Procedure of Aggregate Impact Test The test sample consists of aggregates sized 10 0 mm 12 5 mm Aggregates may be dried by heating at C for a period of 4 hours and cooled i Sieve the material through 12 5 mm and 10 0mm IS sieves The aggregates passing through 12 5mm sieve and retained on 10 0mm sieve comprises the test material
AIV test is conducted to determine the Aggregate Impact Value of Coarse aggregate The aggregate impact value gives a relative measure of the resistance of an aggregate to sudden shock or impact which in some aggregates differs from Its resistance to a slow compression load The Indian Standard CODE IS 2386 Part IV 1963 is used for
The impact test on aggregate is carried out to know the response of aggregates to different kinds of loads that the aggregates will be subjected to during their service life The need for impact value test is used to measure the toughness of aggregates which is nothing but the ability of aggregates
Los Angeles L A Abrasion Test Figure 1 is a common test method used to indicate aggregate toughness and abrasion characteristics Aggregate abrasion characteristics are important because the constituent aggregate in HMA Hot Mix Asphalt samples should resist crushing degradation and disintegration in order to produce a high quality HMA
For the majority of aggregates the impact value and the crushing value are similar but brittle materials such as flints yield impact values which are about 5 units higher than their crushing values The impact test is widely used as an alternative to the crushing test
The aggregates crushing value test should be performed as per IS code 2386 Part IV First fill the sample aggregate with one third of the cylindrical measure in three layers Each layer should be tamped 25times freely After filling the sample aggregate weigh and record it as W1 Now fill the aggregate in the mould along with the plunger on top
And hence the finally aggregate impact value is 6 97 Significance of impact test The procedure of determining aggregate impact value is according to IS 2386 More will the impact value more will be the strength of aggregate The elongated and flaky aggregate has low strength as it has a higher surface area and gets more stress on it
The percentage mass of fines passing a 2 80mm BS test sieve formed in the test is known as the aggregate impact value AIV higher values are given by weaker materials For the majority of aggregates the impact value and the crushing value are similar but brittle materials such as flints yield impact values which are about 5 units higher than
2 days ago Aggregate Impact Tester With Blow Counter Determination of Aggregate Impact ValueImpact Test on Aggregates is done to carry out to Determine the impact value of the road aggregates Assess their suitability in road construction on the basis of impact value A testing machine
Standards BS 812 112 The Aggregate Impact Value Testing Apparatus meets with BS 812 it is robustly designed to determine the Aggregate Impact Value AIV of aggregates which provides a relative measure of the resistance of an aggregate to sudden shock or impact
2 Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard ASTM Standards C125 Terminology Relating to Concrete and Concrete Aggregates C131/C131M Test Method for Resistance to Degradation of Small Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine
C125 Terminology Relating to Concrete and Concrete Aggregates C131/C131M Test Method for Resistance to Degradation of Small Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine C136/C136M Test Method for Sieve Analysis of Fine and Coarse Aggregates C294 Descriptive Nomenclature for Constituents of Concrete Aggregates
Impact test on aggregate is determines the ability of an aggregate to withstand sudden loads Aggregates are the significant factor that contributes adequate strength to concrete Therefore it is important to obtain the right quality aggregate for construction Aggregates are often subjected to impact due to the movement of vehicles on road
Crushed ravel or stone which is obtained by crushing of hard stone or gravel Uncrushed stone or gravel resulting from natural disintegration of rock Partially crushed stone or gravel which is obtained by blending of above two types The graded coarse aggregate is defined by its nominal size i e 40 mm 20 mm 16 mm 12 5 mm etc
The advantages of aggregates impact value test are that the apparatus and procedure of the test are simple With this test we can obtain the resistance and impact of aggregates stones even in field condition The test can be done in a short period whether it is at construction site
The impact machine shall rest without wedging or packing upon the level plate block or floor so that it is rigid and the hammer guide columns are vertical The cup shall be fixed firmly in position on the base of the machine and the whole of the test sample placed in it and compacted by a single tamping of 25 strokes of the tamping rod
Impact Test For determining the toughness of stone it is subjected to impact test in a Page Impact Test Machine as followed A cylinder of diameter 25mm and height 25mm is taken out from the sample of stones It is then placed on cast iron anvil of machine
IS 2386 Part IV 1963 2 2 ApparatusThe apparatus for the standard test shall consist of following a A 15 cm diameter open ended steel cylinder with plunger and base plate of the general form and dimensions shown in Fig 1
Impact test The aggregate impact test is carried out to evaluate the resistance to impact of aggregates Aggregates passing 12 5 mm sieve and retained on 10 mm sieve is filled in a cylindrical steel cup of internal dia 10 2 mm and depth 5 cm which is attached to a metal base of impact testing machine
Procedure of Aggregate Impact value test The test sample normally aggregates sized 10 0 mm to 12 5 mm the aggregates should be dried by heating at 0C for a period of 4 hours and cooled Sieve the material through 12 5mm and 10 0 mm IS sieves The aggregates passing through 12 5 mm sieve comprises the test
The specific gravity test helps in the identification of stone Water absorption gives an idea of the strength of aggregate Aggregates having more water absorption are more porous in nature and are generally considered unsuitable unless they are found to be acceptable based on strength impact
The aim of this study was to determine the impact of mechanical properties of aggregates on ordinary and high performance concretes with these aggregates Research included aggregate crushing resistance and mechanical properties of 24 concretes with basalts granites granodiorite dolomite quartzite gravels from 13 Polish and Ukrainian mines
Aggregate Impact Value Testing machine The test equipment and the test procedure are quite simple and it determines the resistance to impact of stone aggregates simulating field condition This test can be performed even at construction site or at stone
The Los Angeles L A Abrasion Test is widely used as an indicator of the relative quality of aggregates It measures the degradation of standard gradings of aggregates when subjected to abrasion and impact in a rotating steel drum with an abrasive charge of steel balls The drum is fitted with an internal shelf that lifts and drops the charge
Procedure of Aggregate Impact Test The test sample consists of aggregates sized 10 0 mm 12 5 mm Aggregates may be dried by heating at C for a period of 4 hours and cooled i Sieve the material through 12 5 mm and 10 0mm IS sieves The aggregates passing through 12 5mm sieve and retained on 10 0mm sieve comprises the test material
aggregate impact test The aggregate impact test determines the ability of an aggregate to withstand sudden loads During sudden loads the aggregates may break into pieces Hence to analyse to provide the adequate quality we perform this aggregate test
C125 Terminology Relating to Concrete and Concrete Aggregates C131/C131M Test Method for Resistance to Degradation of Small Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine C136/C136M Test Method for Sieve Analysis of Fine and Coarse Aggregates C294 Descriptive Nomenclature for Constituents of Concrete Aggregates
Types of Test Carried Out On The Coarse Aggregates 1 Crushing Value Test of Aggregate IS 2386 Part IV 1963 The crushing value is the relative measure of the resistance which can be offered by the aggregate to the crushing under the action of the gradually applied load 2 Impact Value Test of Aggregate IS 2386 Part IV 1963
The apparatus used for determining aggregate impact value of coarse aggregates is Impact testing machine conforming to IS 2386 Part IV 1963 IS Sieves of sizes12 5mm 10mm and 2 36mm A cylindrical metal measure of 75mm dia and 50mm depth A tamping rod of 10mm circular cross section and 230mm length rounded at one end and Oven
The strength of coarse aggregates is assessed by aggregates impact test The aggregate impact value provides a relative measure of resistance to crushing under a gradually applied compressive load To achieve a high quality of pavement lower aggregate impact value should be preferred Toughness is the property of a material to resist impact
Impact Test Fig 3 Impact Test Setup The aggregate impact test is carried out to evaluate the resistance to impact of aggregates Aggregates passing 12 5 mm sieve and retained on 10 mm sieve is filled in a cylindrical steel cup of internal dia 10 2 mm and depth 5 cm which is attached to a metal base of impact testing machine
Impact Test of Stone The resistance of stones to impact is found by conducting tests in impacting the testing machine Below Figure It consists of a frame with guides where a metal hammer weighing 13 5 to 15 kg can freely fall from a height of 380 mm
The aggregates crushing value test should be performed as per IS code 2386 Part IV First fill the sample aggregate with one third of the cylindrical measure in three layers Each layer should be tamped 25times freely After filling the sample aggregate weigh and record it as W1 Now fill the aggregate in the mould along with the plunger on top
Aggregate impact value test gives an indication of aggregate s toughness property i e property of a material to resist impact Aggregates to be used for wearing course the impact value shouldn t exceed 30 per cent For bituminous macadam the maximum permissible value is 35 per cent For Water bound macadam base courses the maximum permissible value defined by IRC is 40 per cent
Concept and significance of the Aggregate crushing value test The aggregate crushing value test ` gives a relative measure of the resistance of an aggregate to crushing under a gradually applied compressive load Aggregate crushing value is defined as the percentage by weight of the crushed or finer material obtained when the test aggregates are subjected to a specified load under
The aggregate impact value test is an important test of aggregates It is done to obtain the resistance and impact of aggregates stones In this test a machine is used which is called impact testing machine What are the Importance of Aggregate Impact Value Test
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