index of coarse. The particle shape of aggregates is determined by the percentages of flaky and elongated particle. The aggregate to be classified is separated into six sieve fractions from 6. The elongation index of an aggregate is the percentage by weight of particles whose greatest dimension length is greater than ninefifths 1.
Aggregates which are flaky and elongated are detrimental to the higher. Flakiness and elongation flakiness index sieve set uta0410. In case of gravel it is determined by its angularity number. Exp 1 flakiness and elongation index civil engineers pk. Download as docx, pdf, txt or read online from scribd. So, it is necessary to know the elongation index of given aggregate mix. The percentage by weight of flaky particles present in a given test sample. To determine the flakiness index and, to determine the elongation index of given aggregates sample. The test is not applicable to materials passing the 6. Determination of the flakiness and the elongation index for the given aggregate sample. Aggregate particles are classified as elongated when they have a length greatest dimension of more than 1. 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. The sample is sieved to separate each size larger than the 38 in.
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