BS-EN-1936-2006.pdf

BRITISH STANDARD BS EN 1936:2006 Natural stone test methods Determination of real density and apparent density, and of total and open porosity The European Standard EN 1936:2006 has the status of a British Standard ICS 73.020; 91.100.15 ? Licensed Copy: London South Bank University, London South Bank University, Thu Jan 18 01:22:54 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS EN 1936:2006 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2007 © BSI 2007 ISBN 978-0-580-49919-7 National foreword This British Standard was published by BSI. It is the UK implementation of EN 1936:2006. It supersedes BS EN 1936:1999 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee B/545, Natural stone. A list of organizations represented on B/545 can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Thu Jan 18 01:22:54 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 1936 December 2006 ICS 73.020; 91.100.15Supersedes EN 1936:1999 English Version Natural stone test methods - Determination of real density and apparent density, and of total and open porosity Méthodes d'essai des pierres naturelles - Détermination des masses volumiques réelle et apparente et des porosités ouvertes et totale Prüfverfahren für Naturstein - Bestimmung der Reindichte, der Rohdichte, der offenen Porosität und der Gesamtporosität This European Standard was approved by CEN on 25 October 2006. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the 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 a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels © 2006 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1936:2006: E Licensed Copy: London South Bank University, London South Bank University, Thu Jan 18 01:22:54 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 1936:2006 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references4 3 Principle4 4 Terms and definitions .4 5 Symbols5 6 Apparatus .5 7 Preparation of the specimens 6 7.1 Sampling.6 7.2 Test specimens6 7.3 Drying the specimens .6 8 Test procedure.6 8.1 Open porosity and apparent density.6 8.2 Real density7 8.2.1 General7 8.2.2 Method A (pycnometer).7 8.2.3 Method B (Le Chatelier volumenometer) 7 9 Expression of results 8 9.1 General8 9.2 Apparent density8 9.3 Open porosity.8 9.4 Real density8 9.5 Total porosity.9 10 Test report9 Bibliography11 Licensed Copy: London South Bank University, London South Bank University, Thu Jan 18 01:22:54 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 1936:2006 (E) 3 Foreword This document (EN 1936:2006) has been prepared by Technical Committee CEN/TC 246 “Natural stones”, the secretariat of which is held by UNI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2007, and conflicting national standards shall be withdrawn at the latest by June 2007. This document supersedes EN 1936:1999. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: London South Bank University, London South Bank University, Thu Jan 18 01:22:54 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 1936:2006 (E) 4 1 Scope This European standard specifies methods for determining the real density, apparent density, and open and total porosity of natural stone. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12670:2001, Natural stone - Terminology ISO 3507, Laboratory glassware - Pyknometers 3 Principle After drying to constant mass, the apparent density and open porosity are determined by vacuum assisted water absorption and submerged weighing of specimens. The real density and total porosity require the specimen to be pulverised. 4 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12670:2001 and the following apply. 4.1 apparent density (b) ratio between the mass of the dry specimen and its apparent volume 4.2 apparent volume volume limited by the external surface of the specimen, including any voids 4.3 volume of the solid part difference between the apparent volume of the specimen and the volume of the voids (open and closed pores) 4.4 real density (r) ratio between the mass of the dry specimen and the volume of its solid part 4.5 open porosity ratio (as a percentage) between the volume of the open pores and the apparent volume of the specimen 4.6 total porosity ratio (as a percentage) between the volume of pores (open and closed) and the apparent volume of the specimen Licensed Copy: London South Bank University, London South Bank University, Thu Jan 18 01:22:54 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 1936:2006 (E) 5 5 Symbols md mass of the dry specimen, in grams; mh mass of the specimen immersed in water, in grams; ms mass of the saturated specimen, in grams; me mass of the specimen ground and dried (for the tests using the pycnometer or the volumenometer), in grams; m1 mass of the pycnometer filled with water and the ground specimen, in grams; m2 mass of the pycnometer filled with water, in grams; Vb apparent volume of the specimen, in millilitres; Vo volume of open pores of the specimen, in millilitres; Vs volume of liquid displaced by the mass me (volumenometer test); b apparent density of the specimen, in kilograms per cubic metre; r real density of the specimen, in kilograms per cubic metre; rh density of water, in kilograms per cubic metre; po open porosity of the specimen, as a percentage; p total porosity of the specimen, as a percentage. 6 Apparatus 6.1 A ventilated oven which maintain a temperature (70 ± 5) °C. 6.2 An evacuation vessel which can maintain a pressure of (2,0 ± 0,7) kPa = (15 ± 5) mm Hg and allow gradual immersion of the contained specimens. 6.3 A weighing instrument which has an accuracy of at least 0,01% of the mass to be weighed, also capable of weighing the specimen in water. 6.4 A linear measuring device with an accuracy of at least 0,01%. 6.5 An ISO 3507 type 3 pycnometer having a nominal capacity of 50 ml. 6.6 A La Chatelier type volumenometer consisting of a flat-bottomed flask with a tube graduated form 0 ml to 24 ml in 0,1 ml graduations. 6.7 A sieve with a 0,063 mm mesh. 6.8 A dessicator with dessicant. Licensed Copy: London South Bank University, London South Bank University, Thu Jan 18 01:22:54 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 1936:2006 (E) 6 7 Preparation of the specimens 7.1 Sampling The sampling is not the responsibility of the test laboratory except where specially requested. At least six test specimens, representing the body of stone being tested, shall be selected. 7.2 Test specimens The test specimens can be in the form of a cylinder, cube or prism and must be obtained by diamond sawing or coring. Their apparent volume calculated by geometrical measurements shall be at least 60 ml. In addition, the surface area to volume ratio shall be between 0,08 mm-1 and 0,20 mm-1. NOTE The specimens prepared for the determination of compressive or flexural strength can be used if they satisfy the surface/volume ratio. 7.3 Drying the specimens The specimens are to be dried at (70 ± 5)°C until a constant mass is reached. This is assumed to have been attained when the difference between the two weighings at an interval of (24 ± 2) h is not greater than 0,1 % of the mass of the specimen. The specimens shall be kept in a desiccator until room temperature is attained. 8 Test procedure 8.1 Open porosity and apparent density Weigh each specimen (md), then put the specimens into an evacuation vessel and lower the pressure gradually to (2,0 ± 0,7) kPa = (15 ± 5) mm Hg. Maintain this pressure for (2 ± 0,2) h in order to eliminate the air contained in the open pores of the specimens. Slowly introduce demineralized water at (20 ± 5)°C into the vessel (the rate at which the water rises shall be such that the specimens are completely immersed not less than 15 min). Maintain the pressure of (2,0 ± 0,7) kPa during the introduction of water. When all the specimens are immersed, return the vessel to atmospheric pressure and leave the specimens under water for another (24 ± 2) h at atmospheric pressure. Then, for each specimen: weigh the specimen under water and record the mass in water: mh; quickly wipe the specimen with a dampened cloth and determine the mass ms of the specimen saturated with water. In the case of natural stones with visible cavities (e.g. travertine) the apparent volume is determined by measuring the dimensions of the specimens to the nearest millimetre. Licensed Copy: London South Bank University, London South Bank University, Thu Jan 18 01:22:54 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 1936:2006 (E) 7 8.2 Real density 8.2.1 General For dense, low porosity stones the differences between real and apparent density, as well as between open porosity and total porosity, are very small. For these stones it is sufficient to determine the apparent density and the open porosity. In the case of control of supplies the decision of omitting the determination of the real density shall be agreed upon between the parties. In this standard two methods for the determination of real density are described: the pycnometer (Method A) and Le Chatelier volumenometer (Method B). The first method is more accurate but requires a very long time. It is suggested to use it as a reference method in the case of controversy. Le Chatelier volumenometer method is less accurate but easy and rapid to perform and can be used for production control. 8.2.2 Method A (pycnometer) For each specimen, after having determined the apparent density and the open porosity, grind each specimen separately until the particles pass through a sieve with 0,063 mm mesh. Dry the ground specimen to a constant mass and set apart a mass, me of approximately 10 g weighed to an accuracy of ± 0,01 g. Introduce deionized water into the pycnometer and fill it approximately half full. Then add the weighed mass, me of the ground specimen into the pycnometer and agitate the liquid to disperse the solid matter. NOTE Ethanol or other liquids may be used instead of deionised water if required. In this case the density of this liquid shall be used instead of density of water in the equation (5a). Expose the pycnometer to a vacuum of (2 ± 0,7) kPa until no further air bubbles rise, then fill it with deionized water almost to the top and leave the solid matter to settle until the water above the residue is clear. Next, carefully top up the pycnometer with deionized water, fit the ground stopper and gently wipe off any overflow. Finally weigh the pycnometer to an accuracy of ± 0,01 g (m1). Empty and wash the pycnometer, fill it with deionized water only and weigh to an accuracy of ± 0,01 g (m2). Before each weighing make sure that the ambient air temperature is (20 ± 5)°C. 8.2.3 Method B (Le Chatelier volumenometer) For each specimen, after having determined the apparent density and the open porosity, grind each specimen separately until the particles will pass through a sieve with 0,063 mm mesh. Dry the ground specimen to a constant mass and set apart a mass, me of approximately 50 g weighed to an accuracy of ± 0,1 g. Introduce deionized water into Le Chatelier volumenometer until the level is up to the 0 graduation. Then add the weighed mass, me of the ground specimen into the volumenometer in five fractions in the region of 10 g each, ensuring that all of each fraction falls into the liquid. After the introduction of each fraction, agitate the liquid to disperse the ground specimen. Read the graduations to determine the Vs in millilitres to the nearest 0,1 ml of liquid displaced by the mass me of the ground specimen. Before taking the initial at 0 level and final volume readings make sure that the ambient air temperature is (20 ± 5)°C. Licensed Copy: London South Bank University, London South Bank University, Thu Jan 18 01:22:54 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 1936:2006 (E) 8 9 Expression of results 9.1 General The volume of the open pores (in millilitres) is expressed by the equation: 1000 mm V rh ds 0 × = (1) The apparent volume (in millilitres) is expressed by the equation: 1000 mm V rh hs b × = (2) which can alternatively be calculated on the basis of the dimensions of the specimen. NOTE The value of the density of water rh at 20 °C is 998 kg/m3 apparent density. 9.2 Apparent density The apparent density (in kilograms per cubic metre) is expressed by the ratio of the mass of the dry specimen and its apparent volume, by the equation: rh hs d b mm m × = (3) 9.3 Open porosity The open porosity is expressed by the ratio (as a percentage) of the volume of open pores and the apparent volume of the specimen, by the equation: 100 mm mm p hs ds o × = (4) 9.4 Real density The real density (in kilograms per cubic metre