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BRITISH STANDARD BS EN1936:1999

The European Standard EN 1936:1999 has the status of aBritish Standard

ICS 91.100.15

NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW

Natural stone testmethods ÐDetermination of realdensity and apparentdensity, and of total andopen porosity

This British Standard, havingbeen prepared under thedirection of the SectorCommittee for Building and CivilEngineering, was published underthe authority of the StandardsCommittee and comes into effecton 15 September 1999

BSI 09-1999

ISBN 0 580 32293 9

BS EN 1936:1999

Amendments issued since publication

Amd. No. Date Comments

National foreword

This British Standard is the English language version of EN 1936:1999.

The UK participation in its preparation was entrusted to Technical CommitteeB/545, Natural stone, which has the responsibility to:

Ð aid enquirers to understand the text;

Ð present to the responsible international/European committee any enquirieson the interpretation, or proposals for change, and keep the UK interestsinformed;

Ð monitor related international and European developments and promulgatethem in the UK.

A list of organizations represented on this committee can be obtained on request toits secretary.

Cross-references

The British Standards which implement international or European publicationsreferred to in this document may be found in the BSI Standards Catalogue under thesection entitled ªInternational Standards Correspondence Indexº, or by using theªFindº facility of the BSI Standards Electronic Catalogue.

A British Standard does not purport to include all the necessary provisions of acontract. Users of British Standards are responsible for their correct application.

Compliance with a British Standard does not of itself confer immunityfrom legal obligations.

Summary of pages

This document comprises a front cover, an inside front cover, the EN title page,pages 2 to 5 and a back cover.

The BSI copyright notice displayed throughout this document indicates when thedocument was last issued.

CENEuropean Committee for Standardization

Comite EuropeÂen de Normalisation

EuropaÈisches Komitee fuÈ r Normung

Central Secretariat: rue de Stassart 36, B-1050 Brussels

1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN nationalMembers.

Ref. No. EN 1936:1999 E

EUROPEAN STANDARD EN 1936

NORME EUROPEÂ ENNE

EUROPAÈ ISCHE NORM March 1999

ICS 73.020; 91.100.15

English version

Natural stone test methods Ð Determination of real density andapparent density, and of total and open porosity

MeÂthodes d'essai pour pierres naturelles ÐDeÂtermination des masses volumiques reÂelle etapparente et des porositeÂs ouverte et totale

PruÈfverfahren fuÈr Naturstein Ð Bestimmung derReindichte, der Rohdichte, der offenen PorositaÈtund der GesamtporositaÈt

This European Standard was approved by CEN on 13 February 1999.

CEN members are bound to comply with the CEN/CENELEC Internal Regulationswhich stipulate the conditions for giving this European Standard the status of anational standard without any alteration. Up-to-date lists and bibliographicalreferences concerning such national standards may be obtained on application tothe Central Secretariat or to any CEN member.

This European Standard exists in three official versions (English, French, German).A version in any other language made by translation under the responsibility of aCEN member into its own language and notified to the Central Secretariat has thesame status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland andUnited Kingdom.

Page 2EN 1936:1999

BSI 09-1999

Foreword

This European Standard has been prepared byTechnical Committee CEN/TC 246, Natural stones, theSecretariat of which is held by UNI.

This European Standard shall be given the status of anational standard, either by publication of an identicaltext or by endorsement, at the latest bySeptember 1999, and conflicting national standardsshall be withdrawn at the latest by September 1999.

This European Standard is one of the series of draftstandards for tests on natural stone. Test methods fornatural stone consist of the following parts:

EN 1925, Natural stone test methods Ð Determinationof water absorption coefficient by capillarity.

EN 1926, Natural stone test methods Ð Determinationof compressive strength.

EN 12370, Natural stone test methods ÐDetermination of resistance to salt crystallization.

prEN 12371, Natural stone test methods ÐDetermination of frost resistance.

EN 12372, Natural stone test methods ÐDetermination of flexural strength under concentratedload.

prEN 12407, Natural stone test methods ÐPetrographic description.

prEN 13161, Natural stone test methods ÐDetermination of flexural strength under constantmoment.

prEN 13364, Natural stone test methods ÐDetermination of the breaking load at a dowel hole.

prEN ... (WI 00246011), Natural stone test methods ÐDetermination of thermal dilatation coefficient.

prEN ... (WI 00246012), Natural stone test methods ÐDetermination of sound±speed propagation.

prEN ... (WI 00246014), Natural stone test methods ÐDetermination of abrasion resistance.

prEN ... (WI 00246015), Natural stone test methods ÐDetermination of Knoop hardness.

prEN ... (WI 00246016), Natural stone test methods ÐDetermination of thermal shock resistance.

prEN ... (WI 00246017), Natural stone test methods ÐDetermination of slip coefficient.

prEN ... (WI 00246018), Natural stone test methods ÐDetermination of static elastic modulus.

prEN ... (WI 00246019), Natural stone test methods ÐDetermination of rupture energy.

prEN ... (WI 00246030), Natural stone test methods ÐDetermination of surface finishes (rugosity).

prEN 13373, Natural stone test methods ÐDetermination of geometric characteristics on units.

prEN ... (WI 00246032), Natural stone test methods ÐDetermination of resistance to ageing by salt mist.

prEN ... (WI 00246033), Natural stone test methods ÐDetermination of resistance to ageing by humidity,temperature, SO2 action.

prEN ... (WI 00246035) Natural stone test methods ÐDetermination of dynamic elastic modulus (byfundamental resonance frequency).

prEN ... (WI 00246036) Natural stone test methods ÐDetermination of water absorption at atmosphericpressure.

It is intended that other ENs should call up thisEN 1936 as the basis of evaluation of conformity.(Nevertheless it is not intended that all natural stonesproducts should be subjected regularly to all the listedtests. Specifications in other standards should call uponly relevant test methods).

According to the CEN/CENELEC Internal Regulations,the national standards organizations of the followingcountries are bound to implement this EuropeanStandard: Austria, Belgium, Czech Republic, Denmark,Finland, France, Germany, Greece, Iceland, Ireland,Italy, Luxembourg, Netherlands, Norway, Portugal,Spain, Sweden, Switzerland and the United Kingdom.

Contents

Page

Foreword 2

1 Scope 3

2 Normative references 3

3 Principle 3

4 Definitions 3

5 Symbols 3

6 Apparatus 3

7 Preparation of the specimens 4

8 Test procedure 4

9 Expression of results 5

10 Test report 5

Page 3EN 1936:1999

BSI 09-1999

1 ScopeThis European Standard specifies methods ofdetermining the real density, the apparent density, andthe open and total porosity of natural stone.

2 Normative referencesThis European Standard incorporates by dated orundated reference, provisions from other publications.These normative references are cited at theappropriate places in the text and the publications arelisted hereafter. For dated references, subsequentamendments to or revisions of any of thesepublications apply to this European Standard onlywhen incorporated in it by amendment or revision. Forundated references, the latest edition of the publicationreferred to applies.

prEN 12670, Natural stones Ð Terminology.

ISO/DIS 3507, Laboratory glassware Ð Pyknometers.

prEN 12440, Denomination of natural stone.

3 PrincipleAfter drying to constant mass, the apparent densityand the open porosity are determined by vacuumassisted water absorption and submerged weighing ofspecimens. The real density and the total porosityrequire the specimen to be pulverized.

4 DefinitionsFor the purposes of this standard the followingdefinitions and the definitions in accordance withprEN 12670 apply.

4.1

apparent density (rb)

the ratio between the mass of the dry specimen and itsapparent volume

4.2

apparent volume

the volume limited by the external surface of thespecimen, including any voids

4.3

volume of the solid part

the difference between the apparent volume of thespecimen and the volume of the voids (open andclosed pores)

4.4

real density (rr)

the ratio between the mass of the dry specimen andthe volume of its solid part

4.5

open porosity

the ratio (as a percentage) between the volume of theopen pores and the apparent volume of the specimen

4.6

total porosity

the ratio (as a percentage) between the volume ofpores (open and closed) and the apparent volume ofthe specimen

5 Symbols

md mass of the dry specimen, in grams;

me mass of the specimen ground and dried(for the tests using the pycnometer or thevolumenometer), in grams;

mh mass of the specimen immersed in water, ingrams;

ms mass of the saturated specimen, in grams;

m1 mass of the pycnometer filled with water andthe ground specimen, in grams;

m2 mass of the pycnometer filled with water, ingrams;

Vb apparent volume of the specimen, in millilitres;

Vo volume of open pores of the specimen, inmillilitres;

Vs volume of liquid displaced by the mass me(volumenometer test);

rb apparent density of the specimen, in kilogramsper cubic metre;

rr real density of the specimen, in kilograms percubic metre;

rrh density of water, in kilograms per cubic metre;

p total porosity of the specimen, as apercentage;

po open porosity of the specimen, as apercentage.

6 Apparatus

6.1 A ventilated oven, which can maintain atemperature of (70 ± 5) 8C.

6.2 An evacuation vessel, which can maintain apressure of (2,0 ± 0,7) kPa = (15 ± 5) mm Hg and allowgradual immersion of the contained specimens.

6.3 A weighing instrument, which has an accuracy ofat least 0,01 % of the mass to be weighed, also capableto weigh the specimen in water.

6.4 A linear measuring device, with an accuracyof 0,1 mm.

6.5 An ISO/DIS 3507 type 3 pycnometer, having anominal capacity of 50 ml.

6.6 A Le Chatelier type volumenometer, consisting ofa flat-bottomed flask with a tube graduated from 0 mlto 24 ml in 0,1 ml graduations.

6.7 A sieve, with a 0,063 mm mesh.

6.8 A desiccator, with desiccant.

Page 4EN 1936:1999

BSI 09-1999

7 Preparation of the specimens

7.1 Sampling

The sampling is not the responsibility of the testlaboratory except where specially requested. At leastsix test specimens, which are consideredrepresentative of the body of stone being tested, shallbe selected.

7.2 Test specimens

The test specimens have the form of a cylinder, cubeor prism and shall be obtained by diamond sawing orcoring. Their apparent volume calculated bygeometrical measurements shall be at least 25 ml.

In addition, the surface area to volume ratio shall bebetween 0,1 mm21 and 0,2 mm21.

NOTE The specimens prepared for the determination ofcompressive or flexural strength can be used if they satisfy thesurface/volume ratio.

7.3 Drying the specimens

The specimens are to be dried at a temperature of(70 ± 5) 8C until a constant mass is reached. This isassumed to have been attained when the differencebetween two weighings at an interval of (24 ± 2) h isnot greater than 0,1 % of the mass of the specimen.

The specimens shall be kept in a desiccator until roomtemperature is attained.

8 Test procedure

8.1 Open porosity and apparent density

Weigh each specimen (md), then put the specimensinto an evacuation vessel and lower the pressuregradually to (2,0 ± 0,7) kPa = (15 ± 5) mm Hg.

Maintain this pressure for (24 ± 2) h in order toeliminate the air contained in the open pores of thespecimens.

Introduce demineralized water at (20 ± 5) 8C slowlyinto the vessel (the rate at which the water rises shallbe such that the specimens are completely immersedin not less than 15 min).

Maintain the pressure of (2,0 ± 0,7) kPa duringintroduction of water and for (24 ± 2) h afterwards.

After this time return the vessel to atmosphericpressure and leave the specimens under water foranother (24 ± 2) h at atmospheric pressure.

Then, for each specimen:

Ð weigh the specimen under water and record themass in water: mh;

Ð quickly wipe the specimen with a dampenedcloth and determine the mass ms of the specimensaturated with water.

In the case of natural stones with visible cavities(e.g. travertine) the apparent volume is determined bymeasuring the dimensions of the specimens to thenearest millimetre.

8.2 Real density

8.2.1 General

For dense, low porosity stones the differences betweenreal and apparent density, as well as between openporosity and total porosity, are very small. For thesestones it is sufficient to determine the apparent densityand the open porosity. In the case of control ofsupplies the decision of omitting the determination ofthe real density shall be agreed upon between theparties.

In this standard two methods for the determination ofreal density are described: the pycnometer (Method A)and Le Chatelier volumenometer (Method B).

The first method is more accurate but requires a verylong time. It is suggested to use it as a referencemethod in the case of controversy. Le Chateliervolumenometer method is less accurate but easy andrapid to perform and can be used for productioncontrol.

8.2.2 Method A (pycnometer)

For each specimen, after having determined theapparent density and the open porosity, grind eachspecimen separately until the particles will passthrough a sieve with 0,063 mm mesh.

Dry the ground specimen to a constant mass and setapart a mass me of approximately 25 g weighed to anaccuracy of ± 0,01 g.

Introduce deionized water into the pycnometer and fillit until approximately half full. Then add the weighedmass me of the ground specimen into the pycnometerand agitate the liquid to disperse the solid matter.

Expose the pycnometer to a vacuum of (2 ± 0,7) kPauntil no further air bubbles rise, then fill it withdeionized water almost to the top and leave the solidmatter to settle until the water above the residue isclear.

Next, carefully top up the pycnometer with deionizedwater, fit the ground stopper and gently wipe off anyoverflow. Finally weigh the pycnometer to an accuracyof ± 0,01 g (m1).

Empty and wash the pycnometer, fill it with deionizedwater only and weigh to an accuracy of ± 0,01 g (m2).

Before each weighing make sure that the ambient airtemperature is (20 ± 5) 8C.

8.2.3 Method B (Le Chatelier volumenometer)

For each specimen, after having determined theapparent density and the open porosity, grind eachspecimen separately until the particles will passthrough a sieve with 0,063 mm mesh.

Dry the ground specimen to a constant mass and setapart a mass me of approximately 50 g weighed to anaccuracy of ± 0,1 g.

Page 5EN 1936:1999

BSI 09-1999

Introduce deionized water into Le Chateliervolumenometer until the level is up to the 0 graduation.Then add the weighed mass me of the groundspecimen into the volumenometer in five fractions inthe region of 10 g each, ensuring that all of eachfraction falls into the liquid. After the introduction ofeach fraction, agitate the liquid to disperse the groundspecimen. Read the graduations to determine the Vs inmillilitres to the nearest 0,1 ml of liquid displaced bythe mass me of the ground specimen.

Before taking the initial at 0 level and final volumereadings make sure that the ambient air temperatureis (20 ± 5) 8C.

9 Expression of results

9.1 General

The volume of the open pores (in millilitres) isexpressed by the equation:

(1)Vo = 3 1 000ms 2 md

rrh

The apparent volume (in millilitres) is expressed by theequation:

(2)Vb = 3 1 000m2mh

rrh

which can alternatively be calculated on the basis ofthe dimensions of the specimen.

NOTE The value of the density of water rrh at 20 8C is 998 kg/m3.

9.2 Apparent density

The apparent density (in kilograms per cubic metre) isexpressed by the ratio of the mass of the dry specimenand its apparent volume, by the equation:

(3)rb = 3 rrhmd

ms 2 mh

9.3 Open porosity

The open porosity is expressed by the ratio (as apercentage) of the volume of open pores and theapparent volume of the specimen, by the equation:

(4)po = 3 100ms 2 md

ms 2 mh

9.4 Real density

The real density (in kilograms per cubic metre) isexpressed by the ratio of the mass of the ground dryspecimen me to the volume of liquid displaced by themass me, by the equations:

Method A (pycnometer)

(5a)rr = 3 rrhme

m2 + me2 m1

Method B (Le Chatelier volumenometer)

(5b)rr = 3 rrhme

Vs

9.5 Total porosityThe total porosity is expressed by the ratio (as apercentage) of the volume of pores (open and closed)and the apparent volume of the specimen, by theequation:

(6)p = 3 100 = 3 100

21

rb

1

rr

1

rb

12

rb

rr

10 Test reportThe test report shall contain the following information:

a) unique identification number of the report;

b) the number, title and date of issue of thisEuropean Standard;

c) the name and address of the test laboratory andthe address where the test was carried out ifdifferent from the test laboratory;

d) the name and address of the client;

e) it is the responsibility of the client to supply thefollowing information:

Ð the petrographic name of the stone;

Ð the commercial name of the stone inaccordance with prEN 12440;

Ð the country and region of extraction;Ð the name of the supplier;Ð the direction of any existing plane ofanisotropy (if relevant to the test) to be clearlyindicated on the sample or on each specimen bymeans of two parallel lines;Ð the name of the person or organization whichcarried out the sampling;Ð the surface finish of the specimens (if relevantto the test);

f) the date of delivery of the sample or of thespecimens;g) the date when the specimens were prepared(if relevant) and the date of testing;h) the number of specimens in the sample;i) the dimensions of the specimens;j) for each specimen: the real density (if determined)and the apparent density to the nearest 10 kg/m3, theopen porosity and the total porosity (if determined)to the nearest 0,1 %;k) the arithmetic mean of the individual values forthe real density (if determined) and for the apparentdensity (to the nearest 10 kg/m3), for the openporosity and for the total porosity (if determined)(to the nearest 0,1 %);l) the method used for the determination of the realdensity (when relevant);m) all deviations from the standard and theirjustification;n) remarks.

The test report shall contain the signature(s) androle(s) of the responsible(s) for the testing and thedate of issue of the report. It shall also state that thereport shall not be partially reproduced without thewritten consent of the test laboratory.

BS EN1936:1999

BSI389 Chiswick High RoadLondonW4 4AL

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