Structural Aspects

IS 6461 (Part 12) — Cement Concrete: Glossary of Terms (First Revision, October 2024) · 2024 definitions.

Part 11Definitions quoted verbatim from the BIS standard

Absolute Specific Gravity Cl 3.1: Ratio of the mass of a given volume of a solid or liquid, referred to a vacuum at a stated temperature to the mass, referred to a vacuum, of an equal volume of gas-free distilled water at a stated temperature (see 3.237).
Acceleration Cl 3.2: Increase in velocity or in rate of change, especially the quickening of the natural progress of a process, such as hardening, setting, or strength development of concrete.
Accidental Air Cl 3.3: Air voids in concrete which are not purposely entrained.
Additive Cl 3.4: A material that is interground or blended in limited amounts into a hydraulic cement during manufacture either as a processing addition to aid in manufacturing and handling the cement or as a functional addition to modify the used properties of the finished product.
Adiabatic Cl 3.5: A condition in which hea t neither enters nor leaves a system.
Adiabatic Curing Cl 3.6: The maintenance of adiabatic conditions in concrete or mortar during the curing period.
Adsorbed Water Cl 3.7: Water held on surfaces of a material by electrochemical forces and having physical properties substantially different from those of absorbed water or chemically combined water at the same temperature and pressure.
Air Entraining Cl 3.8: The capability of a material or process to develop a system of minute bubbles of air in cement paste, mortar, or concrete.
Air Void Cl 3.9: A space in cement paste, mortar or concrete filled with air; an entrapped air void is characteristically 1 mm or more.
Anchor Bolt Cl 3.10: A bolt with the threaded portion projecting from a structure, generally used to hold the frame of a building secure against wind load or a machine against the forces of vibration; known also as hold-down bolt and foundation bolt.
Angle of Repose Cl 3.11: The angle between the horizontal and the natural slope of loose material below which the material will not slide.
Apparent Specific Gravity Cl 3.12: See 3.237.
Arc Spectrography Cl 3.13: Spectrographic identification of elements in a sample of material, heated to volatilization in an electric arc or spark.
Arenaceous Cl 3.14: Composed primarily of sand ; sandy.
Argillaceous Cl 3.15: Composed primarily of clay or shale; clayey.
Bacterial Corrosion Cl 3.16: The destruction of a material by chemical processes brought about by the activity of certain bacteria which may produce substances, such as hydrogen sulphide, ammonia, and sulphuric acid.
Bag (of Cement, also Sack) Cl 3.17: A quantity of Portland cement, 50 kg in India and most countries using the metric system. For other kinds of cement, the quantity indicated on the packing or container. 1 IS 6461 (Part 12) : 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/
Ball Mi ll Cl 3.18: Horizontal, cylindrical, rotating mill charged with large grinding media.
Barrel Cl 3.19: vault Roof — A thin concrete roof taking the form of a part of a cylinder.
Base Cl 3.20: A subfloor slab or ‘working mat’, either previously placed and hardened or freshly placed, on which floor topping is placed in a later operation; also the under -lying stratum on which a concrete slab, such as a pavement, is placed.
Base Coat Cl 3.22: Any plaster coat or coats applied prior to application of the finish coat.
Base Plate Cl 3.23: A plate of metal or other approved material formerly placed under pavement joints and the adjacent slab ends to prevent the infiltration of soil and moisture from the sides or bottom of the joint opening. Also a device used to distribute vertical loads as for building columns or machinery.
Base Screed Cl 3.24: A preformed metal screed with perforated or expanded flanges to provide a ground for plaster and to separate areas of dissimilar materials.
Batch Cl 3.25: Quantity of concrete or mortar mixed at one time.
Batch Box Cl 3.26: Container of known volume used to measure constituents of a batch of concrete or mortar in proper proportions.
Batter Cl 3.27: Inclination from the vertical or horizontal.
Batter Boards Cl 3.28: Pairs of horizontal boards nailed to wood stakes adjoining an excavation, used as a guide to elevations and to outline the building.
Beam Bottom Cl 3.29: Soffit or bottom form for a beam.
Beam Pocket Cl 3.30: Opening left in a vertical member in which a beam is to rest; also an opening, in the column or girder from where forms for an intersecting beam will be framed.
Belt Sleave Cl 3.31: A tube surrounding a bolt in a concrete wall to prevent concrete from sticking to the bolt and acting as a spreader for the formwork.
Beneficiation Cl 3.32: Improvement of the chemical or physical properties of a raw material or intermediate product by the removal of undesirable components or impurities.
Bent Cl 3.33: Two-dimensional frame which is self- supporting within these dimensions, having at least two legs and usually placed at right angles to the length of the structure which it supports.
Bentonite Cl 3.34: A clay composed principally of minerals of the montmorillonite group, characterized by high adsorption and very large volume change with wetting or drying.
Berliner (Crazy) Cl 3.35: A type of terrazzo topping using small and large pieces of marble paving, usually with a standard terrazzo matrix between pieces.
Blaine Fineness Cl 3.36: The fineness of powdered materials, such as cement and pozzolana, expressed as surface area usually in m2/kg.
Blistering Cl 3.37: The irregular raising of a thin layer at th e surface of placed mortar or concrete during or soon after completion of the finishing operation, or in the case of pipe after spinning; also bulging of the finish plaster coat as it separates and draws away from the base coat.
Blow Out Cl 3.38: Remove unwanted materials from inside formwork with compressed air.
Board Butt Joint Cl 3.39: Shotcrete construction joint fo rmed by sloping gunned surface to a 25 mm board, laid flat.
Block Beam Cl 3.40: A flexural member composed of individual blocks which are joined together by prestressing.
Brace Cl 3.41: Structural member used to provide lateral support for another member, generally for the purpose of ensuring stability or resisting lateral loads.
Bredigite Cl 3.42: A mineral, alpha prime dicalcium silicate (2C aO.SiO2) occurring naturally or in slags and Portland cement.
Brownmillerite Cl 3.43: A ternary comp ound originally regarded as 4CaO.AI 2O3.Fe2O3, (C 4AF) occurring in Portland cement and high alumina cement; now used to refer to a series of solid solutions between 2CaO.Fe 2O3 (C2F) and 2CaO.AI2O3 (C2A).
Bulk Density Cl 3.44: The weight of a material (includin g solid particles and any contained water) per unit volume including voids.
Bulking Cl 3.45: Increase in the bulk volume of a quantity of sand in a moist condition over the 2 IS 6461 (Part 12) : 2024 volume of the same quantity, dry or completely inundated.
Bulking Curve Cl 3.46: Graph of charge in volume of a quantity of sand due to change in moisture content.
Bulking Factor Cl 3.47: Ratio of the volume of moist sand to the volume of the sand when dry.
Bulk Loading Cl 3.48: Loading of unbagged cement in containers, specially designed trucks, railroad cars or ships.
Bulk Specific Gravity Cl 3.49: See 3.237.
Butyl Stearate Cl 3.50: A colourless oleaginous, practically odourless material (C17 H35 COOC4H9) used as a damp-proofer for concrete.
Cage Cl 3.51: A rigid assembly of reinforcement ready for placing in position.
Caisson Pile Cl 3.52: A cast-in-place pile made by driving a tube, excavating it, and filling the cavity with concrete.
Calcareous Cl 3.53: Containing calcium carbonate or, less generally, containing the element calcium.
Calcine Cl 3.54: To alter composition or physical state by heating below the temperature of fusion.
Calcite Cl 3.55: A mineral having the composition calcium carbonate (CaCO3) and a specific crystal structure, the principal constituent of limestone, chalk, and marble; usually a major raw material used in Portland cement manufacture.
Capillarity Cl 3.56: The movement of a liquid in the interstices of soil or other porous material due to surface tension.
Capillary Flow Cl 3.57: Flow of moisture through a capillary pore system, such as in concrete.
Capillary Space Cl 3.58: In cement paste, any space not occupied by anhydrous cement or cement gel (air bubbles, whether entrained or entrapped, are not considered to be part of the cement paste).
Carbonation Cl 3.59: Reaction between carbon dioxide and calcium compounds, especially in cement paste, mortar, or concrete, to produce calcium carbonate.
Cast Cl 3.60: in-Place Pile — A concrete pile concreted either with or without a casing in its permanent location, as distinguished from a precast pile.
Celite Cl 3.61: A name used to identify the calcium alumino ferrite constituent of Portland cement.
Cement Aggregate Ratio Cl 3.62: The ratio, by weigh t or volume, of cement to aggregate.
Cementation Process Cl 3.63: The process of injectin g cement grout under pressure into certain types of ground, for example, gravel, fractured rock to solidify it.
Cement Bacillus Cl 3.64: A mineral, high sulphate calcium sulfoaluminate (3CaO Al2O3 3CaSO4.30-32 H2O); occurring naturally or formed by sulphate attack on mortar and concrete.
Cement Bituminous Cl 3.65: A black solid, semisolid, or liquid substance at natural air temperatures and appreciably soluble only in carbon disulphide or some volatile liquid hydrocarbon, being composed of mixed in determinate hydrocarbons mixed from natural deposits. Produced as a residue in the distillation of petroleum or obtained by the destructive distillation of coat or wood.
Cement Clinker Cl 3.66: Nodules of cementitious compound, emerging from shaft, rotary kiln or any sintering device, which is ground to make cement.
Cement Gel Cl 3.67: The colloidal material that mak es up the major portion of the porous mass of which mature hydrated cement paste is composed.
Cementitious Cl 3.68: Having cementing properties.
Cement Paint Cl 3.69: A paint consisting generally of white Portland cement and water, pigments, hydrated lime, water repellents, or hygroscopic salts.
Cement Paste Cl 3.70: A mixture of cement and water; may be either hardened or unhardened.
Cement Plaster Cl 3.71: Plaster containing Portland cem ent.
Cement Rock Cl 3.72: Natural impure limestone which contains the ingredients for production of Portland cement in approximately the required proportions.
Ceramic Bond Cl 3.73: The development of fired str ength as a result of thermo-chemical reactions between materials exposed to temperatures approaching the fusion point of the mixture such as that which may occur, under these conditions, between calcium-aluminate cement and a refractory aggregate. 3 IS 6461 (Part 12) : 2024
Chalk Cl 3.74: A soft limestone composed chiefly of the calcareous remains of marine organisms.
Chalking Cl 3.75: Disintegration of coatings, such as a cement paint, manifested by the presence of a loose powder evolved from the paint at, or just beneath, the surface.
Chamfer Cl 3.76: A bevelled corner which is formed in concrete work by placing a chamfer strip in the corner of the form.
Chemical Bond Cl 3.77: Bond between materials that is the result of cohesion and adhesion developed by chemical reaction.
Chipping Cl 3.78: Treatment of a hardened concrete surface by chiseling.
Clay Content Cl 3.79: Percentage of clay by dry weight of a heterogeneous material, such as a soil or a natural concrete aggregate.
Coat Cl 3.80: A film or layer as of paint or plaster applied in a single operation.
Coating Cl 3.81: Material applied to surface by brushing, dipping, mopping, spraying, trowelling, etc, such as to preserve, protect, decorate, seal, or smooth the substrate.
Coefficient of Linear Thermal Expansion Cl 3.82: Length change per unit of length per degree of temperature change.
Coefficient of Subgrade Reaction Cl 3.83: An experimentally determined ratio between the vertical subgrade reaction and the deflection at a point on the surface of contact.
Coefficient of Thermal Expansion Cl 3.84: Change in linear dimension per unit length or change in volume per unit volume per degree of temperature change.
Cold Cl 3.85: water Paint — A paint in which the binder or vehicle portion is composed of latex, casein, glue or some similar material dissolved or dispersed in water.
Composite Sample Cl 3.86: Sample obtained by blending two or more individual samples of a material.
Concrete Cl 3.87: A composite material which consists essentially of a binding medium within which are embedded particles or fragments of aggregate; in Portland cement concrete, the binder is a mixture of Portland cement, any admixture approved by the engineer-in-charge and water.
Concrete Casing Cl 3.88: Protective concrete covering to structural steel.
Concrete Pile Cl 3.89: A precast reinforced or prestressed concrete pile driven into the ground by a pile driver or otherwise placed.
Conductivity, Thermal Cl 3.90: A property of a homogeneous body measured by the ratio of the steady state heat flux (time rate of heat flow per unit area) to the temperature gradient (temperature difference per unit length of heat flow path) in the direction perpendicular to the area.
Construction, Composite Cl 3.91: Construction co nsisting of cast- in-place reinforced concrete and members made of some other material so interconnected that the component elements act together as a unit.
Cover Block Cl 3.92: Device which maintains reinforcement in proper position, or wall forms at a given distance apart, before and during concreting.
Crack Control Cl 3.93: Ensure that any crack in concrete occur in predetermined positions or of controlled width.
Cross Nicols Cl 3.94: Two Nicol prisms placed so th at their vibration planes of transmitted light are mutually at right angles.
C/S Ratio Cl 3.95: The molar or weight ratio, wh ichever is specified, of calcium oxide to silicon dioxide; usually of binder materials cured in an autoclave.
Deflection Cl 3.96: In general, an angular variation f rom an established direction or plane, usually measured as a linear deviation from an established plane rather than an angular variation.
Deformation Cl 3.97: A change in dimensions or s hape due to stress.
Dehydration Cl 3.98: Removal of chemically bound o r adsorbed water from a material.
Density Cl 3.99: Weight per unit volume.
Density Control Cl 3.100: Control of density of co ncrete in field construction to insure that specified values as determined by standard tests are obtained.
Density (Dry) Cl 3.101: The dry weight of a s ubstance per unit volume at a stated temperature.
Deterioration Cl 3.102: Disintegration into small fragments or particles due to any cause. 4 IS 6461 (Part 12) : 2024
Diatomaceous Earth Cl 3.103: A friable earthy material composed primarily of nearly pure hydrous amorphous silica (opal) and consisting essentially of the frustules of the microscopic plants called diatoms.
Dicalcium Silicate Cl 3.104: A co mpound having the composition 2 CaO.SiO2, abbreviated C 2S, that occurs in Portland-cement clinker.
Differential Thermal Analysis (DTA) Cl 3.105: Indication of thermal reaction by differential thermocouple recording of temperature changes in a sample under investigation compared with those of a chemically passive control sample, that is heated uniformly and simultaneously.
Diffusivity, Thermal Cl 3.106: Thermal conductivity divided by the product of specific heat and unit weight; an index of the facility with which a material undergoes temperature change.
Diluent Cl 3.107: A substance, liquid or solid, mixed with the active constituents of a formulation to increase the bulk or lower the concentration.
Discolouration Cl 3.108: Departure of colour from that which is normal or designed.
Disintegration Cl 3.109: See 3.102.
Dispersant Cl 3.110: A material which deflocculates or disperses finely ground materials by satisfying the surface energy requirements of the particles; used as a slurry thinner or grinding aid.
Dispersing Agent Cl 3.111: An addition or admix ture capable of increasing the fluidity of pastes, mortars, or concrete by reduction of inter- particle attraction.
Dried Strength Cl 3.113: The compressive or flexural strength of refractory concrete determined with 3 h after first drying in an oven at 105 °C to 110 °C for a specified time.
Dry Process Cl 3.114: In the manufacture of cement, the process in which the raw materials are ground, conveyed, blended, and stored in a dry condition.
Ductility Cl 3.115: That property of a material by virtue of which it may undergo large permanent deformation without rupture.
Dummy Joint Cl 3.116: A construction joint created by forming a groove in the surface of a pavement, floor slab, or wall to control random cracking.
Earth Pigments Cl 3.117: The class of pigments which are produced by physical processing of materials mined directly from the earth; also frequently termed natural or mineral pigments or colours.
Efflorescence Cl 3.118: A deposit of salts, usually white, formed on a surface, the substance having emerged from below the surface.
Emulsifier Cl 3.119: A substance which modifies the s urface tension of colloidal droplets, keeping them from coalescing, and keeping them suspended.
Endothermic Cl 3.120: Pertaining to a reaction which occurs with the absorption of heat.
Epoxy Resins Cl 3.121: A class of chemical bonding systems used in the preparation of special coatings or adhesives for concrete or as binders in epoxy- resin mortars and concretes.
Erosion Cl 3.122: Deterioration brought about by the ab rasive action of fluids or solids in motion.
Evaporable Water Cl 3.124: Water in set cement paste present in capillaries or held by surface forces; measured as that removable by drying under specified conditions.
Exothermic Cl 3.125: Pertaining to a reaction which occu rs with the evolution of heat.
Extensibility Cl 3.126: The maximum tensile strain that h ardened cement paste, mortar, or concrete can sustain before cracking occurs.
False Set Cl 3.127: The rapid development of rigid ity in a freshly mixed Portland cement paste, mortar, or concrete without the evolution of much heat, which rigidity can be dispelled and plasticity regained by further mixing without addition of water; premature stiffening, hesitation set, early stiffening, and rubber set are terms referring to the same phenomenon, but false set is the preferred designation.
Felite Cl 3.128: A name used by Tornebohm (1897) to iden tify one form of dicalcium silicate 5 IS 6461 (Part 12) : 2024 (2CaO.SiO2), one of the crystalline components of Portland cement clinker.
Fire Strength Cl 3.129: The compressive or flexural strength of refractory concrete determined after first firing to a specified temperature for a specified time and subsequent cooling.
Fired Unit Weight Cl 3.130: The unit weight of ref ractory concrete after having been exposed to a specified firing temperature for a specified time and subsequent cooling.
Frame or Panel Cl 3.132: The principal pr efabricated, welded structural unit in a scaffolding tower; also beam and column skeleton of a building.
Gel Cl 3.133: Matter in a colloidal state that does not dissolve but remains suspended in a solvent from which it fails to precipitate without the intervention of heat or of an electrolyte.
Grog Cl 3.134: Burned refractory material, usually calcin ed clay or crushed brick bats.
Grout Cl 3.135: Mixture of cementitious material and aggregate to which sufficient water is added to produce pouring consistency without segregation, segregation of the constituents, or mixtures of other compositions, such as containing PVC or epoxy resin or sodium silicate, but similar consistency.
Gupman Cl 3.136: Workman on shotcreting crew who operates delivery equipment.
Heat of Hydration Cl 3.137: Heat evolved by chemical reactions with water, such as that evolved during the setting and hardening of Portland cement (see also 3.138); the difference between the heat of solution of dry cement and that of partially hydrated cement.
Heat of Solution Cl 3.138: Heat evolved by the solution of material in a solvent.
Heavy Cl 3.139: Media Separation — A method in which a liquid or suspension of given specific gravity is used to separate particles into a portion lighter than (those that float) and a portion heavier than (those that sink) the medium.
Hemihydrate Cl 3.140: A hydrate containing one- half molecule of water to one molecule of compound; the most commonly known hemihydrate is partially dehydrated gypsum (plaster of Paris, CaSO4 1 2 H2O).
Honeycombing Cl 3.141: The process of formation of voids/cavities in concrete due to improper compaction or loss of slurry through the formwork.
Hot Face Cl 3.142: The surface of a refractory sec tion exposed to the source of heat.
Hot Load Test Cl 3.143: A test for determining the resistance to deformation or shear of a refractory material when subjected to a specified compressive load at a specified temperature for a specified time.
Hydrate Cl 3.144: A chemical combination of water with another compound or an element.
Hydration Cl 3.145: Formation of a compound by the combining of water with some other substance; in concrete, the chemical reaction between cement and water.
Hydraulic Properties Cl 3.146: Hydraulic pr operties are the ability of a material to set and harden in the presence of water, with formation of stable compounds.
Isotropy Cl 3.147: The behaviour of a medium having the same properties in all directions.
Joint Filler Cl 3.148: Material used to fill a joint to pr event the infiltration of debris.
Joint Sealant Cl 3.149: Material used to exclude water and solid foreign materials from joints.
Liquid Cl 3.150: Volume Measurement — Measur ement of grout on the basis of the total volume of solid and liquid constituents.
Macroscopic Cl 3.151: Visible to the unaided eye.
Marl Cl 3.152: Calcareous clay, usually containing from 35 percent to 65 percent calcium carbonate (CaCO3), found in the bottoms of shallow lakes, swamps, or extinct fresh water basins.
Masonry Mortar Cl 3.153: Mortar used in masonry str uctures.
Matrix Cl 3.154: In the case of mortar, the cement paste in which the fine aggregate particles are embedded; in the case of concrete, the mortar in which the coarse aggregate particles are embedded.
Megascopic Cl 3.155: See 3.151.
Melilite Cl 3.156: A group of minerals ranging from the calcium magnesium silicate, ackermanite, to the calcium aluminate silicate, gehlenite, that occur as crystals in blast-furnace slag. 6 IS 6461 (Part 12) : 2024
Membrane Curing Cl 3.157: A process that involves either liquid sealing compound ( for example, bituminous and paraffinic emulsions, coal tar cutbacks, pigmented and non -pigmented resin suspensions, or suspensions of wax and drying oil) or non-liquid protective coating (for example, sheet plastics or waterproof paper), both of which types function as films to restrict evaporation of mixing water from the fresh concrete surface.
Micron Cl 3.158: A unit of length; one-thousandth of a millimeter or one-millionth of a metre.
Microscopic Cl 3.159: Discernible only with the aid of a microscope.
Modulus of Subgrade Reaction Cl 3.160: An experimentally determined ratio between the vertical subgrade reaction and the deflection at a point on the surface of contact.
Monolith Cl 3.161: A body of plain or reinforced concrete cast or erected as a single integral mass or structure.
Montmorillonite (or Montmorillonoid) Cl 3.162: A group of clay minerals, including montmorillonite, characterized by a sheet like internal molecular structure; consisting of extremely finely-divided hydrous aluminum or magnesium silicates that swells on wetting, shrink on drying, and are subject to ion exchange.
Mould Cl 3.163: A device containing a cavity into which neat cement, mortar, or concrete test specimens are cast; or a form used in the fabrication of precast mortar or concrete units (for example, masonry units).
Nailer Cl 3.164: A strip of wood or other fitting attached to or set in concrete, or attached to steel to facilitate making nailed connections.
Neat Cement Cl 3.165: Hydraulic cement in the unhydrated state.
Neat Line Cl 3.166: A line defining the proposed or specified limits of an excavation or structure.
Nicol Prism Cl 3.167: A system of two optically clear crystals of calcide (Iceland spar) used in producing plane-polarized light.
Non Cl 3.168: evaporable Water — The water that is chemically combined during cement hydration; not removable by specified drying.
Ocrate Process (Trade Name) Cl 3.169: The trea tment of concrete with gaseous SiF4 to transform any free CaO into CaF3.
Offset Cl 3.170: A horizontal ledge occurring along a change in wall thickness; the narrow flat surface (or shelf) created by reducing the thickness of the wall above.
Ovals Cl 3.171: Marble chips which have been tumbled until a smooth oval shape has resulted.
Packer Cl 3.172: head Process — A method of casting concrete pipe in a vertical position in which concrete of low water content is compacted with a revolving compaction tool.
Pack Set Cl 3.173: Finished cement which develops low or zero flowability during or after storage in silos, or after transporation in bulk containers, hopper-bottom cars, etc; may be caused by: a) interlocking of particles; b) mechanical compaction; and c) electrostatic attraction between particles.
Petrography Cl 3.175: 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 3.176: The science of rocks, treating of their origin , structure and composition from all aspects and in all relations.
Phenolic Resin Cl 3.177: A class of synthetic, oil - soluble resins (plastics) produced as condensation products of phenol, substituted phenols and formaldehyde, or some similar aldehyde that may be used in paints for concrete.
Pigment Cl 3.178: A colouring matter, usually in the form of an insoluble fine powder.
Plaster Cl 3.179: A cementitious material or combination of cementitious material and aggregate that, when mixed with a suitable amount of water, forms a plastic mass or paste which when applied to a surface, adheres to it and subsequently hardens, preserving in a rigid state the form or texture imposed during the period of plasticity; also the placed and hardened mixture.
Plaster of Paris Cl 3.180: Gypsum ( CaSO4.2H2O) from which three quarters of the chemically bound water has been driven off by heating; when wetted it recombines with water and hardens quickly.
Plastic Cl 3.181: Possessing plasticity, or possessing adequate plasticity. 7 IS 6461 (Part 12) : 2024
Plastic Mortar Cl 3.182: A mortar of plastic consistency.
Plasticizing Cl 3.183: Producing plasticity or becoming plastic.
Plastic or Bond Fire Clay Cl 3.184: A fire clay of sufficient natural plasticity to bond non -plastic material; a fire clay used as a plasticizing agent in mortar.
Plumb Cl 3.185: Vertical or to make vertical.
Plumbing Tool Cl 3.186: Device attached to the foot of a soldier to enable the formwork for a wall to be plumbed.
Polish or Final Grind Cl 3.187: The final operation in which fine abrasives are used to hone a surface to its desired smoothness and appearance.
Polyethylene Cl 3.188: A thermoplastic high - molecular-weight organic compound used in formulating protective coatings or, in sheet form, as a protective cover for concrete surfaces during the curing period, or to provide a temporary enclosure for construction operations.
Polymer Cl 3.189: The product of polymerization; more commonly a rubber or resin consisting of large molecules formed by polymerization.
Polymerization Cl 3.190: The reaction in which two or more molecules of the same substance combine to form a compound containing the same elements, and in the same proportions, but of high molecular weight, from which the original substance can be regenerated, in some cases only w ith extreme difficulty.
Polystyrene Resin Cl 3.191: Synthetic resins varying in colour from water white to yellow formed by the polymerization of styrene on heating with or without catalysts that may be used in paints for concrete, or for making sculptured moulds, or as insulation.
Polysulphide Coating Cl 3.192: A protective coating system prepared by polymerizing a chlorinated alkyl polyether with an inorganic polysulphide, exhibits outstanding resistance to ozone, sub-light, oxidation, and weathering.
Polyurethane Cl 3.193: Reaction product of an isocyanate with any of a wide variety of other compounds containing an active hydrogen group; used to formulate tough, abrasion resistant coatings.
Polyvinyl Acetate Cl 3.194: Colourless, permanently thermoplastic resin; usually supplied as an emulsion or water -dispersible powder characterized by flexibility, stability towards light, transparency to ultraviolet rays, high dielectric strength, toughness, and hardness; the higher the degree of polymerization, the higher the softening temperature; may be used in paints for concrete.
Polyvinyl Chloride Cl 3.195: A synthetic resin prepared by the polymerization of vinyl chloride, used in the manufacture of nonmetallic waterstops for concrete.
Porosity Cl 3.196: The ratio, usually expressed as a per centage, of the volume of voids in a material to the total volume of the material, including the voids.
Pot Life Cl 3.197: Time interval after mixing during which liquid material is usable with no difficulty.
Pozzolana Cl 3.198: An essentially silicious material which while in itself possessing little or no cementitious properties will, in finely divided form and in the presence of water, react with calcium hydroxide at ambient temperature to form compounds possessing cementitious properties. The term includes natural volcanic material having pozzolanic properties as also other natural and artificial materials, such as diatomaceous earth, calcined clay and fly ash.
Pozzolana Mortar Cl 3.199: A lime or cement mor tar in which pozzolana has been used.
Pozzolanic Material Cl 3.200: These materials which have the pozzolanic activity of combining with lime to form cementitious compounds.
Pozzolanic Properties Cl 3.201: The ability of a material to combine chemically with calcium hydroxide in the presence of water under ambient temperature forming compounds having cementitions properties.
Prefiring Cl 3.202: Raising the temperature of ref ractory concrete under controlled conditions prior to placing it in service.
Preformed Foam Cl 3.203: Foam produced in a form generator prior to introduction of the foam into a mixer with other ingredients to produce cellular concrete.
Primary Nuclear Vessel Cl 3.204: Interior container in a nuclear reactor designed for sustained loads and for working conditions.
Promoter Cl 3.205: A substance that accelerates or causes a chemical reaction without itself being transformed by the reaction. 8 IS 6461 (Part 12) : 2024
Push Cl 3.206: Pull Drop — Adjustable formwork support that transmits tensile or compressive loads.
Pyrometric Cone Cl 3.207: A small, slender, three- sid ed oblique pyramid made of ceramic or refractory material for use in determining the time temperature effect of heating and in obtaining the pyrometric cone equivalent (PEC) of refractory material.
Quartering Cl 3.208: A method of obtaining a representative sample by dividing a circular pile of a larger sample into four equal parts and discarding opposite quarters successively until the desired size of sample is obtained.
Raw Mix Cl 3.209: Blend of raw materials, ground to desired fineness, correctly proportioned, and blended ready for burning; such as that used in the manufacture of cement clinker.
Reactive Silica Material Cl 3.210: Several types of materials which react at high temperatures with Portland cement or lime during autoclaving; includes pulverized silica, natural pozzolana, and fly ash.
Refractories Cl 3.211: Materials, usually nonmetallic, used to withstand high temperatures.
Refractoriness Cl 3.212: In refractor ies, the property of being resistant to softening or deformation at high temperatures.
Refractory Cl 3.213: Resistant to high temperatures.
Reglet Cl 3.214: A groove in a wall to receive flashing.
Reinforced Masonry Cl 3.215: Unit masonry in which reinforcement is embedded in such a manner that the two materials act together in resisting forces.
Relative Humidity Cl 3.216: The ratio of the quantity of water vapour actually present to amount present in a saturated atmosphere at a given temperature; expressed as a percentage.
Rheology Cl 3.217: The science dealing with flow of materials, including studies of deformation of hardened concrete, the handling and placing of freshly mixed concrete, and the behaviour of slurries, pastes, and the like.
Santorin Earth Cl 3.219: A volcanic tuff used as a pozzolana.
Scoria Cl 3.220: Volcanic rock characterized by a vesicular texture and dark colour; particles between 4 mm and 32 mm are essentially equivalent to volcanic cinders.
Sealing Compound Cl 3.221: Material used to exclude water and solid foreign materials from joints.
Secondary Nuclear Vessel Cl 3.222: Exterior container or safety container in a nuclear reactor subjected to design load only once in its lifetime.
Settling Cl 3.223: The lowering in elevation of sections of pavement or structures due to their weight, the loads imposed on them, or shrinkage or displacement of the supporting earth.
Shelf Life Cl 3.224: Maximum interval during which a material may be stored and remain in a usable condition.
Shell Construction Cl 3.225: Construction using thin curved slabs.
Shrinkage Cl 3.226: Compensating — A characteristic of grout, mortar, or concrete made using an expansive cement in which volume increase if restrained, induces compressive stresses which are intended to approximately offset the tendency of drying shrinkage to induce tensile stresses.
Silica Cl 3.227: Silicon dioxide (SiO2).
Silica Flour Cl 3.228: A siliceous binder component which reacts with lime under autoclave curing conditions; prepared by grinding quartz to the fineness of Portland cement.
Silicate Cl 3.229: Salt of a silicic acid.
Skew Back Cl 3.230: Sloping surface against which the end of an arch rests, such as a concrete thrust block supporting thrust of arch bridge.
Slop Cl 3.231: The waste material produced in the wet grinding process and consisting of finely ground terrazzo and water.
Sludge Cl 3.232: See 3.231.
Solid Volume Cl 3.233: The displacement volume of an ingredient of concrete or mortar; in the case of solids, the volume of the particles themselves, including their permeable and impermeable voids but excluding space between particles; in the case of fluids, the cubic content which they occupy.
Solution Cl 3.234: A liquid of at least two substances, one of which is a solvent in which the other or others are dissolved. 9 IS 6461 (Part 12) : 2024
Solvent Cl 3.235: A liquid in which another substance may be dissolved.
Soundness Cl 3.236: The freedom of a solid from crack s, flaws fissures, or variations from an accepted standard; in the case of cement, freedom from excessive volume change after setting; in the case of aggregate, the ability to withstand the aggressive action to which concrete containing it might be exposed particularly that due to weather.
Specific Gravity Cl 3.237: The ratio of the mass of a unit volume of a material at a stated temperature to the mass of the same volume of gas-free distilled water at a stated temperature: a) Apparent Specific Gravity — The ratio of the mass in air of a unit volume of a material at a stated temperature to the mass in air at equal density of an equal volume of gas-free distilled water at a stated temperature. If the material is a solid, the volume is that of the impermeable portion; b) Bulk Specific Gravity — The ratio of the mass in air of a unit volume of a permeable material (including both permeable and impermeable voids normal to the material) at a stated temperature to the mass in air of equal density of an equal volume of gas-free distilled water at a stated temperature; and c) Bulk (Saturated-Surface-Dry Basis) Specific Gravity — Same as bulk specific gravity except that the mass includes the water in the permeable voids (see also 3.1).
Specific Surface Cl 3.238: The surface area of particles contained in a unit weight or absolute unit volume of a material.
Spraying Drying Cl 3.239: A method of evaporating the liq uid from a solution by spraying it into a heated gas.
Stabilizer Cl 3.240: A substance which makes a solution or suspension more stable, usually by keeping particles from precipitating.
Sticky Cement Cl 3.241: See 3.173.
Stockhouse Setting Cl 3.242: See 3.173.
Stress Corrosion Cl 3.243: Corrosion of a metal acceler ated by stress.
Stucco Cl 3.244: A plaster used for coating exterior walks and other exterior surfaces of buildings.
Subbase Cl 3.245: A layer in a pavement system between the subgrade and base course or between the subgrade and a Portland cement concrete pavement.
Subgrade Cl 3.246: The soil prepared and compacted to support a structure or a pavement system.
Sulphate Attack Cl 3.247: Harmful or deleterious chemical or physical reaction or both between sulphates in soil or ground water and concrete or mortar, primarily the cement-paste matrix.
Sulphate Resistance Cl 3.248: Ability of concrete or mortar to withstand sulphate attack.
Surface Active Cl 3.249: Having the ability to modify surface energy and to facilitate wetting, penetrating, emulsifying, dispersing, solubilizing, foaming, frothing, etc of other substances.
Surface Area Cl 3.250: See 3.238.
Surface Voids Cl 3.251: Cavities visible on the surface of a solid.
Temperature Rise Cl 3.252: The increase of temperature caused by absorption of heat or internal generation of heat, as by hydration of cement in concrete.
Temperature Cl 3.253: Rise Period — The time interval during which the temperature of a concrete product rises at a controlled rate to the desired maximum in autoclave or atmospheric pressure steam curing.
Tetracalcium A luminoferrite Cl 3.254: A compound in the calcium aluminoferrite series, having the composition 4CaO Al 2O3 Fe2O3, abbreviated C 4AF, which is usually assumed to be the aluminoferrite present when compound calculations are made from the results of chemical analysis of Portland cement.
Thermal Diffusivity Cl 3.256: See 3.106.
Thermoplastic Cl 3.257: Becoming soft when heated and hard when cooled.
Thermosetting Cl 3.258: Becoming rigid by chemical reaction and not remeltable.
Thixotropy Cl 3.259: The property of a material that enables it to stiffen in a short period on standing, but 10 IS 6461 (Part 12) : 2024 to acquire a lower viscosity on mechanical agitation, the process being reversible; a material having this property is termed thixotropic or shear thinning.
Tieback Cl 3.260: A steel rod fastened to a deadman or a rigid foundation to prevent the lateral movement of formwork, sheet pile walls, retaining walls, etc.
Timber Stresses Cl 3.261: Stresses for stress-grade lumber conforming to recognized values.
Time Cl 3.262: Dependent Deformation — Combined effects of autogenous volume change, contraction, creep, expansion, shrinkage, and swelling occurring during an appreciable period of time; not synonymous with ‘inelastic behaviour’ or ‘volume change’.
Tolerance Cl 3.263: The permitted variation from a given dimension or quantity.
Toughness Cl 3.264: The property of matter which resists fracture by impact or shock.
Triaxial Compression Test Cl 3.265: A test in which a specimen is subjected to a confining hydrostatic pressure and then loaded axially to failure.
Triaxial Test Cl 3.266: A test in which a specimen is subjected simultaneously to lateral and axial loads.
Unsound Cl 3.267: Not sound (see also 3.236).
Vapour Pressure Cl 3.268: A component of atmospheric pressure which is caused by the presence of vapour, expressed in centimeters, or millimeters of high of a column of mercury.
Vehicle Cl 3.269: Liquid carrier; binder; anything dis solved in the liquid portion of a paint is a part of the vehicle.
Veneer Cl 3.270: A masonry facing which is attach ed to the backup but not so bonded as to act with it under load.
Vermiculite Cl 3.271: A group name for certain platy minerals, hydrous silicates of aluminium, magnesium, and iron; characterized by marked exfoliation on heating; also a constituent of clays.
Viscosity Cl 3.272: Friction within a liquid due to mutual adherence of its particles.
Void Cl 3.273: Cement Ratio — Volumetric ratio of air plus water to cement.
Volatile Material Cl 3.274: Material that is subject to r elease as a gas or vapour, liquids that evaporate readily.
Warehouse Set Cl 3.275: The partial hydration of cem ent stored for periods of time and exposed to atmospheric moisture.
Waterproofing Compound Cl 3.276: Material used to impart water repellency to a structure or a construction unit.
Waterstop Cl 3.277: A thin sheet of metal, rubber, plast ic, or other material inserted in a construction joint to obstruct the seeping of water through the joint.
Water Void Cl 3.278: Space in hardened concrete occupied or formed by surplus water.
Wetting Agent Cl 3.279: A substance capable of lowering the surface tension of liquids, facilitating the wetting of solid surfaces and permitting the penetration of liquids into the capillaries.
Wythe (Leaf) Cl 3.280: Each continuous vertical sec tion of a wall one masonry unit in thickness.
Xonotlite Cl 3.281: A crystallized monocalcium silicate hydrate which can be synthesized at steam pressures of about 14 kg/cm 2 to 16 kg/cm2 gauge or higher.
X Cl 3.282: ray Diffraction — The diffraction of X-rays by substances having a regular arrangement of atoms; a phenomenon used to identify substances having such structure.
X Cl 3.283: ray Fluorescence — Characteristic sec ondary radiation emitted by an element as a result of excitation by X-rays, used to yield chemical analysis of a sample.
Yellowing Cl 3.284: Development of yellow colour or cast in white or clear coatings, on aging.

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