GB/T 4131-2014Nomenclature and terminology of cement (English PDF)

2 Classification

2.1 By use and performance cement is divided into general purpose cement, the cement commonly used in ordinary civil engineering and building works, and special cement, cement with a special performance or a special use.

2.2 By the name of its principal hydraulic mineral cement is divided mainly into: portland cement, whose principal hydraulic minerals are tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium alumino-ferrite; calcium aluminate cement, whose principal hydraulic mineral is calcium aluminate; calcium sulpho-aluminate cement, whose principal hydraulic minerals are anhydrous calcium sulpho-aluminate and dicalcium silicate; calcium ferro-aluminate cement, whose principal hydraulic minerals are anhydrous calcium sulpho-aluminate, calcium ferro-aluminate and dicalcium silicate; and calcium fluo-aluminate cement, whose principal hydraulic minerals are calcium fluo-aluminate and dicalcium silicate.

3 Naming principles

3.1 Cement is named by category, according to its principal hydraulic mineral, its mineral addition, its use and its principal characteristic.

3.2 General purpose cement is named after the silicate mineral of the cement and may carry in front of that name the name of a mineral addition or another suitable name, for example portland cement, ordinary portland cement, portland-slag cement.

3.3 Special cement is named after its principal mineral, its characteristic or its use, and may carry in front of that name a type designation or the name of a mineral addition, for example calcium aluminate cement, calcium sulpho-aluminate cement, rapid hardening portland cement, low heat portland-slag cement, class G oil well cement.

4 Terms for cement products

4.1 cement: finely ground material which, mixed with water to form a plastic paste, can hydrate and harden in air and can go on hardening in water while keeping its strength and volume stability; an inorganic hydraulic binding material.

4.2 portland cement: hydraulic binding material made by finely grinding portland cement clinker with a suitable amount of gypsum, in which 0 % to 5 % of mineral addition is allowed.

4.3 ordinary portland cement: hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker together with mineral addition not exceeding 20 % of the total mass of the cement as the principal components.

4.4 portland-slag cement: hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker and granulated blast furnace slag as the principal components.

4.5 portland-pozzolana cement: hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker and pozzolanic mineral addition as the principal components.

4.6 portland-fly ash cement: hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker and fly ash as the principal components.

4.7 portland-composite cement: hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker and two or more mineral additions as the principal components.

4.8 portland-phosphorous slag cement: hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker and granulated electric furnace phosphorous slag as the principal components.

4.9 portland-mangnesium slag cement (English term as printed in the document): hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker and magnesium slag as the principal components.

4.10 portland-limestone cement: hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker and limestone as the principal components.

4.11 portland-steel slag cement: hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker, converter or electric furnace steel slag and granulated blast furnace slag as the principal components.

4.12 portland cement for road: hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker whose tricalcium aluminate content does not exceed 5.0 % and whose tetracalcium alumino-ferrite content is not lower than 16.0 %, together with a small amount of mineral addition, as the principal components.

4.13 portland-steel slag cement for road: hydraulic binding material made by finely grinding, with a suitable amount of gypsum, portland cement clinker whose tricalcium aluminate content does not exceed 5.0 % and whose tetracalcium alumino-ferrite content is not lower than 16.0 %, together with converter or electric furnace steel slag and granulated blast furnace slag, as the principal components.

4.14 masonry cement: hydraulic binding material made by finely grinding mineral addition as the principal component with a suitable amount of portland cement clinker and gypsum.

4.15 oil well cement: hydraulic binding material with well cementing properties, made by finely grinding portland cement clinker of suitable composition as the principal component with a suitable amount of gypsum.

4.16 sulphate resisting portland cement: hydraulic binding material with a relatively high resistance to sulphate attack, made by finely grinding portland cement clinker of suitable composition as the principal component with a suitable amount of gypsum.

4.17 white portland cement: hydraulic binding material of a certain whiteness, made by finely grinding, with a suitable amount of mineral addition and gypsum, portland cement clinker obtained by burning raw meal of suitable composition to partial fusion, the clinker being rich in calcium silicate and low in iron oxide.

4.18 coloured portland cement: hydraulic binding material made by finely grinding white portland cement clinker as the principal component with a suitable amount of gypsum and pigment; or made by adding a small amount of colouring agent to the raw meal, burning it to coloured clinker and then grinding that clinker finely with a suitable amount of gypsum.

4.19 moderate heat/low heat portland cement: hydraulic binding material with a moderate or relatively low heat of hydration, made by finely grinding portland cement clinker of relatively low tricalcium aluminate content as the principal component with a suitable amount of gypsum.

4.20 calcium aluminate cement: hydraulic binding material made by finely grinding calcium aluminate cement clinker as the principal component.

4.21 calcium sulpho-aluminate cement: hydraulic binding material made by finely grinding calcium sulpho-aluminate cement clinker as the principal component, with or without a suitable amount of gypsum and mineral addition.

4.22 calcium ferro-aluminate cement: hydraulic binding material made by finely grinding calcium ferro-aluminate cement clinker as the principal component, without or with a suitable amount of gypsum and mineral addition.

5 Terms relating to the properties and test methods of cement

5.1 portland cement clinker: product consisting mainly of calcium silicate, obtained by proportioning calcareous and siliceous materials as the principal raw materials into raw meal, burning it to partial fusion and cooling it.

5.2 calcium aluminate cement clinker: product consisting mainly of calcium aluminate, obtained by proportioning calcareous and aluminous materials as the principal raw materials into raw meal, burning it to complete or partial fusion and cooling it.

5.3 calcium sulpho-aluminate cement clinker: product consisting mainly of anhydrous calcium sulpho-aluminate and dicalcium silicate, obtained by proportioning aluminous and calcareous materials and gypsum as the principal raw materials into raw meal, burning it to partial fusion and cooling it.

5.4 calcium ferro-aluminate cement clinker: product consisting mainly of anhydrous calcium sulpho-aluminate, calcium ferro-aluminate and dicalcium silicate, obtained by proportioning aluminous and calcareous materials and gypsum as the principal raw materials into raw meal, burning it to partial fusion and cooling it.

5.5 calcium fluo-aluminate cement clinker: product consisting mainly of calcium fluo-aluminate and calcium silicate, obtained by proportioning calcareous and aluminous materials and a small amount of fluorite as the principal raw materials into raw meal, burning it to complete or partial fusion and cooling it.

5.6 hydraulicity: property whereby a material ground to a fine powder and mixed with water into a paste forms stable compounds and can harden in moist air and in water.

5.7 pozzolanicity: property whereby a material ground to a fine powder has no hydraulicity on its own but, mixed with lime and water at ordinary temperature, forms products having hydraulicity.

5.8 mineral addition: mineral material added during the grinding of cement. According to its pozzolanicity or latent hydraulicity it is divided into active addition and inactive addition. Mineral additions in common use are granulated blast furnace slag, fly ash and pozzolanic mineral addition.

5.9 active addition: addition usually expressed by the activity index, that is the ratio of the 28 day compressive strength of the test cement to that of the reference cement; an addition whose activity index meets the requirement of the corresponding standard is an active addition.

5.10 inactive addition: addition usually expressed by the activity index, that is the ratio of the 28 day compressive strength of the test cement to that of the reference cement; an addition whose activity index is below the requirement of the corresponding standard is an inactive addition.

5.11 calcium sulphate: material whose principal component is calcium sulphate and which has the property of regulating the setting time and other properties of cement.

5.12 grinding aids: admixture added during the grinding of cement which assists grinding without harming the properties of the cement and of concrete.

5.13 fineness: degree of coarseness or fineness of a powdered material.

5.14 particle size distribution: cumulative distribution of the particles of different sizes in a powdered material.

5.15 cement paste: plastic or hardened material obtained by mixing cement and water.

5.16 normal consistency of cement paste: degree of plasticity of cement paste reaching a uniformly prescribed value when tested by the prescribed method.

5.17 water requirement for normal consistency of cement paste: amount of water needed to prepare cement paste of normal consistency.

5.18 setting time: time from the beginning of mixing with water until cement paste of normal consistency loses its plasticity or reaches the hardened state.

5.19 false setting: phenomenon whereby cement paste or cement mortar loses its fluidity rapidly after mixing with water, but on being remixed without further water recovers its plasticity, the development of strength being unaffected.

5.20 flash setting: phenomenon whereby cement paste or cement mortar loses its fluidity rapidly after mixing with water and hardens, giving off a large amount of heat, and on being remixed without further water does not recover its plasticity.

5.21 soundness: deformation of the hardened cement paste caused by uneven volume expansion.

5.22 standard sand: legal reference material used for testing the strength, the fluidity and other properties of cement mortar, made from natural quartz sand of high purity by screening and washing.

5.23 water-cement ratio: mass ratio of the mixing water to the cement in cement paste and mortar.

5.24 cement mortar: material made by mixing cement, standard sand and water in a certain proportion.

5.25 fluidity of cement mortar: indicator expressing the flow properties of cement mortar.

5.26 water demand of cement mortar: amount of water needed to bring cement mortar to a given fluidity.

5.27 strength of cement mortar: indicator expressing the mechanical properties of cement.

5.28 strength grade of cement: parameter expressing the mechanical properties of cement, the corresponding grade being fixed by the flexural strength and the compressive strength of the cement mortar at the prescribed age.

5.29 curing: process of keeping cement specimens in an environment of prescribed temperature and humidity.

5.30 age: curing time from the mixing of the cement with water until the property is measured.

5.31 dry shrinkage: volume contraction of cement caused by the evaporation and loss of the water in the capillary pores and the gel pores.

5.32 expansion: increase in volume occurring after the cement has hardened.

5.33 water retention: ability of cement paste to retain its water.

5.34 impermeability: ability of hardened cement to resist penetration under liquid pressure after its capillary pores have absorbed water or been saturated with oil.

5.35 frost resistance: ability of cement to resist destruction by freeze-thaw cycles.

5.36 carbonation resistnace (English term as printed in the document): ability of cement to resist attack by the carbon dioxide in the atmosphere.

5.37 wear resistance: ability of cement to resist abrasion by external force.

5.38 sulfate resistance: ability of cement to resist sulphate attack.

5.39 chlorid diffusion coefficient for cement (English term as printed in the document): indicator of the ability of cement to resist the penetration of chloride ions.

5.40 hydration heat: heat given off by the chemical reaction after cement is mixed with water.

5.41 coefficient of chemical resistance: indicator of the ability of cement to resist chemical corrosion.

5.42 alkali content: content usually expressed by the amounts of potassium oxide and sodium oxide; the document gives a formula in which the alkali content reckoned as sodium oxide equivalent is the sodium oxide content plus 0.658 times the potassium oxide content.

5.43 stiffening time: time taken by oil well cement slurry to reach the prescribed consistency.

5.44 free fluid: colourless or coloured liquid separating out of oil well cement slurry when it is at rest.

Relationship to previous standards

The cover and the foreword state that this edition replaces GB/T 4131-1997, Nomenclature, definitions and terminology of cement. The foreword also records the earlier editions of the replaced standard: GB 4131-1984, GB 5947-1986 and GB/T 4131-1997.

The foreword lists the principal changes with respect to GB/T 4131-1997: the title of the standard was changed; special purpose cement and cement of special characteristics were merged into special cement; the category of cement whose principal component is a pozzolanic or latently hydraulic material or another active material was removed; the classification of cement by the principal technical characteristic marked in its name was removed; portland-phosphorous slag cement, portland-mangnesium slag cement, portland-limestone cement, portland-steel slag cement, portland-steel slag cement for road, coloured portland cement, calcium aluminate cement, calcium sulpho-aluminate cement and calcium ferro-aluminate cement were added; a set of property terms including cement paste, false setting, flash setting, dry shrinkage, water retention, impermeability, frost resistance, carbonation resistance, wear resistance, sulfate resistance, chloride diffusion coefficient for cement, alkali content, stiffening time and free fluid was added; the term cement mark was changed to strength grade of cement; and Chinese and English indexes were added.

Note on the printed English terms

Three of the English terms are printed with a typographical error in the document itself and are reproduced above exactly as they appear on the page: 4.9 gives portland-mangnesium slag cement, 5.36 gives carbonation resistnace and 5.39 gives chlorid diffusion coefficient for cement. The Chinese terms that head those three entries are unambiguous, and the intended English readings are magnesium, resistance and chloride respectively.