pakistan cement standar ps%20232-1983%20(rev)

8/8/2019 PAKISTAN CEMENT STANDAR PS%20232-1983%20(Rev)

1/64

PS:

232-1983 (R)

PAKISTAN STANDARD

SPECIFICATION FOR

PORTLAND CEMENT(ORDINARY, HIGH STRENGTH AND RAPID HARDENING)

____________________________________________________________________________

Pakistan Standards & Quality Control Authority (PSQCA)

Standards Development Centre (SDC/PSQCA)

39-Garden Road, Saddar, Karachi-74400, Pakistan.


2/64

PS:232 1983 (R)

PAKISTAN STANDARD SPECIFICATION

FOR

PORTLAND CEMENT

(ORDINARY, HIGH STRENGTH AND RAPID HARDENING)

0. FOREWORD

0.1 This Pakistan Standard has been revised by the authority of the General Council of

Pakistan Standards Institution after the draft prepared by the Sectional Committee for

Clay Bricks, Cements, Cement Blocks and Hollow Blocks had been approved andendorsed by the Building Materials Divisional Council on 28

thDecember, 1983 in order

to bring it into line with present practice followed in the production and testing of

Cement.

0.2 Detailed test methods described in the appendices to PS: 232 : 1962 have been revised

and also various details of the concrete cube strength test, introduced in PS:232-1962,

have been made more stringent in order to produce more consistent results.

0.3 Specified minima for compressive strength for ordinary High strength and rapid

hardening Portland Cement are now given at ages of 3,7 and 28 days. The 3 and 7 daysstrengths represent substantial increases over the values in the previous edition. The

introduction of a 28 days strength requirement is considered to provide a betterindication of Cement quality than the 7 days strength.

0.4 The optional requirement for the 1-day tensile strength of rapid hardening PortlandCement has been omitted since experience has shown that this test produces rather

variable results and is very invoked.

0.5 The clause 13 on delivery has been omitted as being a contractual arrangement but a

requirement for marking has been introduced.

0.6 The specific surface test is a better method of testing fineness of the cement. Thismeasures the surface area of the particles per unit mass. Sieve test for determining the

fineness has been omitted.

0.7 In preparing this Pakistan Standard the views and suggestions of all the interests have

been taken into full consideration in addition to the following Standard Specification,

the use of which is acknowledged with thanks.

0.8 This standard is Pakistan intended chiefly to cover the technical provision relating to

the testing etc. of the material and it does not include all the necessary provisions of acontract.


3/64

PS:232 1983 (R)

( 2 )

1. BS:12:1978 Ordinary and rapid-hardening Portland Cement.

2. BS:4550-1978 Method of testing cement.

3. BS:4627-1970 Glossary of terms relating to types of cement, theirproperties and components.4. PS:746-1969 Definition and Terminology of Cement.5. PS:747-1969 Chemical Analysis of Cement-Determination of Sulphur

as Sulphide.

6. PS:748-1969 Chemical Analysis of Cement-Main Constivents ofPortland Cement.

7. PS:749-1969 Chemical Analysis of Cements-Determination oftitanium, phosphorus, manganess and of free lime.

8. BS:812 Methods for sampling and testing of mineral aggregates,sands and filters.

9. BS:1881/4/70 Methods of testing concrete for strength.10. BS:1610-1964 Methods for the load verification of testing machines.11. ISO/R-147- 1960 Load calibration of testing machine for tensile testing of

steel.

12. ISO/R-376-1964 Calibration of static proving devices.13. ISO:1920-1976 Concrete tests-Dimension, tolerance and applicability of

test specimen.

14. PS:424-1964 Load calibration of testing machines for tensile Testing ofSteel.

1. SCOPE

1.1 This Pakistan Standard specifies requirements for the composition, the manufacture,

sampling, testing methods and the chemical and physical properties of ordinary and rapid-hardening Portland Cement.

Note: The term rapid-hardening has been adopted in this standard because its use hasbeen accepted in Pakistan. It is synonymous with the designation high early strength which

is used in other countries and should not be confused with Quick-setting cements which are

not covered by this standard.

2. Composition and manufacture of Portland Cement

2.1 The cement, whether ordinary or rapid-hardening, shall be obtained by pulverizingclinker, consisting mostly of calcium silicates, obtained by heating to partial fusion a

predetermined and homogeneous mixture of materials containing principally lime (CaO) and

silica (Sio

2) with a smaller proportion of alumina (A12O3) and iron oxide (Fe2O3).


4/64

PS:232 1983 (R)

( 3 )

2.2 The cement shall contain no additions except as provided for below :

a) Water or gypsum or anhydrite, or other derivatives of calcium sulphate, or any

combination of these substances; the amount of addition to be such that the

limits shown for sulphuric anhydride and loss on ignition shall not be exceeded.

b) Metallic iron from the grinding process shall not be regarded as an addition.

2.3 However, coloured Portland Cements shall be deemed to comply with the requirements

of this Pakistan Standard provided that:

a) The pigments comply with the requirements of BS:1014: (Relevant Pakistanstandard is under preparation);

b) The chemical composition of the Portland Cement constituent complies with

clause 5 of this Pakistan Standard;

c) The cement as a whole complies with the requirements of this Pakistan Standardwith the exception of clause 5.

3. TESTS

3.1 The sample or samples, taken as described in clause 11, shall be tested in the manner

specified for:

a) fineness (clause 4)b)

chemical composition (clause 5)c) compressive strength (clause 6)

d) setting time (clause 7)e) soundness (clause 8)

4. FINENESS

4.1 The cement shall be tested for fineness by the method described in Appendix A and

shall have a specific surface of not less than:

Ordinary Portland Cement 225m2/kg (2250 cm

2/g) Rapid Hardening Portland Cement

325 m

2

/Kg (3250 cm

2

/g)

5. CHEMICAL COMPOSITION

5.1 The chemical composition of the cement shall comply with the following requirements.

5.1.1 Lime saturation factor (LSF). The lime saturation factor shall be not greater than 1.02

end not less than 0.66 when calculated by the formula:

L.S.F =(CaO) 0.7 (SO3)2.8 (Si02) + 1.2 (A1203) + 0.65 (Fe203)


5/64

PS:232 1983 (R)

( 4 )

Where each symbol in parentheses refers to the percentage (by mass of total cement) ofthe oxide, as determined by the methods described in Appendix B-1 for Si03, B-2 for Ca0, B-3

for AI203, B-4 for Fe203 and B-5 for S03 of this Pakistan Standard, excluding any contained in

the insoluble residue referred to in 5.2.

5.2 Insoluble residue

The mass of insoluble residue, as determined by the method described in Appendix C

of this Standard, shall not exceed 1.5%.

5.3 Magnesia

The mass of magnesia, as determined by the method described in Appendix D, shall not

exceed 4.0%.

5.4 Sulphuric anhydride

The mass of total sulphur expressed as SO3 and determined by the method described in

Appendix E, shall not exceed the appropriate value in table 1.

TABLE 1, MAXIMUM TOTAL SULPHUR EXPRESSED AS SO3 (%)

CementWhen tricalcium aluminate is 5% or

less

When tricalcium aluminate is

more than 5%

OPC 2.5 3.0

HSPC 2.5 3.0

RHPC 3.0 3.5

The tricalcium aluminate content (C3A) is calculated by the formula : C3A = 2.65(A1203) 1.69 (Fe203)

Where

C = Ca0

A = A1203

Where each symbol in parentheses refers to the percentage (by mass of total cement) of

the oxide, as determined by the method described in Appendix B-3 for A1 203 and B-4 forFe203, excluding any A1203 contained in the insoluble residue referred to in clause 5.2.


6/64

PS:232 1983 (R)

( 5 )

5.5 Loss on ignition

The loss on ignition, as determined by method described in Appendix F, shall not

exceed 3.0% for cement in temperate climates or 4.0% for cement in tropical climates.

6. COMPRESSIVE STRENGTH

6.1 General. The cement shall be tested for compressive strength by one of the

methods specified in 6.2 and 6.3. The method of test shall be agreed between the vendor* and

the purchaser at the time of placing the order. In the event of a dispute, a retest shall be carriedout in the presence of representatives of the two parties concerned.

6.2 Average compressive strength of three mortar cubes, prepared, stored and tested as

described in Appendix H shall be:

i. Ordinary Portland Cement:

at 3 days (72 1 h) Not less than 15.0 N/mm2

(2200 PSI or 155.0 kg/cm2)

at 7 days (1682 h) Higher than the compressive strength at 3 days and not less than23.5 N/mm

2(3400 PSI or 239.0 kg/cm

2)

at 28 days Higher than the compressive strength at 7 days and not less than

34.5 N/mm2(5000 PSI or 352.0 kg/cm

2).

ii. High Strength Portland Cement :


(3336 PSI or 234.0 kg/cm2)

at 7 days (1682 h) Higher than the compressive strength at 3 days and not less than

32.5 N/mm2

(4690 PSI or 330.0 kg/cm2)


41 N/mm2

(5950 PSI or 418.0 kg/cm2)

iii. Rapid Hardening Portland Cement:

at 3 days (72 1 h) Not less than 29 N/mm2

(4205 PSI or 296.0 kg/cm2)


2(5220 PSI or 367 Kg/cm

2)

at 28 days Higher than the compressive strength at 7 days and not less than46 N/mm

2(6670 PSI or 469.0 kg/cm

2)

6.3 Average compressive strength of three concrete cubes, prepared, stored and tested as

described in Appendix G shall be:


7/64

PS:232 1983 (R)

( 6 )

i. Ordinary Portland Cement:


(91200 PSI or 84.0 kg/cm2)


2(2800 PSI or 197.0 kg/cm

2)


19.0 N/mm2

(2800 PSI or 197.0 kg/cm2)

ii. High Strength Portland Cement :

at 3 days (72 1h) Not less than 13.0 N/mm2

(1885 PSI or 132.5 kg/cm2)


2(2610 PSI or 184.0 kg/cm

2)

at 28 days Higher than the compressive strength at 7 days and not less than29.0 N/mm

2(4200 PSI or 296.0 kg/cm

2)

iii. Rapid Hardening Portland Cement:

at 3 days (72 1h) Not less than 18.0 N/mm2

(2610 PSI or 1830 kg/cm2)

at 7 days (1682 h) Higher than the compressive strength at 3 days and not less than

22.0 N/mm2

(3190 PSI or 224.0 kg/cm2)

at 28 days Higher than the compressive strength at 7 days and not less than33.0 N/mm2

(4785 PSI or 336.0 kg/cm2)

7. SETTING TIME

7.1 The setting times of cement paste of standard consistence as determined by the methods

described in Appendix 1 and Appendix J shall be :

initial setting time : not less than 45 min.

final setting time : not more than 10 h

8. SOUNDNESS

8.1 The cement shall not have a expansion of more than 10 mm when tested for soundnessby the method described at Appendix K

8.2 If the cement fails to comply with this requirement, a further test shall be made in themanner described. For this test, another portion of the same sample shall be used after it has

been aerated by being spread out to a depth of 70 mm to 80 mm at a relative humidity of

50% to 80% for a total period of 7 days. The expansion of this aerated sub sample shall not

exceed 5 mm.


8/64

PS:232 1983 (R)

( 7 )

9. MANUFACTURERS CERTIFICATE

The manufacturer shall be satisfied that the cement at the time of its delivery complieswith the requirements of this Pakistan Standard and, if requested, he shall forward a certificate

to this effect to the purchaser or his representative. The certificate shall include the results of

the tests on samples of cement relating to the material delivered. The following testinformation shall be provided :

*The term Vendor in this Standard means the seller of this cement, whether he be the

manufacturer of the cement or not, fineness, compressive strength at 3,7 and 28 days, initialand Final setting times and soundness.

10. INDEPENDENT TESTS

10.1 If the purchase or his representative requires independent test, they shall be carried out

in accordance with this Pakistan Standard on the written instruction of the purchaser or hisrepresentative.

11. SAMPLING

11.1 If a sample is required for independent tests, it shall be taken, at the option of the

purchaser or his representative, before delivery or within 1 week after delivery of the cement,

by the method described in Appendix L. The tests shall be commenced within 4 weeks ofdelivery. If the vendor so desires, he or his representative shall be present at the sampling.

12. FACILITIES FOR SAMPLING AND IDENTIFYING

12.1 When a sample of cement for testing is to be taken on the premises of the vendor, he

shall afford every facility and provide all labour and materials for taking and packing thesample and as far as possible for Subsequently Indentifying the cement sampled.

Note : It is recognized that there may sometimes be difficulty in complying with the last

requirement since it may not be possible to identify a particular consignment of cement after ithas been placed with other cement in a silo on the users site.

13. COMPLIANCE

13.1 Any consignment or part of a consignment which when sampled in accordance with

clause 11 fails to comply with any one or more of the requirements of this standard, shall bedelede deemed not to comply with this Pakistan Standard.


9/64

PS:232 1983 (R)

( 8 )

14. CEMENT IN TROPICAL CLIMATES

14.1 The temperatures specifically mentioned in clause 3 of appendix-1 are applicable to

temperate climates. Cement intended for use in tropical climates may be tested at temperaturesexceeding 21oC. When so tested, cement complying with the requirements hereins specified

for temperate climates shall be deemed to comply with this Pakistan Standard.

15. MARKING

15.1 Ordinary or rapid-hardening Portland Cement manufactured in compliance with thisPakistan Standard shall be marked in relation to the product (e.g. on the bag, the manufactures

certificate, the delivery note or the invoice, etc.) with the following particulars :

a) The name, trade mark or other means of identification of the vendor ;b) The name of the material, i.e., ordinary or rapid-hardening Portland cement ;c) The number and year of this Pakistan Standard, i.e., PS:232 : 1983 ;d) PSI certification mark.*When cement is tested at temperatures above 21

oC the strength and setting time

requirements may be altered by agreement between purchaser and the vendor. It should benoted that an increase in the testing temperature increases the early compressive strength and

reduces the setting time.

A P P E N D I X A

Methods of testing Cement (Fineness test)

1. TEST PRINCIPLE

The fineness of cement is determined by a procedure giving specific surface expressed

as total surface area in square metres per kilogram.

2. APPARATUS

The following apparatus are required.

2.1 Permeability cell. The permeability cell shall consist of a metal cylinder made intwo flanged parts which are bolted together, containing a perforated plate on which is

supported a medium filter-paper 32 mm in diameter. The joint between flangtes is rendered

airtight by means of rubber or other suitable gasket. The permeability cell is provided with a

plunger by means of which the cement sample is formed, as described below, into a cylindricalbed supported by the filter paper.


10/64

PS:232 1983 (R)( 9 )

The essential dimensions are given below :

Internal diameter of upper of cylinder D = 25.000.03 mm or

D = 25.400.03 mm

mm0.05

External diameter of plunger D =

Depth of bed space when plunger is fully inserted 10.000.03+ 0 mm

Depth of recess in lower part of cylinder 1.6 0.3 mm

- 0

Thickness of perforated plate 1.6+0.03 mm

- 0

The perforated plate is a push fit in the recess.

A typical cell is shown in figure 1

2.2 Manometers. The permeability cell shall be connected to a bed manometer and a

flowmeter manometer as shown in figure 2. The arms of the manometer and of the flowmeter

are about 600 mm long. The capillary tube of the flowmeter shall have a bore of not less than0.5 mm and its dimensions shall be such that the flowmeter constant C (as defined in 3.2) is

between 20 X 10-12

and 40 X 10-12

metric units. The liquid in both U-tubes is kerosene

(paraffin oil).

The necessary airflow may be produced by any convenient means, but the air entering

the apparatus shall be dried by passing a through tower pecked with a suitable desiccant, e.g.

silica gel.

Note. While the apparatus described above should be regarded as standard, alternative

forms of air permeability apparatus may also be used provided they have been calibratedagainst the standard apparatus.

2.3 Balance capable of weighing up to at least 10 g. to an accuracy of 0.0005 g.

3. PREPARATION

3.1 Checking of the dimensions of the permeability cell.

Check the dimensions of the cell when the apparatus is received, and after every 50

determinations, by suitable means. The depth of the bed space may be conveniently measured

by using a test piece of hardened steel, of diameter D 0.2 mm and 10.100.03 mm deep tosimulate the cement bed. Place the test piece on the filter-paper in the cell, insert the plunger

and check with a feeler gauge that the gap between the shoulder of the plunger and the top of

the cell is 0.100.03 mm.


11/64

PS:232 1983 (R)

( 10 )

3.2 Determination of the flowmeter constant. Check the flowmeter constant every threemonths. Pass dryair through the flowmeter at a constant rate for a measured time interval.

Collect the issuing air over kerosene and measure its volume. Note the flowmeter reating.

Calcualte the flowmeter constant C as follows :

C =Vn

Th2PL

Where

V is the volume (in ml) of dry air passed

N is the viscosity (in Ns/m

2

) of air at the calibration temperature

T is the time (in s) during which air is collected

h2 is the flowmeter reading (in mm)

PL is the density (in Kg/m3) of the Kerosine at the calibration temperature.

The viscosity of air in N s/m2

at temperatures in the range of 15oC to 25

oC is shown

below multiplied by 106.

Temp.

o

C 15 17 19 21 23 25to 16 to18 to20 to22 to 24

Viscosity 17.8 17.9 18.0 18.1 18.2 18.3

Repeat this process for five flowmeter readings over the range of 250 mm to 550 mm.

Calculate the average value of C and express the result o to the nearest 0.1 X 10-12

metric units.

3.3 Calibration of the apparatus. calculate the value of K for each apparatus as followsand express the result to the

3 1

nearest 10m

K =1.40 A1 CL


12/64

PS:232 1983 (R)

( 11 )

Where

is the porosity, i.e., 0.475 (see clause 4).

A is the area (in mm2) of the cement bed.L is the depth (in mm) of the cement bed.

C is the flowmeter constant.

For apparatus made tot the alternative dimensions specified in 2.1

D = 25.00 mm 25.40 mm

A = 490.9 mm2

506.7 mm2

L = 10.00 mm 10.00 mm

and K = 612 6.12

C C

3.4 Assembling and testing of the apparatus. - Change the filter-paper after every

determination. In reassembling the permeability cell ensure that the two parts are firmly boltedtogether and test the cell and its connections for leakage.

Note. This is best done by disconnecting at the monometer the rubber tube leading

from the lower and of the cell, sealing the tube with a screw clip, applying air pressure until the

monometer shows a difference in level of at least 500 mm and then sealing off the air inlet.The reading of the monometer should not change by more than 0.5 mm in a period of 1 min.

4. PROCEUDRE

Select a mass of cement from table 1 for a 25.00 mm cell or from table 2 for a 25.40

mm cell which, when compacted, will give a porosity of 0.475 at the measured density of the

cement. (The porosity is defined as the ratio of the volume of pore space to the total volume ofthe bed). Weigh the cement to 0.0005 g and brush it into the permeability cell, which is

gently shaken from side to side to level off the surface. If the cement is lumpy it may first be

rubbed gently with a spatula on glazed paper


13/64

(12)

Table 1. Mass of cement (in g) required to form a bed 25.00 mm in diameter and 10.00 mm deep havin

density range 2800 kg/m3

to 3290 kg/m3

Density Kg/m3 0 10 20 30 40 50 602800 7.216 7.247 7.267 7.293 7.319 7.345 7.370

2900 7.474 7.499 7.525 7.551 7.577 7.602 7.628

3000 7.731 7.757 7.783 7.809 7.834 7.860 7.886

3100 7.989 8.015 8.040 8.066 8.092 8.118 8.144

3200 8.242 8.272 8.298 8.324 8.350 8.376 8.401

Table 2.-Mass of cement (in g) required to form a bed 25.40 in diameter and 10.00 mm deep having a porosity

2800 kg/m3

to kg/m3

Density Kg/m3

0 10 20 30 40 50 60

2800 7.449 7.475 7.502 7.528 7.555 7.582 7.608

2900 7.715 7.741 7.768 7.794 7.821 7.848 7.874

3000 7.981 8.007 8.034 8.060 8.087 8.114 8.140

3100 8.247 8.273 8.300 8.326 8.353 8.380 8.406

3200 8.513 8.539 8.566 8.592 8.619 8.646 8.672


14/64


15/64

PS:232 1983 (R)

( 13 )

Compact the contents by allowing the cell to fall four time from a height of about 10

mm on the bench. Next, slowly insert the plunger and push it home so that the shoulder of

the plunger is in contact with the top of the permeability cell. Do not twist the plunger whilein contact with the cement surface but slowly withdraw it with a twisting motion.

If, on inspection, the cement bed is seen to be disturbed, knock the sample out and

repeat the operation with a fresh sample.

Insert the upper bung and slowly turn on the air ; -Nextinsert the lower bung slowly

and carefully in order to avoid forcing air through the cement in the wrong direction. Adjust

the rate of airflow until the flowmeter monometer shows a difference in level of 300 mm to

500 mm. When the levels are constant, indicating that steady conditions have been obtained,take readings of the difference in level h1 of the bed monometer and of the difference in

level h2 of the flowmeter monometer. Repeat these observations at a different airflow \ratewithin the above range.

5. CALCULATION

Calculate the average value of the ratio h1/h2. Calculate the specific surface, Sw, as

follows and express the result to the nearest 5 m2

/ kg.

K h1Sw =

Where

K is the constant of the apparatus determined in accordance with 3.3

e is the density (in Kg/m3) of the cement determined in accordance with

Section 2,2

h1 is the average ratio of the monometer readings determined in accordance

withh2 clause 4.


16/64

PS:232 1983 (R)

( 14 )


17/64

PS:232 1983 (R)

( 15 )


18/64

PS:232 1983 (R)

( 16 )

Appendix B-1

1. METHOD RECOMMENDED FOR DETERMINATION OF SILICA:

1.1 Procedure. Mix thoroughly 1.000 g of the sample and about 1.0 g of ammoniumchloride in a 100 ml beaker, cover the beaker with a watch glass and add catiously 10 ml of

hydrochloric acid, allowing the acid to run down the lip of the covered beaker. After the

chemical action has subsided lift the cover, add one or two drops of nigric acid, stir the

mixture with a glass road, replace the cover and set the beaker on a water bath for 30 min.Filter through a 90 mm rapid filter paper, transferring the jelly like mess of silicic acid to the

filter as completely as possible without dilution and allowing the solution to drain through.

Scrub the beaker with a rubber policeman, rinse the beaker and policeman and wash the

filter two or three times with hot hydrochloric acid ( 1+99 ). Then was the filter with ten ortwelve small portions of hot water, allowing each portion to drain through completely.

Reserve the filtrate and washings.

Transfer the filter paper and residue to a weighed platinum crucible, dry and ignite,

at first slowly until the carbon of the paper is completely consumed without inflaming andfinally at 1200

0C for 30-45 min. Cool in a desiccator to room temperature (this will take

about 15 min.) and weigh the residue as impure silica.

Treat the silica thus obtained, which will contain small amounts of impurities, in thecrucible with 0.5 ml to 1 ml of the water, 2 drops of sulphuric acid and about 10 ml

hydrofluoric acid and avaporate cautiously to dryness. Heat the small residue finally at1200oC for a minute or two, cool and weigh. The difference between this weight and the

weight previously obtained represents the amount of silica. To this amount of silica add the

amount of silica determined in the filtrate as described in clause 1.2. Fuse the residue with

not more than 0.5 g of potassium pyrosulphate. Dissolve the cold melt in 5 ml ofhydrochloric acid (1+4) and add the solution to the reserved filtrate. Dilute the solution in a

volumetric flask to 500 ml. Mix and reserve.

1.2 Determination of silica remaining in solution.

Note. In an acid medium, silica forms a yellow silicomolybdate complex with

ammonium molybdate. The complex is quantitatively converted to molybdemnum blue by 1amino-2-nephtol-4 sulphonic acid. The interference of phosphate is removed by ammonium

citrate.

1.2.1 Special reagents. Prepare special reagents by the following methods.

(1) Ammonium molybdate. Dissolve 10 g of ammonium polybdate in water,

make up to 100 ml and filter. Store in polythene bottle. Do not keep for more than oneweek.

(2) Citric acid. Dissolve 10 g of citricacid, monohydrate, in water and make upto 100 ml.


19/64

PS:232 1983 (R)

( 17 )

(3) Reducing Solution. Weigh 0.15 g of 1-amino-2-naphthol-4-sulphonic acid,

1.4 g of sodium sulphite and 9.0 g of sodium metabisulphite, dissolve in water, make up to100 ml and filter if necessary. Prepare a fresh solution each week unless refrigerator storage

is available.

Note. 0.7 g of sodium sulphite, anhydrous, may be substituted for 1.4 g of sodium

sulphite, hydrated.

(4) Standard silica solutions

Stock solution. Weigh 0.2000 g of freshly ignited Specpure silica or purest quartz

ground in agate into a platinum crucible containing 2.0 g of sodium carbonate, anhydrous.

Mix, cover the crucible and fuse for 15 min. Dissolve the cooled melt in water in apolythenebeaker and make up to 200 ml.

Store in a polythene bottle.

1 ml contains 1 mg Sio2.

Working solution. Pipette 5 ml to stock solution and dilute with water to 250 ml.

Mix and store in a polythene bottle. The solution should be made up fresh each week.

1 ml contains 0.02 mg Sio.2

(5) Copmpensating solution. Dissolve 0.8 g of ammonium chloride and 8 ml ofhydrochloric acid in water and dilute to 100 ml.

1.2.2 Procedure. To prepare a calibration graph, pipette 10 ml of working standardsolution, in 2 ml inerements, into a series of 100 ml volumetric flasks. Add 5.0 ml of

compensating solution to each and dilute to approximately 20 ml. Add 5 ml ammonium

molybdate solution, rinse the necks of the flask, swirl to mix and allow to stand for 5 10

min Add 5 ml of citric acid solution to each flask, rinse, mix and wait 5 min. Add 2 ml ofrducing solution, make up to 100 ml with water and mix. Allow to stand for at least 30 min

before measuring the colour. The colour is stable for at least 24 h.

Prepare a sample solution by diluting the filtrate from the silica separation (1.00 go

of cement, see 1.1) to 500 ml. Pipette 20 ml of this olution into a 100 ml volumetric lfask.

Add 5 ml of ammonium molybdate solution and contain as in preceding paragraph.

1.2.3 Measurement. The colour can be measured by visual comparision orinstrumentally, using an absorptiometer or a spectrophotomer (as 650 mm). The size

of absorption cell will depend on the instrument available.


20/64

PS:232 1983 (R)

( 18 )

Appendix B-2

1. METHOD RECOMMENDED FOR DETERMINATION OF CALCIUM

OXIDE

1.1 Reagents. Prepare reagents by the following methods:

(1) Potassium hydroxide solution. Dissolve 200 g of potassium hydroxide in

one litre of water.

(2) Glycerol solution. Dilute 200 ml of glycerol to one litre with water.

(3) Triethamolamine. Solution. Dilute 200 ml of pure triethanolamine to one

litre with water.

(4) Murexide indicator. Grind together 0.5 g of murexide (ammonium

purpurate colour Inxex 56083) and 100 g of sodium chloride to form a homogeneousmixture.

(5) Diamino-ethane-tetra-acetate solution (EDTA). Dissolve 6.67 g ofdisodium-diamino-ethane-tetra-acetate (EDTA disodium salt) in distilled water, adjust to PH

10 with potassium hydroxide solution and dilute to one litre. Store in a polythene bottle.

1.1.2 Standardization.- To standardize, dissolve about 0.1 g, accurately weighted, of purecalcium carbonate in dilute hydrochloric acid, taking care that no loss of liquid occurs.

Warm to remove carbon dioxide, cool and dilute to about 200 ml with water. Adjust the pHto 12.2-12.5 with potassium hydroxide solution. Add approximately 0.06 g of murexideindicator and titrate with EDTA solution in a photometric end-point detector*. An increase

in optical density occurs as the end-point is approached.

As the end-point is approached make successive, small, equal increments of the

EDTA and note the steady galvanometer reading after each increment. Continue until the

galvanometer is not, or is only slightly, affected by the addition of-DTA.

Plot the galvanometer readings against the volume of EDTA and find the end-point

by the intersection of the line of steepest slope and the line of constant optical density. Use

only those points in the immediate vicinity of the end-point. See example in Fig 1.

If W = weight of CaCO3

And t = ml of RDTA for equivalence,

then 1 ml EDTA = mg CaO.56.08 X 1000 W

100.09 X t


21/64

PS:232 1983 (R)

( 19 )

1.3 Procedure. Commence with a portion of the filtrate and washings obtained by the

procedure specified for total silica in clause 1.1 Appendix B-1.

Take 50 ml aliquots, add 20 ml of glycerol solution and 20 ml of triethanolamine and

adjust to pH 12.2-12.5 with potassium hydroxide, using a pH meter. Add approximately0.06 g of murexide indicator.

Titrate with EDTA (1 ml = 1.0 mg of CaO, i.e. about 6.67g of disodium salt/litre) inthe photo-electric end-point detector.

Record the volume of EDTA added and the galvanometer readings obtained PlotVolume of EDTA against galvanometer-readings, using only those results in the immediate

vicinity at the endpoint, and find the exect end point as in the example.

1.4 Calculation

CaO%=VE

Where V ml = EDTA required for equivalence per 1 g of Cement and

E=Standardization factor of the EDTA solution.

Appendix = B-3

1. METHOD RECOMMENDED FOR DETERMINATION OF ALUMINA:

1.1 Reagents. Prepare reagents by the following methods:

(1) Aluminium Stock solution. 1 mg of A12O3 per ml. Weight 0.2647 g of aluminium

metal (99.99% pure) into a ploy-propylene beaker. Add 30 ml of water and 1 g of sodiumhydroxide. When solution is complete, cool and wash into a 500 ml volumetric flask, add 10

ml of hydrochloric acid, cool, makeup to the mark with water and mix.

(2) Aluminium standard solution. 0.2 mg of A12O3 per ml. Pipette 50 ml of the 1

mg/ml solution into a 250 ml volumetric flask, make up to the mark and mix.

(3) Ammonia (1+1). Add 500 ml of ammonia solution to 500 ml of water and mix.

(4) Ammonium acetate. (40%) Dissolve 200g of ammonium acetate in water and

makeup to 500 ml. Mix and filter.

(5) Ammonium chloride, Solid.

(6) Chloroform. Containing as stabilizer not more than 2% ethanol.


22/64

PS:232 1983 (R)

( 20 )

(7) Cupferron. (6%). Dissolve 3 g solid, which must be pale in colour and as nearlywhite as is available, in 50 ml of water. Add about 1 g of activated charcoal, stir well and

filter. The solution shall be discarded at the first sign of deterioration; the rate of

deterioration can be reduced by storing in a refrigerator. It is also recommended that thesolid reagent should be stored in the cold.

(8) Hydrochloric acid

(9) Hydroxyammonium chloride. Dissolve the required quantity in a little water and

filter, if necessary, before use.

(10) 8-Ihydroxyquinonlium (5%). Dissolve 50 g of 8-quinolinol in 120 ml of glacial

acetic acid, dilute to 1 litre with water and filter.

(11) Methyl red indicator. Dissolve 0.2 g of methyl red in 100 ml of ethanol (95%).

(12) Nitric acid

(13) 1 : 10-Phenanthroline (1%).-Dissolve 0.1 g of 1:10-Phenanthroline hydrate in a

mixture of 5 ml of glaciaf acetic acid and 5 ml of water. A larger quantity may be preparedif required for immediate use.

1.2 Procedure

1.2.1 Comence by using a portion of the filtrate and washings obtained by the procedure

specified for total silica in clause 1.1 of Appendix B-1.

1.2.2 Pipette out exactly 100 ml into a 250 ml borosilicate glass beaker, of any shape

preferred by analyst. Pipette out a further 100 ml similarly. Treat each aliquote as follows.

Bring the solution to the boil. Add ammonia, from a dispensing buretto or other

suitable vessel, until the liquid is just alkaline to methyl red. Do not add any bromine.

Either : Pour through a 90 mm or 110 mm rapid, hardened, ashless filter paperand allow to drain completely. Do not wash. Discard the filtrate, place the original beaker

under the funnel and sissolve the R2O3 precipitate on the paper, using hydrochloric acid ( a

total of just 20 ml) and boiling water alternately. The total volume should not exceed about80 ml, but it is imperative to ensure that the R2O3 is completely redissolved.

or. Preferably : Pour into a centrifuge-tube, without rinsing and spint at about3000 rev/min for 10 min. Pour off the liquid as completely as possible into a clean beaker; it

is very unlikely that any R2O3 will thus be lost but if it is, recover it by filtering the poured

off liquid. Dissolve the R2O3 in the centrifuge tube using 20 ml of hydrochloric acid and

warm water and rinse all back into the original 250 ml beaker ; the total volume should notexceed about 80 ml.


23/64

PS:232 1983 (R)

( 21 )

1.2.3 Cool the solution (of the R2O3 from 0.2 g of cement) to 10oC or lower. Similarly

cool the water, cupferron solution and chloroform to be used.

Transfer the solution to a 250 ml conical seporatingf Funned (with glass stopper and

preferably with polytetrafluorethylene stopcockey) which has been marked at 100 ml. Wash

out the beaker with cool water into the funnel until this mark has been reached. Add 5 ml ofcooled cupferron solution. Add also 10 ml, chloroform Stopper, shake vigorously and

release excess pressure by carefully loosening the glass stopper (not by opening the

stopcock). Rinse the stopper into the funnel. Stand long enough to allow the layers to

separate. Without delay run off the lower (chloroform) layer into a beaker, as completely aspossible without rising loss of the equeous layer.

Add a few drops of cupferron solution to the aqueous layer. Only a white precipitate,

re-dissolving, should be produced. (If a coloured precipitate appears, ad 2.5 ml of cupferronsolution plus 10 ml of chloroform and repeat from above. Add further 10 ml portions of

chloroform and rpeat from above (without adding cupferron) till the chloroform layer iscolourless and the aqueous layer is clear. Discard the chloroform extracts.

1.2.4 Rund and wash the aqueous layer, filtered if necessary, into a 500 ml conical or tall-shape beaker carrying a mark at 200 ml. Heat on the water-bath until any small amount of

chloroform present seems to have been removed, then boil carefully to ensure complete

removal. (To ensure a final precipitate of adequate size in the blank add 50.0 ml of standard

aluminium solution, equivalent to 10.0mg of A12O3. to the blank at this point.)

1.2.5 Adjust volume to about 200 ml. Add the required quantity of 8-hydroxyquinolinesolution : for samples with up to 7.5% A12O3 this will be 10 ml; increase proportionately forhigher percentages. Add slowly, while stirring with a thermo meter, 40 ml of ammonium

ecetate solution. Continue to stir as the liquid is heated to 60-65o

Co

and maintain this

temperature for 10 min. stirring occasionally. If 65oC is exceeded, break down of the iron-

phenanthroline complex any lead to high results for alumina. Allow to cool for 30 min.

1.2.6 Filter through a sintered glass crucible of a porosity approximately equivalent to

Grade No.4 and about 40 ml capacity, which has been weighed after washing with cid anddrying at 140

oC. (It is advisable to check that further acid washing does not alter the weight

of the crucibles used (with a rubber policeman complete the transfer of the precipitate from

the beaker (and from the thermometer). Wash with water at 40-50

o

C, suck dry, transfer thecrucible to an oven, maintain at 140o

C for 2 h, cool for 30 min. in a desiccator and weigh.

Check constancy of weight after a further 30 min. of heating. The precipitate should be

close to mimosa yellow, a greenish precipitate indicates that iron has escaped separation andcomplexing.


24/64

PS:232 1983 (R)

( 22 )

1.2.7 A12O3 = weight of precipitate X 0.1110. Adjust the result according to the difference

between the blank and the A12 O3 that it is known to contain. Calculate the voluesobtained from the aliquots to percentages and report the average percentage of the two, to

the nearest 0.01% as the alumina content of the sample.

11.10 (s-b)

0.2Thus : A12O3% =

Where : s = weight of precipitate from 0.2 g of cement and

b-weight of precipitate from blank 0.090 (0.090 being the weight

in grammes of aluminium oxinate equivalent to 0:010 g of A12O3.

1.2.8 Alternative routine method for tropical elimates for routine work in tropical climatesthe following method of determination of alumina may be used as an alternative, though the

method described above remains the reference method.

Prfoceed as in 1.2.1 and 1.2.2, but instead of 20 ml hydrochloric acid, as in 1.2.2,

substitute the smallest effective quantity then, nearly neutrelize the hot solution (of the R2

O3 from 0.2 g of cement) with sodium hydroxide solution. Bhoil 100 ml of sodiumhydroxide. 10% solution and pour the hot R2O3 solution into it while stirring. Filter off the

precipitated iron and titanium on a hardened repid paper and wash well with warm

sodiumhydroxide 5% solution.

Acidify the filtrate with hydrochloric acid, using a very little methyl red as indicator. Nearly neutralize with ammonia, add exactly 2 ml of hydrochloric acid and boil off anyCO2. Cool to 50

oC, add 1 g of hydroxyammonium chloride (dissolved in a little water) and 5

ml of 1 : 10-phenanthroline solution, stir and maintain near 50oC for 5 min.

Continue as in 1.2.5, 1.2.6 and 1.2.7.

APPENDIX B 4

1. METHOD RECOMMENDED FOR DETERMINATION OF IRON OXIDE

1.1 Reagents

Prepare reagents by the following methods :

(1) Stannous chloride solution. Dissolve 5 g of SnC12.2H2O in 10 ml of hydrochloric

acid and dilute to 100 ml. Add2 pieces of iron-free tin and boil until the solution is clear.

Keep the solution in a dropping bottle containing some metallic tin.


25/64

PS:232 1983 (R)

( 23 )

(2) Barium diphenylamine sulphonate indicator. Dissolve 0.3 g of barium diphe

nyalmine sulphonate in 100 ml of water.

(3) Standard potassium dichromate solution. (1ml=0.004 g Fe2O3). Dissolve 2.457 g ofdried K2Cr2O7

in water and dilute to 1 litre.

(4) Mercuric chloride safurated solution.

1.2 Procedure :

To 1.000 g of sample in a 250 ml conical flask add 40 ml of cold water and while

stirring the mixture vigorously add 10 ml of hydrochloric acid. If necessary, heat the

solution and break up the cement with the flattened tip of a glass rod until it is certain thatall the cement is completely decomposed.

Head the solution to boiling and treat with SnC12 solution, adding this drop by drop

with swirling until the solution becomes colourless. Add one drop in excess and cool thesolution to room temperature. Rinse down the interior of the beaker with water and add, all

at one time, 10 ml of saturated HgC12 solution, Mix vigorously for 1 min and add 10 ml of

H3 PO4 (1+1) and two drops of barium diphenylamine sulphonate indicator, Add sufficientweter so that the volume after titration is between 75 mland 100 ml. Titrate with the

standard K2Cr207 solution. The end-point is taken where one drop causes an intense purplecolour which remains unchanged by further addition of standard K2Cr2 solution.

1.3 CALCULATION

Calculate percentage of Fe203 as fallows:

Fe2O3% = 0.004 V X 100

Where V = ml of K2Cr2O7 solution required by 1 g of cement sample.

APPENDIX-B-5

1. METHOD RECOMMENDED FOR DETERMINATION OF SULPHURIC

ANHYDRIDE

1.1 To 1.000,g of cement in a 250 ml beaker add 25 ml of cold water and while stirringvigorously add 5 ml of hydrochloric acid. If necessary, heat the solution and break-up the

cement with the flattened end of a glass rod until decomposition is complete. Dilute the

solution to 150 ml and heat it just below boiling point for 15 min. Filter on a medium filter paper and wash the residue thoroughly with hot water. Dilute the solution to 250 ml and

boil. Add 10 ml lot hot barium chloride solution (100 g 01) dropwise from a pipette, boil

until the precipitate is properly formed, let the solution stand at Just below boiling point for

at least 30 min and leave to cool for 12-24 h.


26/64

PS:232 1983 (R)

( 24 )

Ensure that the volume of the solution remains between 225 ml and 260 ml addingwater if necessary. Filter the precipitate on a slow filter paper, wash free from chlorides and

place the filter paper and its contents in a weighed platinum or porcelain crucible. Heat

slowly and burn of the filter paper without flaming Ignite at 800oC for 15 min, cool in a

desiccator and weigh the barium sulphate.

Verify that the obtained weight remains constant after a second ignition of 5 min.

1.2 Calculate SO3 content as follows:

SO3% = W X 34.3

Where W = weight of BaSO4 in grammes.

APPENDIX C

1. METHOD RECOMMENDED FOR DETERMINATION OF INSOLUBLE

RESIDUE

1.1 Procedure:

To 1.000 g of sample add 10 ml of cold water and whilst vigorously swirling the

mixture add 5 ml of hydrochloric acid.

If necessary, warm the solution gently and disperse the sample until decomposition

of the cement is complete.

Dilute the solution to 50 ml and digest for 15 min at a temperature just below

boiling. Filter the residue on a medium filter paper, wash six times with hot water and then

transfer the filter paper and its contents back to the reaction beaker.

Add 100 ml (10g/1) of sodium hydroxide, and maintain the solution at a temperature

just below boiling point for 15 min. In the presence of methyl red as indicator acidify the

solution with hydrochloric acid and add an excess amount equivalent to 4 or 5 drops ofhydrochloric acid. Filter on a medium filter paper and wash the residue 12 to 15 times with a

hot solution of ammonium nitrate (20g/1).

Ignite the residue to constant weight in a weighed crucible at 900oC to 1000

oC.


27/64

PS:232 1983 (R)

( 25 )

1.2 Analysis of Insoluble Residue.

If the insoluble residue does not exceed 0.36% assume that it contains 2/3 Sio2 and

1/3 A12O3.

If the insoluble residue exceeds 0.36% fuse it with sodium carbonate plus borax,

take up in waterplus hydrochloric acid and datermine Si, A1, Fe and Ti by colorimetric

procedures as required.

If barium sulphate or other abnormal insolubles are present the analyst should design

a method appropriate for them and indicate it in his report.

APPENDIX-D

1. METHOD RECOMMENDED FOR DETERMINATION OF MAGNESIA

1.1 Reagents, Paper reagents by the following methods.

(1) Triethanclamine solution. As in clause 1.1 Appendix B-2.

(2) Methyl thymol blue complexone indicator. Grind together 0.5 g of methyl thymol

blue complexone and 100 g of potassium nitrate to form a homogeneous mixture.

(3) Diamino-ethane-tetra-acetate solution (EDTA). The solution used in clause 1.1.Appendix B-2 is suitable.

1 ml = E mg CaO = 0.719E mg Mg0.

(4) Ammonium chloride/ammonia buffer (pH 10.0). Dissolve 70g of ammonium

chloride in water, add 570 ml of ammonium hydroxide solution and dilute to 1 litre with

water.

1.2 Procedure : Commence by using a portion of the filtrate and washings obtained

by the procedure specified for total silica in clause 1.1. Appendix B-1.

To a 50 ml aliquot add 20 ml of triethanolamine solution and adjust the pH to 10.0

with ammonium chloride/ammonia buffer. Titrate for the sum of magnesia and calcium with

EDTA solution, using methyl thymolblue complexone indicator and a photometric end-point detector. Find the endpoint in the same way as given in Appendix B-2. Note that as the

end-point is approached the optical density decreases.


28/64

PS:232 1983 (R)

( 26 )

1.3 Calculation

Mgo % = (X-V) + 0.719 E

Where V and E have the values obtained under clause 1.4 Appendix B-2 and X is the

volume of EDTA required in the titration for the sun of magnesium and calcium.

APPENDIX E.

1.1 Method Recommended ror Determination of Total SULPHUR.

1.2 Procedure

To 1.000 of cement add 25 ml of saturated bromine water and while stirring

vigorously and add 5 ml of hydrochloric acid saturated with bromine. If necessary, heat the

solution and break up the cement with the flattened end of a glass rod until decomposition is

complete. Dilute the solution to 150 ml and heat it to boiling point until all the promino hasbeen driven off. Then proceed as in clause 1.1 Appendix B-5.

1.3 Calculation

S% = WX 13.73

where W-weight of barium sulphate in grammes.

APPENDIX F

1. METHOD RECOMMENDED FOR DETERMINATION OF LOSS-ON-

IGNITION

1.2 Procedure. In a weighed covered platinum crucible (20 ml to 25 ml) head 1.000 g

of the sample to constant weight in a muffle furnace at 925 25oC. The initial heating takes

15 min, subsequent period last 5 min.

1.2.1 Expression of results. The percentage loss-on-ignition is calculated to the nearest 0.1

%.

Note. If heating is carried out at a different temperature, this fact should be

mentioned in the analysis report.

1.3 Procedure. Weigh approximately 1 g of the cement sample into a shallow

platinum or silica dish of diameter 25 40 mm and heat for 305 min at a temperature of925 + 25

oC. Allow to cool, covered in a desicator cover magnesium perchlorate. Weigh and

calculate the percentage loss-on-ignition.


29/64

PS:232 1983 (R)

( 27 )

APPENDIX G

METHODS OF TESTING CEMENT

1. COMPRESSIVE STRENGTH OF CONCRETE CUBES

1.1 Test Principle.The strength of cement is determined by compressive strength testson 11 mm concrete cubes, made with specified coarse and fine aggregates, mixed by

machine and compacted manufally with a compacting bar.

Note. The water/cement ratio is 0.60 (C1, table2) for all cements exceptsupersualphated and high alumina, for which values of 0.55 (C2, table2) and 0.45 (C3, table

2) respectively are used.

1.2 Refererence. The titles of the standards publications referred to in this clause ofthis Section are listed on the back cover.

1.3 Apparatus. The following apparatus is required.

1.3.1 Moulds

1.3.1.1 Size. The moulds shall be 100 mm cubes.

1.3.1.2 Constructil. The mould shall be of ferrous metal (preferably cast iron or cast steel)and rigid enough to prevent distortion. The surface hardness of each internal face shall be at

least 95 Rockwell (Scale B) hardness value. It shall be constructed in such a manner that itfacilitates the removal of the moulded, specimen without damage, the parts of the mould,when assembled, shall be positively and rigidly held together by suitable means, both

during the filling and on subsequent handling of the filled mould.

Each mould shall be provided with a steel base plate which shall be rigidly attached

to the mould and shall support it without leakage or distortion.

1.3.1.3 Tolerances. The mould shall be such that, when assembled ready for use, thedimensions and internal faces are accurate within the following limits.

(a) Dimensions. The depth of the mould and the distance between either pair ofopposite internal faces, each based on the average of four symmetrically

placed measurements, shall be 100.00 0.15 mm.

(b) Flatness. The surface of each internal face shall lie between two perallel

planes 0.03 mm apart. The joints between the sections of the mould andbetween the bottom surface of the mould and the top surface of the base plate

shall lie between two parellel planes 0.06 mm apart.


30/64

PS:232 1983 (R)

( 28 )

(c ) Squareness. The surface of each internal face shall lie between two parallel

planes 0.5 mm apart which are perpendicular to the bottom surface of the

mould and also to the adjacent internal faces.

(d) Parallelism. The top surface of the mould shall lie between two parallel

planes 1.0 mm apart, parallel to the bottom surface.

(e) Surface texture. The surface textural of each internal face shall be 3.2

m CLA.

1.3.1.4 Assembly. In assembling the cleaned mould ready for use, the joints between

the sections of the mould and between the bottom of the mould and the base plate shall be

sealed by a thin film of gresse or other suitable method to prevent escape of water. Anyexcess grease shall be carefully removed. The internal faces of the assembled mould shall

be thinly couted with mould oil to prevent adhesion of the concrete.

1.3.3 Trowel. The trowel shall have a cast steel blade, a suitable type is shown infigure 2.

1.3.4 Compacting bar. The compacting bar shall be a steel bar weighting 1.8 Kg andhaving a ramming face 25 mm square.

1.3.5 Tank. The tenk shall contain clean tap water, which shell be renewed at least avery

saven days with water at the specified temperature.

Specimens made with high alumina, supersulphated or Portland-tube cements shalkl

not be placed in the same tank.

1.3.6 Compression testing machine. The compression testing machine shall be of

suitable capacity for the test and shall comply with the requirements described in Appendix-

M.

1.4 Temperature and humidity conditions. The temperature throughout the entire

test procedure shall be controlled about a madpoint of 20oC with permitted variations as

shown in table 1. The minimum relative humidity shall be as given in table 1.

TABLE 1. Temperature and humidity conditions

Situation Permitted

temperaturevariation

Minimum

relative humidity

oC %

Mixing room 2 65

Moist curing chamber 1 90

Water curing tank 1 ---

Compression testing room 2 50


31/64

PS:232 1983 (R)

( 29 )

Note. A record should be kept for reference purposes of the actual temperature and

relative humidity conditions.

Before use, all materials, moulds and other appliances shall be brought to the sametemperature as the air in the mixing room, by storing them in the room for a sufficient time.

1.5 Preparation of speumen. The specimens shall be prepared as follows.

1.5.1 Number of cubes. Make batches of six or nine cubes, three for testing at each of the

specified ages.

1.5.2 Aggregates. The coarse aggregate and the sand shall comply with the requirements

described in Appendix- O and P

If the moisture content of the coarse aggregate, when tested by the standard (oven

drying) method specified in Appendix M, exceeds 0.1% it shall be dried at a temperature

not exceeding 110oC. Sieve the coarse aggregate on 10 mm and 5 mm sieves with square

holes so that it is substantially free from oversized and undersized particles.

1.5.3 Proportioning. The masses of the individual materials for batches of six or ninecubes are given in table 2 and 3.

1.5.4 Mixing. Place the weighed materials in the mixer pan in the following order :

Sand, Cement, Coarse aggregate.

Hold the mixing water ready and start the mixer. After 15 s and the water uniformly

during the next 15 s; then continue mixing for a total time of 180 5 s. After the machinemixing turn the concrete over in the pan a few times with a trowel to remove any slight

segregation. If this is not possible, transfer the concrete to another suitable vessel and turn itover similarly therein.

1.5.5 Compacting. Half fill the cube moulds as quickly as possible. Compact each with

exactly 35 strokes of the compacting bar, uniformly distributed over the cross section of themould. Place a further quantity of concrete in each mould to form the top layer and compact

similarly. The strike off the top of each cube and smooth with the trowel so that the surface

of the concrete is level with the top of the mould. Complete the entire operation within 15min from the completion of the mixing.

MassMix type (see

note to 1.1)

Material Proportions by

mass 6 cubes 9 cubes

C1 Cement

SandCoarse aggregate

Water

1.0

2.53.5

0.60

g

220055500

770010

13205

g

320058000

1120010

19205


32/64

PS:232 1983 (R)

( 30 )

C2 CementSandCoarse

aggregate

Water

1.02.53.5

0.55

220055500

770010

12105

320058000

1120010

17605

C3 Cement

Sand

Coarseaggregate

Water

1.0

1.875

2.6250.45

29405

5500

770010

13205

42705

8000

1120010

19205

TABLE 3. Mass of individual fractions of sand:

Mass

6 cubes 9 cubes

Fraction A(2.36 mm to 1.18 mm)

B(1.18 mm to 600 m)C(600 m to 150 m)D(300 m to 150 m)

E(150 m to 90 m)

g

550516505

14005

8005

g

800524005

20005

12005

1.6 Storage of specimens.-Immediately after preparation place the moulds in a singlelayer on a level surface in the moist curing chamber. In order to reduce evaporation, cover

the exposed top of the cubes with a flat impervious sheet (e.g. of clean thin rubber for

plastics, or lightly oiled steel) making contact with the upper edge of the mould. After

240.5h mark the cubes for later identification and remove from the moulds. Immediately

submerge all specimens, except those to be tested at 24 h, in the tank and arrange them insuch a way that the temperature variation specified in table 1 is not exceeded. Leave the

cubes in the tank until just prior to the test.

Specimens to be tested at 24 h are marked and demoulded 15 min to 20 min before

the test and are covered with a damp cloth so that they remain in the moist condition. If the

concrete has not achieved sufficient strength after 24 h to be handled without fear of

damage, delay the demoulding for a further period of 24 h but state this fact in the testreport.


33/64

PS:232 1983 (R)

( 31 )

1.7 Testing of specimens.- Determine the compressive strength of the cubes, under the

temperature and relative humidity conditions specified in table 1 for the compression testing

room: at the specified age, calculated from the time of adding the water to the other

materials, by the procedure specified in Appendix-M, the auxiliary platens. Test thespecimens within the following limits :

24 0.5 h

3 days (72 1 h)

7 days (168 4 h)

and 28 days (28 days 4 h)

1.8 Calculation. Calculate the average of the individual results of the set of threespecimens tested at the same age, end express the result to the nearest 0.5 N/mm

2. If one

result within the set varies by more than 5% from the everage of the set, discard the result

and recalculate the average of the remaining results. If more than one result varies by morethan 5% from the average, discard the set of results.

1.9 Report. Report the individual results and the average compressive strength to the

nearest 0.5 N/mm2

indicating if any result has been discarded.

APPENDIX H

1. COMPRESSIVE STRENGTH OF MORTAR CUBES

1.1 Test principle. The strength of cement is determined by compressive strength tests

on 70.7 mm mortar cubes, made with a specified sand, mixed by hand and compacted bymeans of standard vibration machine.

1.2 Reference. The titles of the standards publications referred to in this clause ofthis Section are listed on the back cover.

1.3 Apparatus. The following apparatus is required.

1.3.1 Moulds.

1.3.1.1 Size. The moulds shall be 70.7 mm cubes, the area of each face being 5000 mm2.

1.3.1.2 Construction. The mould shall be of metal that is not attached by cement mortar

and rigid enough to prevent distortion. It shall be constructed in such a manner as to

facilitate the removal of the moulded specimen without damage. The parts of the mould,

when assembled, shall be positively and rigidly held together, by suitable means, bothduring the filling and on subsequent handling of the filled mould. Each mould shall be

provided with a steel base plate to support it without leakage. The weight of the mould and

base plate shall be such as to comply with the requirements given in 1.3.3, for the mass ofthe machine.


34/64

PS:232 1983 (R)

( 32 )

1.3.1.3 Tolerances. The mould shall be such that, when assembled ready for use, thedimensions and internal faces are accurate within the following limits :

(a) Dimensions. The depth of the mould and the distance between either pair ofopposite internal faces, each based on the average of four symmetrically

placed measurements, is 70.7 0.1 mm.

(b) Flatness. The surface of each internal face shall lie between two parallel

planes 0.03 mm apart. The Joints between the sections of the mould andbetween the bottom surface of the mould and the top surface of the base shall

lie between two parallel planes 0.06 mm apart.

(c) Squareness. The surface of each internal face shall lie between two parallel planes 0.5 mm apart which are perpendicular to the bottom surface of the

mould and also to the adjacent internal faces.

1.3.2 Trowels. The trowels shall have a cast steel blade, a suitable type is shown in

figure 1.

1.3.3 Vibration machine. The vibration machine shall consist of a table mounted on coil

springs to carry the cube mould, and a revolving shaft provided with an accentric. By means

of a balance weight beneath the base plate attached rigidly to the table, the centre of gravity

of the whole machine, including the cube and mould, shall be rought either to the centre ofthe eccentric shaft or within a distance of 25 mm below it. In consequence of this, the

revoling eccentric imparts an equal circular motion to all parts of the machine and mould,

this motion being equivalent to equal vartical and horizontal simple harmonic vibration 90

o

out of phase. The minimum running speed of the mechine shall be well above its natural

frequency on its supporting springs, so that the amplitude of vibration is supporting springs,

so that the amplitude of vibration is independent of the speed. The motor shall be preferablyof the synchronous type and the drive is by means of an endless belt running on a crowed

pulley on the motor and a crowned pully on the vibrator. The machine shall be provided

with a suitable clamp to bold the assembled mould firmly on the table, and with a suitablehopper to facilitate filling of the mould.

The machine shall be constructed to comply with the following essential

requirements.

Mass of machine on its supporting springs (excluding mass of solid eccentric but

excluding mass of mould, mould clamp, hopper and cube) 29 Kg approx.

Out-of-balance moment of

eccentric shaft 0.016 N m

Normal running speed of eccentric shaft 12000 400 r/min

A typical vibration machine of the type described above is shown in figure 3.


35/64

PS:232 1983 (R)

( 33 )

1.3.4 Tank. The tank shall contain clean top water which shall be renewed at least every

seven days with water at the specified temperature.

1.3.5 Compression testing machine. The compression testing machine shall be of

suitable capacity for the test and shall be comply generally with the requirements described

in Appendix M. It shall be capable of applying load at the rate specified in 1.7 of thisAppendix. The auxiliary platens shall comply with the requirements of Appendix M.

1.4 Temperature and humidity conditions. The temperature throughout the entire test

procedure shall be controlled about a midpoint of 20oC with permitted variations as shown

in table 1. The minimum relative humidity shall be as given in table 1.

TABLE 1. TEMPERATURE AND HUMIDITY CONDITIONS

Situation Permittedtemperature

variation

Minimumrelative humidity

oC %

Mixing room 2 65

Moist curing chamber 1 90

Water curing tank 1 ---

Compression testing room 2 50

Note. A record should be kept, for reference purposes of the actual temperature and



1.5 Preparation of specimens. The specimens shall be prepared as follows.

1.5.1 Number of cubes. Make three cubes for testing at each of the specified ages.

1.5.2 Aggregate. The sand shall comply with the requirements of Appendix Q of this

Pakistan Standard.

1.5.3 Proportioning. The mass (es) of cement, sand and water for each cube aregiven in table 2.


36/64

PS:232 1983 (R)

( 34 )

TABLE 2. MIXES FOR MORTAR CUBES

Mix

typeMaterial

Proportions by

mass

All cements other than high alumina

cement : mass

VI Cement

Sand

Water

1.0

3.0

0.4

g

185 1

555 1

74 1

High alumina cement:

mass

V2 Cement

Sand

Water

1.0

3.0

0.4

g

190 1

570 1

76 1

1.5.4 Mixing. Before mixing, clamp the assembled mould on the table of the

vibration machine and attach the hopper to the top of the mould. Mix the mortar for each

cube separately on a non-porous surface that has been wiped over with a damp cloth. Mixthe cement and the sand dry, for 1 min, by means of the two trowels. Then add the water and

mix the whole for 4 min with the two trowels.

1.5.5 Compacting. Place the whole of the mortar in the hopper of the mould by the use of

suitable scoop as quickly as possible and compact by vibration for a period of 120 5 s.

1.6 Storage of specimens. Immediately after vibration, remove the hopper and place the

moulds in a single layer on a level surface in the moist curing chamber. In order to reduce

evaporation, cover the exposed top of the cubes with a flat impervious sheet (e.g. clean thinrubber or plastics, or lightly oiled steel) making contact with the upper edge of the mould.

After 240.5 h mark the cubes for later identification and remove from the moulds.Immediately submerge all specimens, except those to be tested at 24 h, in the tank and

arrange them in such a way that the temperature variation specified in table 1 is not

exceeded. Leave the cubes in the tank until just prior to the test.

Specimens to be tested at 24 h are marked and demoulded 15 min to 20 min before

the test and are covered with a damp cloth so that they remain in the moist condition. If the

mortar has not achieved sufficient strength after 24 h to be handled without fear of demage,delay the demoulding for2 further period of 24 h but state this fact in the test report.

1.7 Testing of specimens. Determine the compressive strength of the cubes, under thetemperature and relative humidity conditions specified in table 1 for the compression testing

room, at the specified age, calculated from the time of adding the water to the other

materials, by the procedure specified in Appendix M and using the auxiliary platens,except that the load is applied at a rate of approximately 35 N/mm

2per minute.


37/64


38/64

PS:232 1983 (R)

(36)


39/64

PS:232 1983 (R)

(37)


40/64

PS:232 1983 (R)

(37)

APPENDIX I

METHOD OF TESTING CEMENT DETERMINATION OF STANDARD

CONSISTANCE.

1. TEST PRINCIPALE

The quantity of water required to give a cement paste of standard consistence isdetermined by using the Vicat apparatus.

This quantity of water gives the water content of the pastes for the determination ofsettings times (Appendix J and of soundness Appendix K).

Note. For high alumina cement this test is not carried out and a value of 22% is

assumed.

2. APPARATUS

2.1 Mould. The mould (figure 1) consists of a split ring (E). It shall have an

internal diameter 80.0 0.1 mm and a height of 40.0 0.5 mm. The mould rests on a non-

porous plate which is lightly greased. A metal plate 3 mm thick is suitable.

To ensure interchangeability of the clamping rings, the external diameter at the baseof the mould shall be 89.0 0.1 mm with a taper of 2

oon the side. Total taper shall be 4

o

inwards from base to top. The outer clamping ring is similarly tapered. When assembled,

this ring shall be clear above the base of the mould, by a distance of 15 mm to 18 mm.

2.2 Frame. The frame D (figure 1) bears a movable rod B supporting a cap A andcarrying an indicator which moves over a graduated scale attached to the frame. The other

end of the movable rod has a cylindrical hole and knurled screw the suitable for the insertionof various attachments. There shall be a clearance of about 6 mm between the lower end of

the attachments, when they are raised, and the top edge of the mould to enable the mould to

be located in position without damage to the attachments. The total mass of the moving unit,when in use, complete with attachments, shall be 300 1 g.

2.3 Plunger. The plunger G (figure 1) is of polished brass 10.00 0.05 mm indiameter with a projection at the fitting and for insertion into the movable rod B. Its length

shall be 50 V 1 mm and the lower face is flat. Its mass shall be 9.0 0.5 g.

2.4 Trowels. The trowels shall have a cast steel blade; a suitable type is shown infigure 2.

3. Temperature and humidity conditions keep the temperature of the mixing room at 20V 2

oC and the relative humidity at not less than 65%. Before use, ensure that all materials,

moulds and other appliances are at the same temperature as the air in the mixing room by

storing them in the room for a sufficient time.


41/64

PS:232 1983 (R)

(38)

4. PROCEDURE

4.1 General. Weigh, to 1 g, about 400 g of cement and a measured quantity ofwater. Mix these materials vigorously for 240 5s on a non-porous surface, by means of the

two trowels. Fill the mould with the cement paste within the next 15 s in one layer and

smooth off the surface of the paste level with the top of the mould as quickly as possible. In

filling the mould use gloved hands and the blade of the trowel only. Complete the operationwithin 255 s from the addition of the water to the cement. Immediately after filling the

mould, place it centrally under the movable rod B bearing the plunger G. Lower the plungergently into contact with the surface of the cement paste, then quickly release it and allow it

to sink into the surface. Note the amount of settlement.

4.2 Determination of standard consistence. Make up trial pastes of varying quantities of

water and carry out the procedure specified in 4.1 unit that quantity is found giving a paste

which permits the settlement of the plunger G to a point 5 V 1 mm from the bottom of the

mould. Record the quantity of water used.

5. CALCULATION

Calculate the weight of water required to vive a paste of standard consistence as a

percentage of the mass of the dry cement to the nearest 0.5.

6. REPORT

Report the standard consistence to the nearest 0.5 %.


42/64

PS:232 1983 (R)

(39)


43/64

PS:232 1983 (R)

(40)

APPENDIX J

METHODS OF TESTING CEMENT (SETTING TIMES)

1. TEST PRINCIPLE

The initial and final setting times of cement are determined by using the Vicat

apparatus.

2. APPARATUS

The following apparatus is required.

2.1 Mould. The mould shall comply with the requirements of 2.1 Appendix I

(see figure 1).

2.2 Frame. The Frame shall comply with the requirements of 2.2 of Appendix I (seefigure 1).

2.3 Initial setting time needle. The initial setting time needle, C, which is round, is made

of hardened or tempered steel and shall be of diameter 1.13 0.05 mm. Its effective length,excluding the hilt (fitting end) is 50 1mm and the lower face is falt. Its mass shall be 9.0

0.5 g.

2.4 Final setting time needle. The final setting time needle, F, is made of the same

material and shall have the same mass, shape and section as the needle (C) but it shall be 30 2 mm in length, and be fitted with a metal attachment hollowed out so as to leave a

circular cutting edge 5.0 0.1 mm in diameter.

The depth hollowed out shall be 0.5 0.1 mm. A vent hole 0.76 mm diameter is provided as shown in figure 1. The length of projection of the needle beyond the cutting

edge shall be 0.5 0.1 mm.

2.5 Trowels. Trowels shall comply with the requirements of 2.4 of Appendix I.

3. TEMPERATURE AND HUMIDITY CONDITIONS

The temperature throughout the entire test procedure shall be controlled about a mid

point of 20o

with permitted variations as shown in table 1. The minimum relatives humidityshall be as given in table 1.


44/64

PS:232 1983 (R)

(41)

TABLE 1. TEMPERATURE AND HUMIDITY CONDITIONS

SITUATION PERMITTED

TEMPERATURE

VERIATION

MINIMUM

RELATIVE

HUMIDITY

Mixing roomMoist curing chamber

oC

. . . 2

. . . 1

%

6590

Note. A record should be kept, for reference purposes, of the actual temperature and



4. PROCEDURE

4.1 General. Using the procedure described in 4.1 of Appendix I, mix about 400

g of cement with the quantity of water required to give a paste of standard consistence, fillthe mould within the prescribed time and place immediately in the moist curing chamber.

4.2 Determination of initial setting time. Place the mould under the moveable rod Bbearing the needle C. Lower the needle gently into contact with the surface of the cement

paste, at least 10 mm from the edge of the mould, then quickly release it and allow it to sinkinto the surface. Repeat this process until the needle, when brought into contact with on

undisturbed part of the surface of the cement paste, at least 10 mm from previouspenetrations, and released as described, penetrates to appoint 5 1 mm from the bottom of

the mould. Record the period elapsing between the time when this condition is reached and

the time of adding the water to the cement.

4.3 Determination of final setting time. Replace the needle C by the needle F. Lower the

needle gently into contact with the surface of the cement pasts, then quickly release it andallow it to sink into the surface. Repeat this process until only the needle madkes an

impression on an undisturbed part of the surface of the cement paste, but the attachment

fails to do so. Record the period elapsing between the time when this condition is reachedand the time of adding the water to the cement.

Note. If a scum forms on the surface of the cement paste, the undersite of the specimen

may be used for the determination of final setting time.


45/64

PS:232 1983 (R)

(42)

5. REPORT

REPORT THE INITIAL SETTING TIMES TO THE NEAREST 5 MIN.


46/64

PS:232 1983 (R)

(43)

APPENDIX K

METHODS OF TEDSTING CEMENT SOUNDNESS TEST

1. TESTING PRINCIPLE

The soundness of cement is determined by the Le Chatelier method of measuring

its expansion, either after immersion in cold and in boiling water or, for supersulphatedcement, after immersion in cold water.

2. APPERATUS

The following apparatus is required.

2.1 Small split cylinder (figure 1) of spring brass or other suitable metal of 0.5 mmthickness, forming a mould 30mm internal diemeter and 30 mm high. The inside surface of

the mould shall be thinly coated with mould oil. On either side of the split are attached twopointers (AA). The distance from these ends to the centre of the cylinder shall be 165 mm.The split shall be not more than 0.5 mm wide.

2.2 Two glass plates to cover the mould.

3. PROCEDURE

3.1 Immersion in cold and boiling water. Using the procedure described in 4.1 of

Appendix I mix about 100 g of cement with the quantity of water required to give a pasteof standard consistence. Place the mould on one glass plate and fill it with the cement paste,

taking care to keep the split of the mould gently closed whilst this operation is beingperformed. Next, cover the mould with the other glass plate, upon which a small weight is

placed. Immerse the whole immediately in water at a temperature of 20 1oC and leave

there for 24 0.5h.

Then remove the mould from the water. Measure the distance separating theindicator points to the nearest 0.5 mm and again immerse in water at a temperature of 20 1oC. Bring the water the boiling point in 25 min to 30 min and keep boiling for 1 h. Next

remove the mould from the water and allow to cool. Again measure the distance separatingthe indicator points to the nearest 0.5 mm : the difference between the two measurements

represents the expansion of the cement.

3.2 Immersion in cold water. Using the procedure described in 4.1 of Appendix I, mixabout 100 g of cement with the quantity of water required to give a paste of standard

consistence. Place the mould on one glass plate and fill it with the cement paste, taking care

to keep the split of the mould gently closed whilst this operation is being performed. Thencover the mould with the other glass plate, upon which a small weight is placed. Measure

the distance separating the indicator points to the nearest 0.5 mm. Immerse the whole

immediately in water at a temperature of 20 1oC and leave there for 24 0.5 b.


47/64

PS:232 1983 (R)

(44)

The remove the mould from the water. Measure the distance separating the indicator

points to the nearest 0.5 mm. The difference between the two measurements represents theexpansion of the cement.

4. REPORT

Report the expansion to the nearest 1 mm.

APPENDIX L

METHOD OF TESTING CEMENT SAMPLING

1. SCOPE

of the Pakistan Standard describes methods for obtaining samples of cement

for test purpose from deliveries.

The sampling situations covered by this standard are :

Cement in bags, drums or other packages:

Cement in bulk delivery vehicles:

Cement on discharge from a storage silo.

2. GENERAL

Samples shall be taken using clean, dry equipment and shall be stored in clean, dry,

airtight sample containers.

3. SIZE OF SAMPLES

Samples shall be of 7 kg minimum mass taken in accordance with clause 5.


48/64

PS:232 1983 (R)

(45)

4. REPRESENTATION

The quantity of cement represented by a sample shall not normally exceed 21 t.

When the mass of cement in any container exceeds 21 t, special arrangements, based

on the general principles of the sampling methods described in this standard, shall be agreedbetween the parties concerned.

5. SAMPLING METHODS

5.1 Cement in bags, drums or other packages. Samples shall consist of at least five sub-

samples obtained, if possible, from different containers. The containers to be sampled shallbe selected by :

(a) allocating, in a systematic order, a number to each container in the delivery :

(b) dividing the total number of containers by the number of sub-samples

required to identify different parts of the delivery.

(c) Selecting at random from each part, a container to be sampled.When there are fewer than five containers, each container shall be sampled and

approximately the same quantity of cement shall be taken from each container.

The use of a sampling tube is preferred.

5.1.1 Sampling by sampling tube. A suitable form of tube is shown in figure 1. Marks on

the collars of both tubes correspond to the center line of the slots so that, then the mark onthe inner tube is lined up with the mark on the outer tube, the slots are open.

The closed sampling tube shall be inserted into an opened container and driven intothe cement. The tube shall then be opened and rotated until it takes a full core of cement

from substantially the entire length of the container.

5.1.2 Sampling by other methods. When no sampling tube is available, the container shallbe opened and a sub-sample taken by means of a scoop or other appropriate tool.


49/64

PS:232 1983 (R)

(46)

5.2 Cement in a bulk-delivery vehicle. A sample shall be obtained by use of sampling

ladle. A suitable form of ladle shown in figure 2. Before any cement is discharged, theinspection cover on the top of the delivery vehicle shall be removed.

The top 150 mm (approximately) of the cement shall be) scraped aside. The exposedsurface shall be sampled by lading from it a sufficient number of sub-samples. The ladle

shall not be overfilled and care shall be exercised to avoid loss of any part of a sub-sample

when transferring it from the ladle to the sample container.

5.3 Cement from the discharge of a storage silo.

A sub-sample shall be obtained from the silo discharge by use of a scoop or other

appropriate tool. At least three sub-samples shall be taken evenly spaced through the

discharge from the silo. The sub-samples shall be combined to form the sample.

A sample of cement taken from a silo shall be taken as representing only the quantityof the cement discharged at the time of sampling. It shall not be taken as representing a

particular batch or delivery of cement to the silo unless the silo is known to contain no other

cement.

6. STORAGE AND DELIVERY OF SAMPLES

Immediately after being taken, the sample shall be stored in a clean, dry, airtightcontainer made of metal or glass. The volume of air remaining in the filled container shall

be the minimum practicable.

7. CERTIFICATE OF SAMPLING

The sample shall be accompanied by a certificate of sampling on which shall berecorded information identifying the material and the method of sampling.

The general form of certification is shown in figure 3.


50/64

PS:232 1983 (R)

(47)


51/64

PS:232 1983 (R)

(48)

(a) Side view (b) Front view

Approximate dimensions of sampling ladle

Diameter 225 mm.Depth of ladle 175 mm.Handle Length 1800 mm

Figure 2. Typical sampling ladle


52/64

PS:232 1983 (R)

(49)

PS: 232:1982 (Revised) Appendix L

Certificate of samplingIn accordance with PS : 232 : 1983 (Revised) Appendix L

Material

Type of cement

Source of supply

Nature and size of consignment sampled

Identification of consignment sampled

SAMPLING

Date of sampling

Method of sampling

Name and signature of sampler

Figure 3. Certificate of sampling

APPENDIX M

TESTING MACHINE TEST FOR CEMENT

Compression Testing Machine, ehe Testing Machine may be of any reliable type ofsuitable Capacity for the test and capable, of applying the load at the Rate Specified in 2.1.3.

The testing machine shall be equipped with two rigid bearing platens made of amaterial which will not deform irreversible or wear excessively in normal size. They shall

be at least as large as the nominal size of the specimen to which the load is applied.

The upper machine platen shall be able to align freely as contact is made with thespecimen, but the platens shall be restrained (by friction or other means) from tilting with

respect to each other during loading.

The flatness tolerance (flatness 1) for the area to be in compact with the specimen

shall be 0.03 mm wide and the surface texture shall be 3.2 mm CLA.


53/64

PS:232 1983 (R)

(50)

1.1 Auxiliary platens. An auxiliary platen 25.0 0.4 mm thick may be interposed

between the specimen and each machine platen. The upper auxiliary platen shall rest on thespecimen and not be attached to the upper machine platen.

1.1.1 Material. The platens shall be made of a material which will not deform irreversiblyor wear excessively in normal use.

1.1.2 Tolerances. The platens shall be such that they are accurate within the following

limits :

(1) Dimensions. The distance between either pair of opposite edges, based onthe average of four symmetrically placed measurements, shall be the nominalsize of the specimen + 0.2 mm. O.Omm

(2) Flatness. The flatness tolerance (flatness 1) for each contact face shall be0.03 mm wide.

(3) Square ness. The square ness tolerance (square ness 1) for each edge with

respect to the adjacent edge as datum edge shall be 0.5 mm wide.

(4) Parallelism. The parallelism tolerance (parall

pakistan cement standar ps%20232-1983%20(rev)

Documents