ICS 91.080.30   
 
Reference number  
DRS  211-3: 2010 
© RSB 2021  
  
 RWANDA 
STANDARD  DRS  
211-3  
 
First edition  
2010-03-18 
(Reaffirmed 2021 -mm-dd 
Mortar for masonry — Test method s —  
Part 3: Determination of consistence of 
fresh mortar (by flow table)  
   
DRS  211-3: 2010 
©RSB 2021  - 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  
 
 
 
 
 
 
 
 
© RSB 2021  
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 R SB. 
Requests for permission to reproduce this document should be addressed to : 
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E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw   DRS  211-3: 2010 
iii                ©RSB 2021  - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ...................  iv 
Introduction  ................................ ................................ ................................ ................................ ...............  vi 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  1 
4 Principle  ................................ ................................ ................................ ................................ ........  1 
5 Apparatus  ................................ ................................ ................................ ................................ ...... 1 
6 Sampling, preparation and storage of test samples  ................................ ................................ . 3 
7 Procedure  ................................ ................................ ................................ ................................ ...... 3 
8 Calculation and expression of results  ................................ ................................ .......................  4 
9 Test report  ................................ ................................ ................................ ................................ ..... 4 
Annex  A (normative)   Details of flow table  ................................ ................................ .............................  5 
A.1 General  ................................ ................................ ................................ ................................ ..........  5 
 DRS  211-3: 2010 
©RSB 2021  - All rights reserved                  iv 
 Foreword  
Rwanda Standard s are prepared  by 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 S tandards adop ted 
by technical  committ ees are ratified  by me mbers of RSB Board of Director s for publication and gazettment as 
Rwanda Standards.  
DRS  211-3 was prepared by Technical Committee RSB/TC 009, Civil engineering and b uilding materials . 
In the preparation of this standard, reference was made to the following standard s: 
1) BS EN 998 -1, Specification for mortar for masonry – Part 1: Rendering and plastering mortar with inorganic 
binding agents   
2) BS EN 998 -2, Specification for mortar for masonry – Part 2: Masonry mortar   
3) BS EN 1015 -2, Methods of test for mortar for masonry – Part 2: Bulk sampling of mortars and preparation 
of test mortars  
The assistance de rived from the above source is hereby acknowledged with thanks.  
CD 211  consists of the following p arts, under the general title Mortar for masonry  —Test methods : 
⎯ Part 1: Determination of particle size distribution (by sieve analysis)  
⎯ Part 2: Bulk sampling of mortars and preparation of test mortars  
⎯ Part 3: Determination of consistence of fresh mortar (by flow table)  
⎯ Part 4: Determination of consistence of fresh mortar (by plunger penetration)  
⎯ Part 5: Determination of flexural and compressive strength of hardened mortar  
⎯ Part 6: Determination of adhesive strength of hardened rendering and plastering mortars on substrates  
⎯ Part 7: Determination of water absorption coefficient due to capillary action of hardened mortar  
 
 
 DRS  211-3: 2010 
v                ©RSB 2021  - All rights reserved  
 Committee membership  
The following organizations were represented on the Technical Committee on Civil engineering and building 
materials  (RSB/TC 009)  in the preparation of this standard.  
CIMERWA   
Enabel   
EGC Ltd   
GECO Africa  
Mass Design Group  
Rwanda Housing Authority (RHA)  
Rwanda Inspectorate, Competition and Consumer Protection Authority (RICA)  
Standard Geotechnical Engineering and Construction Ltd (STAGECO  Ltd) 
SJEC Ltd  
University of Rwanda/College of Science and Technology (UR -CST)  
Rwanda  Standards Board  (RSB) – Secretariat  
  DRS  211-3: 2010 
©RSB 2021  - All rights reserved                  vi 
  
Introduction  
Consistence is a measure of the fluidity and/or wetness of the fresh mortar and gives a measure of the 
deformability of the fresh mortar when subjected to a certain type of stress. The consistence however is not 
directly associated with the manner in which  the fresh mortar handles when used by a craftsman. Normally 
there will be a linear correlation between flow value, measured in accordance with this test method, and the 
plunger penetration value measured in accordance with DRS 211 -4, for the same type of mortar with increasing 
water content, but the slope will differ with different types of mortars.  DRS  211-3: 2010 
1                ©RSB 2021  - All rights reserved  
 Mortar for masonry — Test method  — Part 3: Determination of 
consistence of fresh mortar (by flow table)   
1 Scope  
This Draft Rwanda Standard  provides a method for determining the consistence of freshly mixed mortars 
including those containing mineral binders and both normal weight and lightweight aggregates, which is by 
means of the flow value.  
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 edition  cited applies. For undated references, the 
latest edition of the referenced document (including any amendments)  applies.  
RS 108, Mortar for masonry — Specification   
RS 211-2, Mortar for masonry — Methods of test — Part 2: Sampling of mortars and preparation of test 
mortars    
3 Terms and definitions  
No terms and definitions are listed in this document . 
4 Principle  
The f low value is measured by the mean diameter of a test sample of the fresh mortar which has been placed 
on a defined flow table disc by means of a defined mould, and given a number of vertical impacts by raising the 
flow table and allowing it to fall freely through a given height.  
5 Apparatus  
5.1 A flow table ; as indicated on the figure 1 and described in Annex A, consisting of the following main 
parts:  
a) stand;  
b) rigid table, plate and disc;  
c) horizontal shaft and lifting cam; and  
d) lifting spindle.  
5.2 A truncated conical mould ; Made of stainless steel or brass, 60 mm ± 0.5 mm in height and with internal 
diameter of 100 mm ± 0.5 mm at the bottom and 70 mm ± 0.5 mm at the top. The inside surface and the edges  
©RSB 2021  - All rights reserved                  2 
 of the mould are smooth. The planes containing t he top and bottom edges are at right angles to its axis. The 
minimum thickness of the mould wall is 2.0 mm.  
5.3 A tamper ; Consisting of a rigid, non -absorptive rod of circular cross -section, approximately 40 mm in 
diameter and approximately 200 mm long. T he tamping face is flat and at right angles to the length of the 
tamper. The mass of the tamper is 0.250 kg ± 0.015 kg.  
5.4 Callipers ; Capable of measuring diameters up to 300 mm with an accuracy of 1 mm.  
5.5 Towel  
5.6 Palette knife  
  
DRS  211-3: 2010 
3                ©RSB 2021  - All rights reserved  
 Figure 1 — Flow table  
Key  
1 Stand  
2 Horizontal shaft  
3 Lifting spingle  
4 Truncated conical mould  
5 Disc  
6 Rigid table  
7 Lifting cam.  
6 Sampling, preparation and storage of test samples  
6.1 The fresh mortar for this test shall have a minimum volume of 1.5 Land shall be obtained by reduction of 
the bulk test sample (see RS 211 -2) using a sample divider or by quartering.  
6.2 Ready to use mortars (factory -made wet mortars which are retarded), a nd pre -batched air -lime/sand wet 
mortars when not gauged with hydraulic binders, shall be tested within their specified workable life.  
6.3 Mortars that are made from dry constituents and water shall be mixed in accordance with RS 211 -2 unless 
otherwise sp ecified.  
6.4 The length of the mixing period shall be measured from the moment all the constituents are introduced 
into the mixer.  
6.5 Before testing, the batch shall be gently stirred by hand using a trowel or palette knife in 5 – 10 sec to 
counteract a ny false setting etc., but without any additional mixing of the batch.  
6.6  Any deviation from the mixing procedure shall be noted.  
6.7  Two test samples shall be tested.  
7 Procedure  
7.1 Before each test, wipe the disc and the inner surface and edges of the mould (see 5.2) clean with a damp 
cloth and let it dry. If the table has not been used within the last 24 h, operate it for ten revolutions before use.  
7.2 Place the mould centrally on the disc of the flow table (see 5.1) and introduce the mortar in t wo layers, 
each layer being compacted by at least 10 short strokes of the tamper (see 5.3) to ensure uniform filling of the 
mould.  
7.3  During filling, hold the mould firmly on the disc, using one hand.   
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 7.4 Skim off the excess mortar with a palette knife  and wipe the free area of disc clean and dry, being 
especially careful to remove any water from around the bottom edge of the mould. After approximately 15 s, 
slowly raise the mould vertically and spread out the mortar on the disc by jolting the flow tabl e 15 times at a 
constant frequency of approximately one per second.  
7.5  Measure the diameter of the mortar in two directions at right angles to one another using calipers (see 
5.4).  
7.6  State the results in mm to the nearest mm.  
8 Calculation and expres sion of results  
8.1 Calculate the mean value of the two measurements. This mean value is the flow value for the test sample.  
8.2 If the individual flow values from the two test samples deviate from their mean use this mean value as the 
flow value of the mortar. If the two individual flow values deviate from their mean value by more than 10 %, 
repeat the test using further mortar from the reduced bulk test sample (see 6) and if the results deviate from the 
mean value by less than 10 % use the mean value fr om the repeat test as the flow value of the mortar. If the 
results differ by more than 10 % consider the measurements unsatisfactory and take fresh test samples from 
the bulk test sample or laboratory prepared mortar and repeat the test.  
9 Test report  
The test report shall include the following information:  
a) the place, date and time of taking the bulk test sample;  
b) the method used for taking the bulk test sample (if known) and the name of the organization that took it;  
c) the type, origin and designation of the mortar by reference to RS 108;  
d) preparation (mixing, casting) and storage (curing) conditions;  
e) the date and time of preparing test samples for test (i.e. date and time of any mixing, casting, moulding, or 
demoulding  procedure, if appropriate);  
f) the date and time of testing;  
g) test results (individual measurements and the flow values in mm for each test sample); and h) remarks, if 
any.  
NOTE  This is the sample taken from the bulk supply that is to be used for all of the tests in RS 211.  
 
 DRS  211-3: 2010 
5                ©RSB 2021  - All rights reserved  
 Annex  A 
(normative)  
 
Details of flow table  
A.1 General  
A.1.1  Details of the flow table defined in this Rwanda Standard are shown in Figure 1.  
A.1.2 The stand  for th e flow table shall be made of steel or cast iron. The flow table shall be mounted without 
any other support directly on a horizontal, non -sprung and non -plastic, stable base.  
NOTE  A concrete pedestal with a mass of more than 25 kg is suitable.  
A.1.3 The horizontal shaft with the mounted lifting cam when turned at a constant velocity shall raise the lifting 
spindle and the flow table by 10 mm/s ± 0.2 mm/s.  
A.1.4 The lifting cam shall be an even steady rising spiral constructed such that it will resume per manent contact 
with the lifting spindle from 120° after the impact has occurred and through the following 240° rotation up to the 
next impact.  
A.1.5 The vertical lifting spindle shall be fastened at top in the middle of a rigid table plate. Both of these shall 
be made of steel or cast iron. The lifting spindle shall be stabilised by bearings spaced minimum 60 mm vertical 
in the stand, the bearings having a tolerance in diameter of 0.05 mm - 0.1 mm.  
Note The contact faces of the lower end of the lifting sp indle and of the lifting cam should be constructed to ensure long 
term performance. A rotatable roller in the lower end of the lifting spindle is suitable.  
A.1.6 The edge of the lifting cam and the lower end of the lifting spindle may alternatively be har dened to a 
Brinell hardness of 500 kg/mm2.  
A.1.7 The rigid table plate shall carry a disc 300 mm ± 1 mm in diameter and 4 mm ± 0.1 mm in thickness 
centrally attached to the supporting table plate by means of suitable fixing devices uniformly spaced along the 
periphery of the disc.   
A.1.8 The disc shall be made of a material resistant to corrosion by mortar and with a smooth surface of 
maximum 0.005 mm coarseness, the surface cleaned and lightly lubricated with very low viscosity non -resin 
mineral oil prior to testing.  
A.1.9 The upper surface of the disc  shall have engraved a circle of 100 mm diameter and 0.5 mm deep to 
facilitate centring of the mould. The disc shall be kept horizontal during the test.  
A.1.10 The total mass (M) of the movable parts of the table, i.e. lifting spindle, rigid table and cir cular disc, shall 
be 4.2 ≤ M ≤ 4.5 kg.   
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 A.1.11 The flow table shall not be constructed in any way which inhibits its rotation, however the manufacturing 
precision of the movable parts of the flow table shall be such that the rotation is restricted to less than one 
revolution per 15 jolts.  
A.1.12 The lifting spindle shall fall without hindrance. It shall be kept clean and lightly coated with very low 
viscosity non -resin mineral oil.  
A.1.13 At the lowest point, the lifting cam shall clear the end of the lif ting spindle such that the boss of the table 
plate firmly strikes the counter boss of the table stand. The boss and the counter -boss shall have contact on the 
total circular ring, both kept free of any adhering dust or moisture (water, oil etc.).              
               
NOTE   A 45  ° slope with a width of 1 mm at the inner diameter of the counter -boss, and an enlargement of the 
diameter of the upper bearing of 1 mm with a depth of 3 mm is suitable.  
 DRS  211-3: 2010 
 
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