Member shri r naarajan director civ engg shri

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Unformatted text preview: amp;to Member ) SHRI R. NA~ARAJAN, Director ( Civ Engg ) SHRI Senelary SHRI Y. R. TANEJA Deputy Director ( Civ Engg ), BIS Concrete Subcommittee, BDC 2:2 Convener SHRI S. B. Josa~ S. B. Joshi & Co Ltd, Bombay Membrrs DB S. M. K. CHETTY Central Building Roorkee Research Institute (CSIR), SHRI C. A. TANEJA ( Alternate) Soar B. K. CHOKSI In personal capacity ( ‘ Skrikunj ‘, flea? Parl;ash Housing Society , Athwa Lines, Swat ) The Concrete Association of India. Bombay SBRI 1. DATT SHRI C. L. N. IYEN~AR ( Alternate ) DEPUTY DIRECTOR, STANDARDS Research, Designs & Standards Organization ( Ministry of Railways j (B&S) ASSISTANT DIRECTOR, STANDARDS, M/C ( Altemu~e) Engineering Research Laboratories, Hyderabad DIRECTOR DIRECTOR ( CSM ) Central Water & Power Commission, New Delhi DIRECTOR ( DAMS III ) ( Alfemate ) DIBECT~R-IN-CHARGE Geological Survey of India, Lucknow ( Continued on page 2 19) IS : 383 - 1970 I Indian Standard SPECIFICATION FOR COARSE AND FINE AGGREGATES FROM NATURAL SOURCES FOR CONCRETE ( Second Revision ) 0. FOREWORD 0.1 This Indian Standard (Second Revision) was adopted by the Indian Standards Institution on 25 September 1970, after the draft finalized by the Cement and Concrete Sectional Committee had been approved by the Civil Engineering Division Council. 0.2 This standard was first published in 1952 1963. The present revision of the standard porate the modification necessary in the light use and also to bring it in line with the latest 0.2.1 The requirements included and it is proposed is printed. and subsequently revised in has been taken up to incorof experience gained in its thinking on the subject. for aggregates for mass concrete have been to withdraw IS: 515-1959*when this standard 0.3 The limiting values for the permissible deleterious materials in the aggregates, aggregate abrasion value and soundness test for aggregates have been revised, Recommendations have been included for the size of aggregates for mass concrete. The four grading zones for fine aggregates as specified in the earlier version of the standard have not been changed. These four grading zones become progressively finer from Grading Zone I The fine aggregates within each of to Grading Zone IV (see Table 4). these grading zones are suitable for making concrete, but to make concrete of high strength and durability, the mix proportions should be c!iosen according to the grading characteristics of the fine aggregates used; the ratio of fine to coarse aggregate being reduced as the fine aggregate becomes finer from Grading Zones I to IV. In particular, the correct design of the mix becomes increasingly important as the grading of the fine aggregate approaches the coarse outer limit.of Grading Zone I or the fine outer limit of Grading Zone IV, and the suitability of a given fine aggregate grading may, in some circumstances, depend on the grading and shape of the coarse aggregate. It is sometimes found that a fine aggregate which lies in one grading z...
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