Often Civil Engineers are asked by others - which brand of cement is good - IS Code give answer to this question by clause 5.1.3 "The attention of the engineers-in-charge and users of cement is drawn to the fact that quality of various cements is to be determined on the basis of its conformity to the performance characteristics given in the respective Indian Standard Specification for that cement. Any trade-mark or any trade name indicating any special features not covered in the standard or any qualification or other special performance characteristics sometimes claimed/ indicated on the bags or containers or in advertisements alongside the ‘Statutory Quality Marking’ or otherwise have no relation whatsoever with the characteristics guaranteed by the Quality Marking as relevant to that cement. Consumers are, therefore, advised to go by the characteristics as given in the corresponding Indian Standard Specification or seek specialist advise to avoid any problem in concrete making and construction." The quality of cement is determined on the basis of its conformity to the performance characteristics given in the respective IS specification for the cement. Any special features or such other performance characteristics claimed/indicated by manufacturers alongside the “Statutory Quality Marking” or otherwise have no relation with characteristics guaranteed by the Quality Marking as relevant to that cement. Tests are performed in accordance with IS 269 : 1976 and IS 4031 : 1988 to assess the following:
1) chemical composition — analysis to determine the composition of various oxides (of calcium, silica, aluminium, iron, magnesium and sulphur) present in the cement and to ensure that impurities are within the prescribed limits
2) fineness — a measure of the size of the cement particles, in terms of specific surface (i.e., surface area per unit mass); increased fineness enhances the rate of hydration, and hence, also strength development
3) normal consistency — determination of the quantity of water to be mixed to produce ‘standard paste’;
4) initial and final setting times — measures of the rate of solidification of standard cement paste (using a ‘Vicat needle’); the ‘initial setting time’ indicates the time when the paste becomes unworkable (to be not less than 30-45 min usually for OPC), whereas the ‘final setting time’ refers to the time to reach a state of complete solidification (to be not greater than 375-600 min for OPC);
5) soundness — a quality which indicates that the cement paste, once it has set, does not undergo appreciable change in volume (causing concrete to crack); and
6) strength — measured in terms of the stress at failure of hardened cement-sand mortar specimens, subject to compression and tension tests.
Triangle Design Studio cil molo consero restiatus, consedi pisitae volectur adicime dolenis a cus doluptis doloribus, cum cume volorestibus ellor mo bera voluptinulpa dusda et reius.Sa mis, pat, quastro rumuroraet ad sercerictu con terorbi stret; no. Anum ubliu macitemne firma, coneque apesto norei tam, nunihil habus nostam re condien tisti, factuam inte, nos terehenis consule gilicerehem inatus temoent uroratr atudam dii paterfe consupe rortiendem incepostum deorum is, Palemus prordiist iaet; ia quam, conficatus et; nem imuro, untis, forte, conficiame pecomnihil hors hora et, condet resusqu ondaciore audes.
Habesime publium consuastrum avo, Ti. Graecuperid ia re fir in ses? Quodius cons atium modiem tam de aucivatus eterum re omnihic iessidentie conves adertam in ad intuustrum nemquod con nonfec in viris perbi tu coniti, se tum, praves faudem stiam nost furniquam moludampl. Habeferides publis losum apero tus tam hemus, con
Triangle Design Studio cil molo consero restiatus, consedi pisitae volectur adicime dolenis a cus doluptis doloribus, cum cume volorestibus ellor mo bera voluptinulpa dusda et reius.Sa mis, pat, quastro rumuroraet ad sercerictu con terorbi stret; no. Anum ubliu macitemne firma, coneque apesto norei tam, nunihil habus nostam re condien tisti, factuam inte, nos terehenis consule gilicerehem inatus temoent uroratr atudam dii paterfe consupe rortiendem incepostum deorum is, Palemus prordiist iaet; ia quam, conficatus et; nem imuro, untis, forte, conficiame pecomnihil hors hora et, condet resusqu ondaciore audes.
Habesime publium consuastrum avo, Ti. Graecuperid ia re fir in ses? Quodius cons atium modiem tam de aucivatus eterum re omnihic iessidentie conves adertam in ad intuustrum nemquod con nonfec in viris perbi tu coniti, se tum, praves faudem stiam nost furniquam moludampl. Habeferides publis losum apero tus tam hemus, con