Calculate the mean of the two results to the nearest whole number. Report the mean as the aggregate crushing value, unless the individual results differ by more than 0.07 times the mean value. In this case repeat the test on two further specimens, calculate the median of the four results to the nearest whole
AGGREGATE CRUSHING VALUE 1.Objective The aggregate crushing value gives a relative measure of the resistance of an aggregate to crushing under a gradually applied compressive load. With aggregate of aggregate crushing value 30 or higher, the result may be anomalous, and in such cases the ten percent fines value should be determined instead
Read MoreMay 17, 2019 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
Read MoreThe crushed aggregate sample which is finer than 2.36 mm is separated and expressed as a percentage of the original weight taken in the mould. The percentage of weight passed through the 2.36m IS sieve is known as Aggregate crushing value.. In situations, when the aggregate value 30 or higher the result may be a mistake and in such cases, the “ten percent fines value” should be determined
Read MoreAggregate crushing value test on coarse aggregates gives a relative measure of the resistance of an aggregate crushing under gradually applied compressive load. Coarse aggregate crushing value is the percentage by weight of the crushed material obtained when test aggregates are subjected to a specified load under standardized conditions
Read MoreApr 26, 2018 The aggregate crushing value is defined as the ratio of the weight of fines passing through specified IS (here 2.36mm sieve) to the total weight of sample expressed in percentage. W1= Weigh of the total aggregates (Wa-We) W2= Weigh of aggregates passing through 2.36mm IS sieve. Aggregate crushing value= ( W2 / W1 ) 100
Read MoreAGGREGATE CRUSHING VALUE This test helps to determine the aggregate crushing value of coarse aggregates as per IS: 2386 (Part IV) – 1963. The apparatus used is Cylindrical measure and plunger, Compression testing machine, IS Sieves of sizes – 12.5mm, 10mm and 2.36mm Procedure to determine Aggregate Crushing Value i) The aggregates passing through 12.5mm […]
Read MoreCalculation of Aggregate Crushing Value. The crushing value of aggregates is measured in the ratio between the crushed aggregates, obtained from the IS sieve 2.36mm and the weight of the dried aggregate sample. At least three samples should be tested from the same batch and average value to get accurate results
Read MoreAggregate is typically divided into two components:! Fine aggregate including sand – material passing a 3/8-inch screen sieve, essentially all passing a # 4 sieve (i.e., a 0.187-inch square opening). ! Coarse aggregate including gravel – generally considered being crushed stone or gravel, almost all of which is retained on a No. 4 sieve
Read MoreThe average crushing value in the different tests is the actual crushing value of aggregate. Important points to remember. It is recommended that the crushing value of aggregate should be less than 30%. If it is more than 30 % then 10% finer aggregate is suggested to use. The aggregate whose crushing value is less than 30% can be used for
Read More3.2.3 Crushing and sieving of the sample Proceed as in 3.1.3 but before sieving dry the material taken from the cylinder at 105-110EC for at least 16 h. 4 CALCULATIONS Calculate the dry or wet aggregate crushing value to the nearest 0,1 % as follows and report it
Read MoreThe aggregate crushing value provides a relative measure of the resistance of an aggregate to crushing under gradually applied crushing load. The aggregate crushing value test is a useful guide when dealing with aggregates of unknown performance, particularly when lower strength is suspected
Read MoreThe paper by Angove & Dunne (1997) reports a standard deviation in crushing work index tests across laboratories as 4.5. The laboratory CWi value of 27.4 (metric) is almost within 4.5 units of the 22.4 value I calculated, so what you are observing is probably the natural variation in the crushing test
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