ICS 73.020; 91.100.15  
 
Reference number
DRS 549: 2023
© RSB 2023
  
 RWANDA 
STANDARD  DRS 
549 
 
1th edition 
2023-mm-dd  
 
Natural stone test method — 
Determination of water absorption at 
atmospheric pressure 
   
DRS 549: 2023 
©RSB 2023- All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition 
 
 
 
 
 
 
 
 
© RSB2023 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from RSB. 
Requests for permission to reproduce this document should be addressed to: 
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Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw  DRS 549: 2023 
iii                ©RSB 2023- All rights reserved 
 Contents Page 
Foreword ............................................................................................................................................................ iv  
1 Scope ...................................................................................................................................................... 1  
2 Normative references ............................................................................................................................ 1  
3 Terms and definitions ........................................................................................................................... 1  
4 Principle ................................................................................................................................................. 1  
5 Symbols .................................................................................................................................................. 1  
6 Apparatus ............................................................................................................................................... 1  
7 Preparation of the specimens .............................................................................................................. 2  
7.1 Sampling ................................................................................................................................................ 2  
7.2 Test specimens ...................................................................................................................................... 2  
7.3 Drying the specimens ........................................................................................................................... 2  
8 Test procedure ....................................................................................................................................... 2  
9 Expression of results ............................................................................................................................ 3  
10 Test report .............................................................................................................................................. 3  
. DRS 549: 2023 
©RSB 2023- All rights reserved                  iv 
 Foreword 
Rwanda Standardsarepreparedby Technical Committees and approved by Rwanda Standards Board (RSB) 
Board of Directors in accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards. 
The main task of technical committees is to prepare national standards. Final Draft Rwanda Standards 
adopted by technical committees are ratified by members of RSB Board of Directors for publication and 
gazettment as Rwanda Standards. 
DRS549 was prepared by Technical Committee RSB/TC 9, Civil engineering and building materials.  
In the preparation of this standard, reference was made to the following standard (s): 
1) BS EN 13755:2008: Natural stone test methods - Determination of water absorption at atmospheric 
pressure 
The assistance derived from the above source is hereby acknowledged with thanks. 
DRS549 consists of the following parts, under the general title Natural stone test methods - Determination of 
water absorption at atmospheric pressure : 
Committee membership  
The following organizations were represented on the Technical Committee on Civil engineering and Building 
materials (RSB/TC 9) in the preparation of this standard. 
A+Construction Group Ltd 
Africeramics Ltd 
Consultants Engineers Group (CEG) Ltd 
D&D Resources Ltd 
Dutureheza Ltd 
Enabel Rwanda 
Greenpack Africa Ltd 
Integrated Polytechnic Regional Centre (IPRC) - Musanze  
Mass Design Group DRS 549: 2023 
v                ©RSB 2023- All rights reserved 
 NP Construction Company (NPCC) Ltd 
Road Transport Development Agency (RTDA) 
Rwanda Housing Authority (RHA) 
Rwanda Inspectorate, Competition and Consumer Protection Authority (RICA) 
Rwanda Quarries Association (RQA) 
SKAT Consult  
St Joseph Engineering Company (SJEC) Ltd 
Standards for Sustainability (SfS) 
Stonecraft Industries Ltd 
University of Rwanda - College of Science and Technology (UR - CST) 
Rwanda Standards Board(RSB) – Secretariat 
 
 DRS 549: 2023 
1                ©RSB 2023- All rights reserved 
 Natural stone test methods - Determination of water absorption at 
atmospheric pressure 
1 Scope 
This Draft Rwanda standard specifies a method for determining the water absorption of natural stone – see 
DRS 515 for terminology and DRS 5278 for denomination - by immersion in water at atmospheric pressure. 
2 Normative references 
The following documents are referred to in the text in such a way that some or all of their content constitutes 
requirements of this document. For dated references, only the editioncited applies. For undated references, 
the latest edition of the referenced document (including any amendments) applies. 
DRS 528, Natural stone test methods: Denomination criteria 
DRS 515, Natural stone – Terminology 
3 Terms and definitions 
For the purposes of this standard, the terms and definitions given inDRS 515 and DRS 528apply. 
4 Principle 
After drying to a constant mass, each specimen is weighed and then immersed in water at atmospheric 
pressure for a specified period of time. Determination of the water absorption at atmospheric pressure, 
expressed as a percentage, by the ratio of the mass of the saturated specimen (obtained at constant mass) to 
the mass of the dry specimen.  
5 Symbols 
md      mass of the dry specimen, in grams;  
mi successive masses of the specimen during testing, in grams;  
ms       mass of the saturated specimen (after immersion in water until constant mass is reached), in grams;  
Ab       water absorption at atmospheric pressure, expressed as a percentage.  
6 Apparatus 
5.1 A tank with flat base comprising small non-oxidising and non-absorbent supports for the specimens.   
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 5.2   A ventilated oven which can maintain a temperature of (70 ± 5) °C.  
5.3   A weighing instrument with an accuracy of 0.01 g.  
7 Preparation of the specimens 
7.1 Sampling 
The sampling is not under the responsibility of the test laboratory except where especially requested.  
At least six specimens shall be selected from a homogenous batch.  
7.2 Test specimens 
The test specimens shall have the form of a cylinder, cube or prism (70 ± 5) mm or (50 ± 5) mm and shall 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 test specimens are to be dried to constant mass at a temperature of (70 ± 5) °C. Constant mass is 
reached when the difference between two successive weighings at an interval of (24 ± 2) h is not greater than 
0,1 % of the first of the two masses.  
The specimens shall be kept in a desiccator until room temperature (20 ± 5) °C is attained.  
8 Test procedure 
Weigh the specimens after drying (md) to an accuracy of 0,01 g. Place the specimens in the tank on the 
supports provided. Each specimen needs to be at least 15 mm from adjacent specimens. Then add tap water 
at (20 ± 10) °C up to half the height of the specimens (time t0). At time t0 + (60 ± 5) min add tap water until the 
level of the water reaches three-quarter of the height of the specimens.  
At time t0 + (120 ± 5) min add tap water until the specimens are completely immersed to a depth of (25 ± 5) 
mm of water.  
At time t0 + (48 ± 2) h the specimens are taken out of the water, quickly wiped with a damp cloth and then 
weighed within 1 min to an accuracy of 0.01 g (mi).  
Immerse the specimens again in water and continue the test. Every (24 ± 2) h the specimens are taken out of 
the water, quickly wiped with a damp cloth and then weighed within 1 min to an accuracy of 0.01 g.  
Note the successive masses of the specimens (mi).  DRS 549: 2023 
3                ©RSB 2023- All rights reserved 
 Continue the test up to constant mass of the specimens. Constant mass is reached when the difference 
between two successive weighing is not greater than 0,1 % of the first of the two masses.  
The result of the last weighing is the mass of the saturated specimen ( ms). 
9 Expression of results 
The water absorption at atmospheric pressure Ab of each specimen is calculated by the equation:  
𝐴௕=𝑚௦−𝑚ௗ
𝑚ௗ𝑥100 
The result shall be expressed as a percentage to the nearest 0.1 %. 
10 Test report 
The test report shall contain the following information:  
a) unique identification number of the report;  
b) the number, title and date of issue of this Rwanda  Standard,  
c) the name and address of the test laboratory and the address where the test was carried out if different 
from the test laboratory;  
d) the name and address of the client;  
e) it is the responsibility of the client to supply the following information:  
  the petrographic name of the stone;  
 the commercial name of the stone;  
 the country and region of extraction;  
 the name of the supplier;  
 the direction of any existing plane of anisotropy (if relevant to the test) to be clearly indicated on the 
sample or on each specimen by means of two parallel lines;  
 the name of the person or organisation which carried out the sampling;  
 the surface finish of the specimen (if relevant to the test);  
f) the date of delivery of the sample or of the specimens;   
©RSB 2023- All rights reserved                  4 
 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 water absorption at atmospheric pressure to the nearest 0.1 %;  
k) the arithmetic mean of the individual values of water absorption at atmospheric pressure expressed to the 
nearest 0.1 %;  
l) all deviations from the standard and their justification;  
m) remarks.  
The test report shall contain the signature(s) and role(s) of the responsible(s) for the testing and the date of 
issue of the report. It shall also state that the report shall not be partially reproduced without the written 
consent of the test laboratory. 
 
 
 DRS 549: 2023 
 
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