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Unformatted text preview: gnte crushing value, when determined in accordance with IS: 2386 (Par! IV)-1963 shall not exceed 45 pcrcwt for aggregate used for concrete other than for wt lring surfaces, and 30 percent for concrete for wearing surfaces, such as runways, roads and pavements. 3.4 Aggregates Impact ValueAs an alternative to 3.3 the aggregate impact value may be determined in accordance with the method specified iu IS : 2386 i Part IV )-1963. The aggregate impact value shall not exceed 45 percent by weight for aggregates used for concrete other than for wearing surfaces and 30 percent by weight for concrete for wearing surfaces, such as runways, roads and pavements. 3.5 Aggregate Abrasion ValueUnless otherwise agreed to between the purchaser and the supplier, the abrasion value of aggregates, when tested in accordance with the method specified in IS:2386 (Part IV)1963 using Los Angeles machine, shall not exceed the following values: a) For aggregates to be used in concrete for wearing surfaces 30 percent t,) For aggregates other concrete 50 perrent to be used in 3.6 Soundness of AggregateFor concrete liable to be exposed the action of frost, coarse and fine aggregates shall pass a sodium or magnesium sulphate ;rccelerated soundness test specified in IS: 2386 (Part V)-1963, the limits being set by agreement between the purchaser and the supplier, IS : 383 - 1970 except that aggregates failing in the accelerated soundness test may be used if they pass a specified freezing and thawing test satisfactory to the user. Nova - As a general guide, it may be taken that the average cycles shall not exceed the following: 10 percent ( Na,SO, a) For fine aggregate when tested ), and 15 percent when slllphate ( MgSO, 1) For coarse aggrega:e 4. SlZE AND GRADING percent when sulphate ( hlgS0, with sodium sulphate tested with magnesium ) 1’2 percent when tested ( Sa s50, ), and 18 loss of weight after 5 with sodium sulphate tested with magnesium ) OF AGGREGATES 4.1 Single-Sized Coarse Aggregates -Coarse aggregates shall be in the nominal sizes given in Table 2. For any one of the nominal sizes, the proportion of other sizes, as determined by the method described in IS :238G (Part I)-1963 shall also be in accordance with Table 2. supplied 4.1.1 Coarse A,:gwgafe concrete for Mass Concrete- works shall be in the sizes specified 4.2 Graded the nominal Aggregates-Graded sizes given in Table Coarse aggregate in Table 3. coarse aggregates for mass may be supplied in 2. 4.3 Fine Aggregates -The grading of fine aggregates, when determined as described in IS: 2386 (Part I)-1963 shall bc within the limits given in Table 4 and shall be described as fine aggregates, Grading Zones I, II, Where* the grading falls outside the limits of any particular III and IV: grading zone of sieves other than 600-micron IS Sieve by a total amount not exceeding 5 percent, it shall be regarded as falling within that grading zone. This tolerance shall not be applied to percentage passing the 600-micron IS Sieve...
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This document was uploaded on 10/01/2013.

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