Tl4nitiuns covcrcd under 21 to 23 definitions shall

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Unformatted text preview: s covcrcd under 2.1 to 2.3. definitions shall apply. cnvcring glossary of terms rclatir)S co aggreThe standard when publisbcd will include Aggregate most of which passes 4.75-mm 2.1 Fine Aggregatcand contains only so much coarser material as permitted in 4.3. IS Sieve 2.1.1 JVuttrral Sand - Fine aggregate resulting from the natural disintegration of rock and which has been deposited by streams or glacial agencies. produced by crushing hard 2.1.2 Crushed Stone Sand - Fine aggregate stone. 2.1.3 Crushed Grace1 Sand - line aggregate produced by crushing natural gravel. . 2.2 Coarse Aggregate -- Aggregate most of which is retained on 4*75-mm IS Sieve and containing only so much finer material as is permitted for the various types described in this standard. NOTE -Coarse aggregate a) uncrushcd rock, may gravel b) crushed gravel stone, and or stone c) partially crushed uf (a) and (b). All-in-Aggregate aggregate. 2.3 3. QUALITY - be described or stone gravel l\Iaterial which when as: results it results or stone when composed from from natural crushing it is a product disintegration of gravel of the of fine aggregate of or hard blending and coarse- OF AGGREGATES 3.1 General - r1ggrcgntc shall consist of naturally occurring ( crushed or uncrushed ) stones, gravel and sand or combination thereof. They shall be harcl, strong, ~CIISC, dural)lc, clear and free from veins and adherent coating; and tiee from irrjurious amounts of disintegrated pi.eces, alkali, vegetable matter and otlicr deleterious substances. As far as possible, . flaky, scoriaceous and clongatccl pieces should be avoided. 5 : :I.. TS : 383 - 1970 shall not contain any harmful 3.2 Deleterious Materials -Aggregates :li;lt~.l~iai, such as pyrites, coal, lignite, mica, shale or similar laminated material, clay, alkali, soft fragments, sea shells and organic impurities in such quantity as to affect the strength or durability of the concrete. Aggrqates to. be used for reinforced concrete shall not contain any Aggregates which are mater:aI liable to attack the steel reinforcement. chemically reactive with alkalies of cement are harmful as cracking of concrete may take place. SITE - Aggregates petrographically similar to known reactive types or aggrecates wllich, on the basis of service history or laboratory exprriments, are suspected to haxve reactive tendency sholdd be avoided or used only with cements of low alkalies [not morr than 0.6 percent as sodillm oxide ( iKa,O )]. after detailed lnboracrwy stllclies. uw of pozzolanic cement and certain pozzolanic admixtures may be helpful in controlling alkali aggregate reaction. 3.2.1 Litr~its d Deleterious Materials-The maximum quantity of deleterious materials shall not rxce,cd the limits specified in Table 1 when tested in accordance with IS : 2386-1963. However, the erqineer-in-charge at his discretion, may relax some of the limits as a result of-some fLtrrher tests and evidence of satisfactory performance of the aggregates. 3.3 Aggregate Crushing Value-The aggrc...
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