IS 6461 (Part 1) — Concrete Aggregates · Concrete Glossary

Absorption Cl 3.1

The process by which a liquid is drawn into and tends to fill permeable pores in a porous solid body; also, the increase in weight of a porous solid body resulting from the penetration of a liquid into its permeable pores.

Note — In the case of concrete and concrete aggregates, unless otherwise stated, the liquid involved is water, the increase in weight is that which does not include water adhering to the outside surface, the increase in weight is expressed as a percentage of the dry weight of the body and the body is considered to be ‘dry’ when it has been treated by an appropriate process to remove uncombined water, such as drying to constant weight at a temperature between 100 °C and 110 °C.

Aggregate Cl 3.2

Granular material, generally inert, such as natural sand, manufactured sand, gravel, crushed gravel, crushed stone, and air -cooled iron blast furnace slag which when bound together into a conglomerated mass by a matrix forms concrete or mortar. Granular material such as sand gravel crushed stone or iron blast furnace slag use with cementing medium to form hydraulic cement concrete or mortar.

Aggregate, All Cl 3.3

in ― Material composed of a mixture of coarse aggregate and fine aggregate.

Ballast, Al l Cl 3.1

in ― Aggregate containing a substantial proportion of all sizes (including sand) below a stated maximum, as obtained from a pit, river-bed or seashore.

Crusher Cl 3.2

Run Stone ― Rock that has been broken in a mechanical crusher and has not been subjected to any subsequent screening process.

Aggregate, Coarse Cl 3.4

Aggregate most of which is retained on 4.75 mm IS sieve and containing only so much of finer material as is permitted by the specification. or Portion of an aggre gate retained on the 4.7 5 mm IS sieve.

Note — S 1 The definitions are alternatives to be applied under differing circumstances. 2 Coarse aggregate may be described as: a) Crushed gravel-coarse aggregate produced by crushing gravel (see 3.30); b) Crushed stone-coarse aggregate produced by crushing of hard stone (see 3.32); c) Uncrushed gravel-coarse aggregate resulting from natural disintegration of rock; that is without crushing. d) Partially crushed gravel or stone when it is a product of the blending of (a) and (b); and e) Manually broken stone, that is produced by breaking hard stone manually with hammers.

Aggregate, Dense Graded Cl 3.5

Aggregates graded to produce low void content and maximum weight when compacted.

Aggregate, Fine Cl 3.6

Aggregates most of which passes 4 .75 mm IS sieve and containing only so much coarser material as is permitted for various grading zones in the specification. Fine aggregate may be described as in 3. 6.1 to 3.6.3.

Natural Sand Cl 6.1

Fine aggregate resulting from the natural disintegration of rock and/or which has been deposited by streams or glacial agencies. 1 IS 6461 (Part 1) : 2024 To access Indian Standards click on the link below: https://www.services.bis.gov.in/php/BIS_2.0/bisconnect/knowyourstandards/Indian_standards/isdetails/

Crushed Stone Sand Cl 6.2

Fine aggregate produced by crushing hard stone.

Crushed Gravel Sand Cl 6.3

Fine aggregate produced by crushing natural gravel.

Aggregate, Gap Graded Cl 3.7

Aggregate having a particle size distribution where one or more sizes are missing.

Aggregate, Graded Cl 3.8

Aggregate comprising of a proportion of all sizes from a given nominal maximum to 4.25 mm. When thes e sizes are so proportioned as to give a definite grading, it is a well graded aggregate.

Aggregate, Heavy Weight Cl 3.9

Aggregate of high specific gravity, such as barite magnetite, limonite, ilemenite iron, or steel used to produce heavy concrete or high density concrete specially for shielding against nuclear radiation.

Aggregate, Light Weight Cl 3.10

Aggregate of low bulk specific gravity, such as expanded or sintered clay, slate, slag, fly ash, vermiculite, or pumice or natural pumice rock used to pr oduce light weight concrete.

Aggregate, Maximum Size of Cl 3.11

The largest size of aggregate particles present ill sufficient quantity to influence the physical properties of concrete, generally designated by the standard sieve nearest to the sieve size on which over 10 percent weight is retained.

Aggregate, Mineral Cl 3.13

Aggregates consisting essentially of inorganic nonmetallic rock materials, either natural or crushed and graded.

Aggregate, Reactive Cl 3.14

Aggregate containing substances capable of reacting chemically with the products of solution or hydration of the Portland cement in concrete or mortar under ordinary conditions of expo sure, resulting in some cases in harmful expansion, cracking, or staining.

Aggregate, Refractory Cl 3.15

Materials having refractory properties which when bound together into a conglomerate mass by a matrix, from a refractory body.

Alkali Reactivity (of Aggregate) Cl 3.15.1

Susceptibility of aggregate to alkali-aggregate reaction.

Aggregate, Single Sized Cl 3.16

Aggregate the bulk of which passes one sieve on the normal concrete series and is retained on the next smaller size. 3.17 b/bo ― Dry rodded bulk volume of coarse aggregate per unit volume of concrete; the ratio of the solid volume of coarse aggregate particles per unit volume of freshly mixed concrete to the solid volume of the coarse aggregate particles per unit volume of dry rodded coarse aggregate.

Ballast Cl 3.18

Stone or gravel mixture of irregular unscreened sizes which may also contain sma ller material and sand.

Blast Furnace Slag Cl 3.19

Non-metallic product consisting essentially of glass containing calcium and magnesium silicates and alumino silicates and other bases, which is developed simultaneously with iron in blast furnace or electric pig iron furnace.

Ball Cl 3.19.1

Slag ― Blast furnace slag which has been allowed to solidify in the ladle.

Bank Cl 3.19.2

Slag ― Blast furnace slag which has been poured in a molten state on a bank and allowed to solidify.

Pit Cl 3.19.3

Slag or Modified Pit -Slag ― Blast furnace slag which has been poured in a molten state into prepared pits, canals or large moulds and allowed to solidify therein.

Blast Furnace Slag, Air Cl 3.20

Cooled ― The material resulting from solidification of molten blast furnace slag und er atmospheric conditions. Subsequent cooling may be accelerated by application of water to the solidified surface.

Blast Furnace Slag, Expanded or Foamed Cl 3.21

The light weight cellular material obtained by controlled processing of molten blast furnace slag with water, or with water and other agents, such as steam or compressed air or both; and crushed and graded as required. It consists chiefly of alumino silicates of lime and magnesia in a glassy, partly crystalline or crystalline condition.

Blast Furnace Slag, Granulated Cl 3.22

Granulated slag is obtained by further processing the molten slag by rapidly chilling or quenching it with water or steam and air. Granulated blast furnace is used for the manufacture of hydraulic cement.

Bloated Cl 3.23

Swollen, as certain light weight aggregates as a result of processing.

Bulking Cl 3.24

Increase in the bulk volume of a quantity of sand in a moist condition over the volume of the same quantity of dry or completely inundated. 2 IS 6461 (Part 1) : 2024

Bulking Curve Cl 3.25

Graph of change in volume of a quantity of sand due to change in moisture content.

Bulking Factor Cl 3.26

Ratio of the volume of moist sand to volume of the sand when dry.

Cenosphere Cl 3.27

Lightweight aggregate in the form of hollow glass spheres.

Chips Cl 3.28

Broken fragments of marble or other mineral aggregate screened to specified sizes.

Cinder Cl 3.29

Well burnt furnace residue which has b een fused or sintered into lumps of varying sizes. The same material in a finely powdered form is found to possess some pozzolanic activity.

Cobble Cl 3.30

A rock fragment between 64 mm and 256 mm in diameter as applied to coarse aggregate for concrete, the material in the nominal size range 75 mm to 150 mm.

Crushed Gravel Cl 3.31

The product resulting from the artificial crushing of gravel with substantially all fragments having at least one face resulting from fracture.

Crushed Rock Cl 3.32

Coarse aggregate produced by cr ushing rock.

Crushed Stone Cl 3.33

The product resulting from the ar tificial crushing of rocks, boulders or large cobblestones, substantially all faces of which have resulted from the crushing operation.

Dry Rodded Volume Cl 3.34

The volume occupied by an aggregate compacted dry, under standardized conditions used in measuring unit weight of aggregate.

Dry Rodded Weight Cl 3.35

Weight per unit volume of an aggregate compacted dry by rodding under standardized conditions.

Dry Roddi ng Cl 3.36

In measurement of the weight per unit volume of coarse aggregates, the process of compacting dry material in a calibrated container by rodding under standardized conditions.

Elongated Aggregate Cl 3.37

Coarse aggregate consisting of particles that have one dimension significantly larger than the other two.

Expanded Clay Aggregate Cl 3.38

Expanded aggr egate produced from clay.

Expanded Plastic Particle Aggregate Cl 3.39

Exp anded aggregate that consists of plastic particles.

Fineness Modulus Cl 3.40

An empirical factor obtained by adding the total percentages of a sample of the aggregate retained on each of a specified series of sieves, and dividing the sum by 100.

Note — The sieves used are: 150 micron, 300 micron, 600 micron, 1.18 mm, 3.36 mm, 4.75 mm, 10 mm, 20 mm, 40 mm and larger increasing in the ratio of 2 to 1.

Flat Piece Cl 3.42

One in which the ratio of the widt h to thickness of its circumscribing rectangular prism is greater than a specified value.

Free Moisture Cl 3.43

Moisture not retained or absorbed by aggregate.

Fuller’s Curve Cl 3.44

An empirical curve for gradation of aggregates; also known as the Fuller- Thompson ideal grading curve. The curve is designed by fitting either a parabola or an ellipse to a tangent at the point where the aggregate fraction is one-tenth of the maximum size fraction.

Gap Grading Cl 3.45

A particle size distribution in which particles of certain intermediate sizes are wholly or substantially absent.

Grading, Continuous Cl 3.48

A particle size distribution in which all intermediate size fractions are present, as opposed to gap grading.

Grading Curve Cl 3.49

A graphical representation of the percentages of different particle sizes in a material obtained by plotting the cumulative or separate percentages of the material passing through sieves in which the aperture sizes form a given series.

Flaky Aggregate Cl 3.41

Coarse aggregate consisting of particles with a thickness that is small in relation to the other two dimensions. after processing. Definition b) is applied to a portion of an aggregate. Requirements for properties and grading should be stated in specifications. Coarse aggregate resulting from natural disintegration and abrasion of rock or processing of weakly bound conglomerate.

Gravel, Pea Cl 3.51

Screened gravel most of the p articles of which will pass a 10 mm IS sieve and will be retained on a 4.25 mm IS sieve.

Manufactured Fine Aggregate (Manufactured Sand) Cl 3.52

Fine aggregate manufactured from other than natural sources, by processing materials, using thermal or other processes such as separation, washing, crushing and scrubbing.

Mixed Sand Cl 3.53

Fine aggregate produced by blending natural sand and crushed stone sand or crushed gravel sand in suitable proportion.

Particle Shape of Aggregate Cl 3.54

The particle shape of aggregate, such as angular, cubical, elongated and flaky.

Angular Cl 3.54.1

The particles of aggregates p ossessing well defined edges formed at the inter- section of roughly planer faces. And those aggregate that consists of particles with sharp edges.

Cubical Cl 3.54.2

Angular aggregate most of its particles have length, breadth and thickness approximately equal, t hat is the three substantially equal dimensions.

Elongated Piece Cl 3.54.3

The particle of aggregate in which the ratio of length to width of its circumvent rectangular prism is greater than specified value.

Elongation Index Cl 3.54.4

Percentage by weight of particles whose greatest dimensions (length) is greater than one and four-fifths times their mean dimension.

Flaky Material Cl 3.54.5

Particles of aggregate which are usually angular and, of which the thickness is small relative to the width and/or length.

Flakiness Index Cl 3.54.6

The percentage by weight of particles in it whose least dimension (thickness) is less than three-fifths of their mean dimension.

Irregular Aggregate (or Partl y Rounded Aggregate) Cl 3.54.7

Aggregates the particle of which are n aturally irregular, or partly shaped by attrition and have rounded edges. Coarse aggregate that consists of particles with rounded surfaces. In the case of other that natural aggregates, the coarse aggregate that consist of particles of irregular shape and round edges.

Rounded Aggregate Cl 3.54.8

Aggregate, the particles of which are fully water worn or are completely shaped by attrition.

Particle Size Distribution Cl 3.55

The distribution o f particles of granular material among various sizes; usually expressed in terms of cumulative percentages larger or smaller than each of a series of diameters (sieve openings) or the percentages between certain ranges of diameters (sieve openings).

Petrography Cl 3.56

The branch of petrology dealing with description and systematic classification of rocks aside from their geologic relations, mainly by laboratory methods largely chemical and microscopical; also loosely, petrology or lithology.

Petrology Cl 3.57

The science of rocks, treating of their origin, structure, composition, etc, from all aspects and in all relations.

Plum Cl 3.58

A large random shaped stone dropped in to freshly placed mass concrete.

Note — For cyclopean concrete, the weight of each stone may not be les s than 50 kg. For rubble concrete the stone may be such that one man can handle.

Rubble Cl 3.59

Rough stone of irregular shape and size, broken from larger masses by geological process or by quarrying.

Sand Equivalent Cl 3.61

A measure of the amount o f clay contamination in fine aggregate.

Scalper Cl 3.62

A screen for removing oversize particles.

Shingle Cl 3.63

Rounded or water worm stone of ir regular size occurring in river beds or opened beaches.

Sieve Analysis Cl 3.64

Determination of the p roportions of particle lying within certain size ranges in a granular material by separation on sieves of different size openings.

Sieve Correction Cl 3.65

Correction of sieve an alysis to adjust for deviation of sieve performance from that of standard calibrated sieve.

Silica Fume Cl 3.66

Very fine pozzolonic materials composed mostly of amorphous silica produced by electric arc furnaces as a byproduct of the production of elemental silicon or ferro silicon alloys.

Silt Cl 3.67

A granular material resulting from the d isintegration of rock, with grains largely passing a No. 200 ( 75 micron) sieve; alternatively, such particles in the range from 2 microns to 50 microns diameter.

Sinter Cl 3.68

A ceramic material or mixture fired to less than complete fusion, resulting in a coherent mass.

Spall Cl 3.69

A fragment, usually in the shape of a flake, detached from a larger mass by a blow, by the action of weather, by pressure, or by expansion within the larger mass.

Specific Gravity, Saturated Dry Cl 3.70

Basis ― The bulk specific gravity of aggregate determined after complete immersion in water for 24 h and removing surface water.

Stone Sand Cl 3.71

See 3.6.2.

Surface Saturated Dry Cl 3.72

Aggregate ― A co ndition of the aggregate attained after complete immersion in water and removing the superficial water by soaking with cloth.

Surface Water Cl 3.73

Free water retained on surfaces of aggregate particles and considered to be part of the mixing water in concrete, as distinguished from absorbed moisture.