BS 12:1991 download free.Specification for Portland cement.
1 Scope
BS 12 specifies reqi uremenis for Siti fl and filth manufact LIP of Portland cement and for the strength, physical and cheni PPert les of Pt rt.laflI cement 1S ‘charactenstic values. Requirements for marking, pro VISIOfl of infonnat ion, sainjling an tt’simg for acceptant leliVery and for sevial lwt hlfl mCflt4S are al specified. It. specifies the 1)roILIres for the manufacturer’s aut. ct ntrnl system to ensure conformity and for the purchaser’s assessment omlliaflce at khvvry. This st anlard specifies requirements for VlflQtt. as commonly used in Western Europe I
Nnt. The titles f the ii1 1 jrl ii ‘ns ri ‘Ii m’d t  in t his star an’ lISl’d Ofl 111’ flSilC hak over.
2 Iefinitions
For the purposes of BS 12 the lefiflitiOflS in 115  1N : Seiion 6. 1 apply toget with the lollowing.
2.1 characteristic value
That value of a pmlH’rtY corresonding to an aceeptalle per thntage of IC et.S, generally If hut 5 % for the lower si rengtli limits.
obtained through continuous mass production IWOCSSCS, in particular grinding an1 homogenization processes.
NOTE 3. Qualified and skilled personnel and the facilities to test, evaluate and adjust prodUct quality are escntiaI for producing cement complying with BS 12.
During the cement manufacturing process and its control, the composition of the cement shall be kept within the limits specified in this British Standard.
4 Constituents
4.1 Portland cement clinker Ekrtland cement clinker is a hydraulic material
which shall consist of not less than two-thirds by mass of calcium silicates CaO SiO, and CaO2.Si02, the remainder containing aluminium oxide Al2O, iron oxide Fe20 and other oxides. The ratio by mass CaOSi02 shall be not less than 2.0. The content of magnesium oxide MgO shall not excce 5.0 % (m/in).
I)rtlan(I cement clinker shall be made by burning, at. least to sintermg, a precisely specified mixture of raw materials raw meal, paste or slurry containing CaO, SiO2, A120:1 and small quantities of other materials. The raw meal, paste or slurry shall be finely divided, intimately mixed and therefore homogeneous.
4.2 Minor additional constituents Minor additional constituents if present shall he one or more of granulated blastfurnacc slag, natural pozzolana, pulverized-fuel ash (fly ash) or filler.
7 Physical properties
7. 1 Initial setting time
The initial setting time, determined in accordance with EN 196: Part 3, shall be not less than 60 mm for the 32.5N, 32.5R, 42.5N and 42.5k strength classes nor less than 45 mAn for the 52.5N and 62.5N strength classes.
7.2 Soundness
The expansion, letermineti in accordance with
KN 196 : Part 3, shall he not more than 10 mm.
8 Chemical properties
111 ProPerties shall comply Wit Ii table 2 when teste in accordance wit It the tests relerred to in  of table 2. The roMrtIes for pigmented Ioii land emnt shall IN LS sJweifie in clause 13.
9 Marking
Portlafll eflWIlt shall iN’ Efldrket on the hag or the
leliVery note, and on aity i’rtifwate, with the
lollowiiig particulars:
(a) the name, trade itiark or c t her iii’ans of identification of the mainifacturer to facilitate traceabihty to the works in which the cement was manufactured;
(b) the naitie and sirengi Ii class of the material,
e.g. Portland cement, dass 12. R;
(e) the nuinbir and date of BS 12,
i.e. 115 12 : l91l
10 Information to be provided
10. 1 lk’st certificate
If a tv’st certificate is reqlwsted, it shall itWlII results of the following tt’SIS i n samples of the cement relating to the material delivered:
(a) compressive strength at II her 2 days or 7 days as appn’priate, and also at 28 days, obtained 1mm tests on iuortar pnsms2 in aceordane with EN 19: PaTI I see clause 6;
11 Sampling and testing for acceptance inspection at delivery
11.1 For assessing compliance at delivery, when requested a spot sample of the cement shall be taken in accordance with 3.6 and 6.2, 6.3, 6.4 or 6.5 of EN 196: Part 7: 1989 either before, or at the time of, delivery. A laboratory sample shall be prepared and packed in accordance with clauses 8 and 9 of EN 196: Part 7: 1989. A sampling report shall be completed at the time of sampling and shall be attached to the laboratory sample in accordance with clause 10 of EN 196: Part 7:
1989.
NJrE. lsting may be delayed for up to 5 weeks from the time of sampling provided that there Is confirmation that the sample has been stored continuously as desentwd in 9.2 of EN 196:
Part 7: 1989.
11.2 When the cement is tested for strength (see clause 6), unless otherwise agreed between the purchaser and the manufacturer the pit or quarry from which the CEN Standard sand is obtained and the compaction procedure to be used shall be those in use by the manufacturer at the time when the cement was originally tested.
11.3 When the cement is tested for chemical properties (see clause 8) the sample shall be prepared by the method described in clause 6 of EN196:Part2: 1987.
11.4 The limiting values applicable to acceptance inspection shall be those given in table 3.
NOTE. These values are, in general, based on the ‘major defects’, defined in appendix A which, however, does not contain values of deviation for strength upper limit, loss on ignition and Insoluble residue.
12 Special Portland cements
12.1 Controlled fineness Portland cement Controlled fineness I-krtland cement shall comply with BS 12 and, in addition, its fineness shall lie within a range to be agreed between the manufacturer and the purchaser.
NOTE. Fbr many years there had been a demand by specialist users for a cement which makes it easier to remove excess water from the concrete during compaction. In some applacations the’ fineness of the cement is more critical than Its compressive strength; as a result controlled fineness IkniIand cement was introduced into uS 12: 1989, defined as a Thirtland cement having a specific surface controlled within a small agreed range that u.sually lies below that for ordinary lkrtland cement’. This range has to be agreed between the manufacturer and the purchaser
12.2 Pigmented Portland cement
Pigmented Ikrtland cement shall comply with BS 12 provided that:
(a) the pigments comply with BS 1014;
(b) the chemical composition of the lkrtland cement constituent, excluding pigment, complies with clause 8 of BS 12;
(c) the cement as a whole, including pigment, compiles with this British Standard with the exception of clause 8.
NOTE. The quantity of pigmented cement used m a concrete or mortar mix may need to be greater than that of an unpigmented cement to take account of the amount of pigment present.
13 Conformity criteria cement
manufacturer’s autocontrol
The conformity criteria for continuous inspection shall be taken from appendix A.