KENYA STANDARD       KS 2834:  2018 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
Concrete kerb units  Requirements and test 
methods  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ©KEBS 20 18        First Edition 20 18. 
 
 
 
 
 
 
  ii TECHNICAL COMMITTEE REPRESENTATION  
 
The following organizations were represented on the Technical Committee:  
 
 1. Architectural Association of  Kenya  
2. Bamburi Cement  
3. CHRYSO Eastern Africa Limited  
4. Concrete Products (K)Ltd  
5. Consumer Information Network  
6. Howards Humphreys  East Africa LTD  
7. Institute of quantity surveyors of Kenya  
8. Kenya Industrial Research and Development Institute (KIRDI  
9. Kenya Institute of Highways and Building Technology (KIHBT)  
10. Ministry of Transport, Infrastructure, Housing an d Urban Development.  
11. National Environment Management Authority  
12. National Housing Corporation  
13. Technical University of Kenya  
14. University of Nairobi  
15. Kenya Bureau of Standards — Secretariat  
 
 
 
 
 
 
 
 
 
REVISION OF KENYA STANDARDS  
 
In order to keep abreast of progress in industry, Kenya Standards shall be regularly reviewed. Suggestions 
for improvements to published standards, addressed to the Managing Director, Kenya Bureau of Standards, 
are welcome.  
 
 
 
 
 
 
 
 
 
© Kenya Bureau of Standards, 2018 
 
Copyright: Users are reminded that by virtue of section 6 of the Copyright Act, Cap. 130 of the Laws of Kenya, copyright subsists in all 
Kenya Standards and except as provided under section 7 of this Act, no Kenya Standard produced by Kenya Bureau of Stand ards may 
be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing from the 
Managing Director . 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
  iii    KENYA STANDARD        KS 2834 : 2018 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Concrete kerb units  Requirements and test 
methods  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
KENYA BUREAU OF STANDARDS (KEBS)  
 
Head Office:  P.O. Box 54974, Nairobi -00200, Tel.: (+254 020) 605490, 602350, Fax: (+254 020) 604031  
E-Mail: info@kebs.org,  Web:http://www.kebs.org   
 
Coast Region     Lake Region          Rift Valley Region  
P.O. Box 99376, Mombasa -80100   P.O. Box 2949, Kisumu -40100        P.O. Box 2138, Nakuru -20100  
Tel.: (+254 041) 229563, 230939/40                Tel.: (+254 057) 23549, 22396        Tel.: (+254 051) 210553, 210555  
Fax: (+254 0 41) 229448    Fax: (+254 057) 21814   iv  
 
 
Foreword  
 
This Kenya Standard was prepared by the Concrete and Concrete Products Technical Committee under the 
guidance of the Standards Projects Committee and it is in accordance with the procedures of the Kenya 
Bureau of Standards.  
  
 
During the preparation of this standard, reference was made to the following publications:  
 
BS EN 1340:2003 Concrete kerb units  Requirements and test methods  
 
Acknowledgement is hereby made for the assistance derived from these so urces.   
  5     
KENYA STANDARD       KS 2834  :2018 
 
Concrete paving Kerbs  — Requirements and test methods  
 
1. Scope  
This Standard specifies materials, properties, requirements and test methods for unreinforced, cement bound 
precast concrete kerb units, channels and complementary fittings, that are for use in trafficked paved areas and 
roof coverings.  
 
The units are used  to fulfil one or more of the following:  
 
Separation, physical or visual delineation, the provision of drainage or the containment of paved areas or other 
surfacing.  
 
In case of regular use of studded tyres, additional requirements are sometimes needed.  
This standard provides for the product marking and the evaluation of conformity of the product to this European 
standard.  
 
Apart from the tolerances, this standard does not include requirements for cross -sections, shapes and dimensions.  
This standard does not deal with the tactility or visibility of kerbs.  
 
2.  Normative references  
This Standard incorporates by dated and undated references, provisions from other publications. These 
normative references are cited at the appropriate places in the text, and the publications are listed hereafter. 
For dated references subsequent amendments to or revisions of any of these publications apply to this Standard 
only when incorporated in it by amendment or revision. For undated references, the latest edition of the 
publication referred to applies (including amendments).  
 
KS EAS 148 -1: 2017  Cement - Test methods Part 1: Determination of strength.  
  
KS EAS 148 -2: 2017  Cement - Test methods Part 2: Chemical analysis.  
 
KS EAS 148 -3: 2017  Cement - Test methods Part 3: Determi nation of setting times and soundness.  
 
KS EAS 148 -4: 2017 Cement - Test methods Part 4: Quantitative determination of constituents.  
  
KS EAS 148 -5: 2017 Cement - Test methods Part 5: Pozzolanicity test for pozzolanic cements.  
  
KS EAS 148 -6: 2017 Cement  - Test methods Part 6: Determination of fineness  
 
KS EAS 148 -7: 2017 Cement - Test methods Part 7: Methods of taking and preparing samples.  
 
KS EAS 148 -8: 2017 Cement - Test methods Part 8: Heat of hydration - Solution method.  
  
KS 2770  Admixtures for concrete, mortar and grout  Part 1  Admixtures for concrete, mortar and grout —
Common requirements  
KS 2770 Part 2  Concrete admixtures — Definitions, requirements, conformity, marking and labelling  
EN 10083 -2, Quenched and tempered steels — Part 2: Technical delivery conditions for unalloyed quality 
steels.  
 
EN 13369, Common rules for precast concrete products.  
 
ISO 4288, Geometric product specification (GPS) - Surface texture - Profile method: Rules and procedures for 
the assessment of surface texture (ISO 4288:1996).  
 
ISO 6506 -1, Metallic materials - Brinell hardness test - Part 1: Test method.  
 
1S0 6506 -2, Metallic materials - Brinell hardness test - Part 2: Verification and calibration of testing 
machines.   6  
ISO 6506 -3, Metallic materials - Brinell hardness test - Part 3: Calibration of reference blocks.  
 
ISO 48, Rubber, vulcanised or thermoplastic — Determination of hardness (hardness between 10 
IRHD and 100 IRHD).  
 
ISO 4662, Rubber — Determination of rebound resilience of vulcanizates.  
 
ISO 7619, Rubber— Determination of indentation hardness by means of pocket hardness meters.  
 
ISO 7873, Control charts for arithmetic average with warning limits.  
 
ISO 7966, Acceptance control charts.  
 
ISO 8486 -1:1996, Bond abrasives — Determination and designation of grainsize distribution — 
Macrogrits F4 to F220.  
 
3.  Terms and definitions  
For the purposes of this Standard, the following terms and definitions apply.  
 
3.1.  
concrete curb unit  
precast concrete unit, individual or in combination with other units, intended to separate surfaces of the 
same or of different levels to provide physical or visual delineation or containment and separation between 
reas submitted to different kinds of traffic  
 
physical or visual delineation or containment;  
 
individually or in combination with other kerbs, drainage channels;  
 
separation between surfaces submitted to different kinds of traffic.  
3.2.  
complementary fitting  
unit, sometimes a part of a kerb, channel etc, which is used as a transition piece for changes in 
direction, shape or height or a small piece to complete a line  
 
3.3.  
overall length  
length of a kerb excluding any interlocking features or spacers  
 
3.4.  
height  
distance  between the bed face and the top of the kerb  
 
3.5.  
bed face  
lower surface in contact with the ground after laying  
 
3.6.  
face 
surface intended by the manufacturer to be seen when laid and in use  
 
3.7.  
facing layer  
layer of concrete on the face, or part of a face, of d ifferent materials and/or properties to the main 
body or backing layer  
 
NOTE: To be distinguished from wipe, being a fine cement mortar or slurry applied to the surface of the kerb.  
 
3.8.  
draw  
intended  angle of the side face from the vertical plane over the full height of a kerb as shown in 
Figure 1  
 
3.9.  
chamfer   
  7    bevelled arris, as shown in Figure 1  
 
 
 
 
Key 
1 Chamfer  2 Height  a Draw  
 
Figure 1 — Example of chamfer and draw  
 
 
3.10.   
arris  
part of a kerb where two faces meet. It can be bevelled, rounded, chamfered, radiussed or splayed  
 
 
3.11.   
work dimension  
dimension of a kerb specified for its manufacture to which the actual dimension should conform within 
specified permissible deviations  
 
3.12.   
secondary  processing  
manufacturing process to texture the whole kerb or any surface, carried out after basic manufacture  
before or after hardening  
 
3.13.   
actual dimension  
dimension of a kerb as measured  
 
3.14.   
chased side face  
side face of a concrete kerb, having a recessed  profile  
 
3.15.   
skid resistance  
ability to resist relative movement between a vehicle tyre and the trafficked concrete kerb surface  
 
 8 3.16.   
slip resistance  
ability to resist relative movement between a pedestrian foot and the trafficked concrete kerb  surface  
 
3.17.  reference line  
kerb or channel line to which the unit is intended to be laid  
 
3.18.   
traffic face  
face of a kerb intended by the manufacturer to be above a road surface and 
which provides containment of traffic  
 
3.19.   
wipe  
fine cement mortar or slurry applied to the surface of the units  
 
4.  Requirements for materials  
 
4.1. General  
Only materials with suitability established in terms of their properties and performance shall be used in the 
manufacture of concrete kerb units.The  suitability requirements of the materials used shall be given in the 
manufacturer's production control documentation.  
 
Where, by conformity with relevant specifications, the properties and performance of materials have been 
demonstrated, further testing n eed not be performed.  
 
A reference scheme for materials inspection is given in annex A.  
 
4.2.  Asbestos  
Asbestos, or materials containing asbestos, shall not be used.  
 
5. Requirements for products  
  
5.1.  General  
The performance requirements of concrete kerb  units are defined by classes which have associated marking 
designations.  
 
Kerbs may be produced with a single concrete throughout or with different facing and backing layers.  
When kerbs  are produced with a facing layer this layer shall have a minimum thickness of 4 mm over that area 
claimed by the manufacturer to be faced, when measured in accordance with annex C. Isolated particles of 
aggregate protruding into the facing layer shall be ignored. The facing layer shall be an integral part of the 
kerb.  
 
A bevelled arris exceeding 2 mm shall be described as chamfered. Its dimensions shall be declared by the 
manufacturer.  
 
Kerbs  may be produced with functional and/or decorative profiles, which shall not be included in the work 
dimensions of a kerb.  
The surface of kerbs may be textured, secondary processed or treated chemically; these finishes or 
treatments shall be described and declared by the manufacturer.  
 
5.2.  Shape and dimensions  
 
5.2.1.  General  
All references to dimensions in this subclause are to work dimensions.  
 
The conformity criteria corresponding to each requirement taken separately are given in 6.3.8.1. The 
dimensions and deviations shall be measured according to annex C.  
 
National standards may specify kerb cross -sections and lengths.  
 
NOTE The size of the space allocated to the kerb should include an allowance for joints and deviations.  
 
5.2.2.  Work dimensions  
The work dimensions shall be stated by the manufacturer.  
  
  9    NOTE The recommended length of a straight kerb including joint is 1 000 mm.  
 
5.2.3.  Unit geometry  
 
5.2.3.1.  End treatment  
Kerbs  may be produced with plain ends or with end features to facilitate interlocking 
or laying. These features shall be declared by the manufacturer.  
Figures 2, 3 and 4 show examples.  
 
 
 
 
 
Key  
Y≤X-3mm and Z y ≤ Z x- 3mm  
X minimum : ≥1/5 b and ≥20 mm  
X maximum : ≤1/3 b and ≤ 70 mm  
Zy maximum : Y/2  
Tolerance on X and Z x-1, + 2 mm  
Tolerance on Y and Z y -2, +1 mm  
L Length of kerb unit  
W Width of kerb unit  
Figure 2 — Example of interlocking feature; requirement of dimensions and 
permissible deviations deviations
 
 
Key 
L - Length  
a and b — Dimensions of chase 
c— Dimension of draw  
Figure 3 — Example of dimensions of chase and draw  
 10  
Key 
H — Height of kerb unit  
h — Height of recess or 
cut out W — Width of 
kerb unit  
L — Length of kerb unit  
I — Length of recess or cut -out 
Figure 4 — Example of a recess or cut -out on the bottom end of a kerb  
 
5.2.3.2.  Radiussed kerbs  
Radiussed kerbs shall be described as convex or concave. The description shall refer to 
the reference line. The radius of a kerb  and its overall length shall be measured to and along 
its reference line. (see Figure 5).  
 
The preferred radii of the kerb are 0 .5; 1; 2; 3; 4; 5; 6; 8; 10 and 15 m. The recommended 
length is 780 mm. National standards may specify other radii and length.  
 
 
 
 
 
 
 
 
 Key 
1 Kerb  4 Radius  
2 Carriageway  5 Channel  
3 Length  
Figure 5 — Examples of radiussed kerbs, a) concave and b) convex  
 
5.2.3.3.  Permissible deviations  
The values for the permissible deviations on the manufacturer's  declared work dimensions are as given 
below:  
 
Length:  ± 1 % to th e nearest millimetre with a mini mum of 4 mm, not exceeding 10 mm.  
 
Other dimensions, except radius:  
 
for faces:  ± 3 % to the nearest millimetre with a minimum of 3 mm, not exceeding 5 mm.  
 
for other parts:  ± 5 % to the nearest millimetre with a minimum of 3 mm, not exceeding 10 mm.  
 
The difference between any two measurements of a single dimension of a single kerb shall be  ≤ 5 mm.  
 
For faces described as flat and edges described as straight,  the permissible deviations on flatness and 
straightness are given in Table 1.  
 
 
 
 
 
1 
  
  11    Table 1 — Permissible deviations of flatness and straightness  
Length of gauge  Permissible deviation of flatness and  
straightness  
mm mm 
300 ± 1.5  
400 ± 2.0  
500 ± 2.5  
800 ± 4.0  
5.3.  Physical and mechanical properties  
 
5.3.1.  General  
The kerbs shall conform to the following requirements at the time they are declared suitable for use by 
the manufacturer.  
 
When complementary fittings or kerbs , because of their geometry, cannot be tested according to this 
standard, they are considered to conform to this standard, provided they have at least the same concrete 
quality as kerbs complying  this standard.  
 
5.3.2.  Weathering resistance  
 
5.3.2.1.  Test methods  
The we athering resistance is determined by test according to Annex  E for water absorption and to the 
conformity criteria of 6.3.8.2.  
 
5.3.2.2.  Performances and classes  
The kerbs shall conform to the requirements in Tables 2.1 or 2.2.  
 
Recommendations as to the class(es ) of weathering resistance required to ensure durability for that 
country, for the uses for which the product is put on the market, may be made at a national level.  
 
Table 2.1 — Water absorption  
Class  Marking  Water absorption  
% by mass  
1 A no performance  measured  
2 B ≤ 6 
 
 
5.3.3.  Bending strength  
 
5.3.3.1.   Test method  
The characteristic bending strength shall be determined by testing according to annex E and to the 
conformity criteria given in 6.3.8.3. 12 5.3.3.2.  Performance and classes  
The characteristic bending strength shall not be less than the value corresponding to the class in 
Table 3.  
 
None of the individual results shall be less than the corresponding minimum bending strength in 
Table 3. When kerbs, due to their geometry, cannot be tested according to this standard they shall be 
considered to be in the same class as tested kerbs provided they have at least the same concrete 
strength.  
Table 3 — Bending strength classes  
Class  Marking  Characteristic bending strength  
MPa Minimum bending strength  
MPa 
1 S 3.5 2.8 
2 T 5.0 4.0 
3 U 6.0 4.8 
 
5.3.3.3.    Durability of strength  
Under normal exposure conditions of use precast concrete kerbs will continue to provide satisfactory 
strength during the working life of the product, provided they conform to 5.3.3.2 and are subject to 
normal maintenance.  
 
5.3.4.   Abrasion resistance  
 
5.3.4.1.  Test method  
Abrasion resistance is determined by the Wide Wheel Abrasion test (see annex F), or as an 
alternative by the Bohme test (see annex G). The Wide Wheel Abrasion test is the reference test.  
 
5.3.4.2.  Performance and classes  
 
Requirements for abrasion resistance are given in Table 4.  
 
No individual result shall be greater than the required value.  
 
Table 4 — Abrasion resistance classes  
Class  Marking  Requirement  
  Measured in accordance with  
the test method described in  
annex G  Alternatively measured in accordance  
with the test method described in  
annex H  
1 F No performance measured  No performance measured  
3 H ≤23 mm  ≤20 000 mm3/5 000 mm2 
4 I ≤20 mm  ≤18 000 mm3/5 000 mm2 
 
5.3.5.  Slip/skid resistance  
 
5.3.5.1.  Conditions  
Concrete kerbs have satisfactory slip/skid resistance provided that their whole upper surface has 
not been ground and/or polished to produce a very smooth surface.  
 
5.3.5.2.  Test method  
If in an exceptional case a value for slip/skid resistance is required, the test method as described 
in annex H shall be used and the minimum slip/skid resistance value shall be declared.  
 
If the surface of a kerb  contains ridges, grooves or other surface features which prevent testing by the 
pendulum friction equipment, the product is deemed to satisfy the requirements of this standard 
without testing. Where the kerb is too small to provide a test area, the manufa cturer shall test a larger 
kerb having the same surface finish as the kerb in question.  
 
NOTE  The slip/skid resistance value relates to kerbs as manufactured and helps to ensure adequate slip/skid resistance on installation.  
 
5.3.5.3.   Durability of slip/skid resistance  
 
Under normal conditions of use precast concrete kerbs provide satisfactory slip/skid resistance 
during the working life of the product, provided they are subjected to normal maintenance and unless a 
major proportion of aggregates which polish excessively have been exposed on the upper face.  
  
  13     
5.3.6.  Fire performance  
 
5.3.6.1.  Reaction to fire  
Concrete kerb units are Class Al reaction to fire without testing1). 
 
5.3.6.2.  External fire performance  
Concrete kerbs  used as roof covering are deemed to satisfy the requirements for external fire 
performance without the need for testing2). 
 
5.3.7.  Thermal conductivity  
If concrete kerbs are intended to contribute to the thermal performance of an element, then the 
manufacturer shall declare the thermal conductivity using design data from EN 13369.  
 
5.4. Visual aspects  
 
5.4.1.  Appearance  
The face of the kerb shall not exhibit defects such as cracking or flaking when examined in 
accordance with annex I. 
 
In the case of two -layer kerbs  examined in accordance with annex I, there shall be no delamination (i.e. 
separation) between the layers.  
 
N O T E :  When efflorescence occurs it is not deleterious to the performance of the kerbs in use and is not considered significant.  
 
5.4.2.  Texture  
In the case of kerbs manufactured with a special surface texture, this texture shall be described by the 
manufacturer.  
If examined in accordance with annex I, compliance shall be established if there are no significant differences 
in texture to any samples  supplied by the manufacturer and approved by the purchaser.  
 
N O T E :   Variations in the texture consistency of the kerbs can be caused by unavoidable variations in the  properties of the raw 
materials and by variations in hardening and are not considered significant.  
 
5.4.3.  Colour  
Colours may be provided in a facing layer or throughout the unit at the manufacturer's discretion.  
 
If examined in accordance with annex I, compliance shall be established if there are no significant differences 
in colour  to any samples supplied by the manufacturer and approved by the purchaser.  
 
N O T E : Variations in the colour consistency of the kerbs can be caused by unavoidable variations in the shade and properties of the raw materials and by variations in hardening an d are not considered significant.  
 
6.  Evaluation of conformity  
6.1. General  
For the purpose of testing, the manufacturer may group products into families, where it is considered that the 
value of a selected property is common to all products within that family. Such families are:  
 
1) strength family: kerbs manufactured using the same type of materials and production methods, 
irrespective of dimensions and colours;  
 
2) surface family: kerbs with face mixes having the same main aggregate used in the mix (e.g. natural 
river gravel, crushed granite, porphyr, basalt or limestone) and the same surface treatment of the finished 
product, irrespective  of dimensions and colours.  
 
6.1.1.  Demonstration of conformity  
Compliance of the product with the requirements of this standard and with the declared values (levels or 
classes) for the product properties shall be demonstrated by carrying out both:  
 
type testing of the product (see 6.2);  
 
factory  production control (see 6.3), including product testing.  
 
6.1.2.   Assessment of conformity  
In addition, compliance of the product with this standard may be assessed:  
either  by a third party inspecting the manufacturer's type testing and factory production control procedures;   14  
or by acceptance testing of a consignment at delivery (e.g. in the case of dispute, see annex B).  
 
6.2. Type testing of the product  
 
6.2.1.  Initial type testing  
Initial type testing shall be performed to demonstrate conformity with this standard at the beginning of the 
manufacture of a new product type or a family of product types or setting up a new production line 
to confirm that the achieved properties of the p roduct meet the requirements of this standard and the 
values declared for it by the manufacturer.  
 
Where the product has previously been tested according to this standard, (same product, same 
characteristics, same or more demanding test method and sampling procedures) the result may be 
used to satisfy initial type testing.  
 
6.2.2.  Further type testing  
Whenever a change occurs in the raw materials, the proportions used or the production equipment or 
process, which would change significantly some or all of the properties of the finished product, the 
type tests shall be repeated for the selected property or properties.  
 
 NOTE  Examples of major changes:  
1) change from natural river gravel to crushed rock ag gregates or change of cement type or class;  
 
2) partial substitution of cement by additions.  
 
For abrasion and weathering resistance, type testing shall be repeated periodically with the 
frequency given in Table 5 even when no change occurs.  
 
Table 5 — Periodically repeated type testing  
Property  Frequency  
Abrasion (only classes 3 and 4)  Once per year per surface family  
Weathering resistance (only class 3)  Once per year per surface family') 
1) If for a surface family the result of a type test (mass loss) is lower than 50 % of the required value 
the test frequency may be reduced to once per two years. 
If for a surface family, routine water absorption testing at the frequency for class 2 products  
(see 6.3.8.2.) is carried out to demonstrate consistency with kerbs submitted to freeze/thaw testing, 
the required test frequency may be reduced to once per two years.  
If both conditions are met, the test frequency may be reduced to once per four years.  
 
6.2.3.  Sampling, testing and compliance criteria  
The number of kerbs to be tested shall be in accordance with Table 6 for the selected property.  
 
 
Table 6 — Sampling plan and conformity criteria for initial and further type testing  
 
Property  Requirements  Testing  method  Number of kerbs  Conformity criteria  
Visual aspects  5.4 Annex J 8 1) No kerb shall 
show cracking, 
flaking or 
delamination 2) 
Thickness 
of facing 
layer  5.1 C.6 8 Each kerb shall meet 
the requirements  
Shape 
and 
dimension
s 5.2 Annex C 2) 8 1) Each kerb shall meet 
the requirements for 
the declared class   
  15    Bending strength  5.3.2 - Table 3  Annex F 8 No kerb shall have 
a bending strength 
less than the 
characteristic value 
for the declared 
class  
Abrasion 
resistance (only 
classes 3 and 4)  5.3.3  Annex F or G 3 Each kerb shall meet 
the requirements for 
the declared class  
Slip/skid  resistance  
(only where tested)  5.3.4  Annex I 5 The mean of the 
five kerbs shall be 
declared  
Weatherin g 
resistance  
 
- class2   
 
 
5.3.1   
 
 
Annex  E   
 
 
 
Annex D    
 
 
3 
 
 
 
3  
 
 
No kerb shall have 
a water absorption  
of greater than 6% 
by mass  
 
The mean of the 
three kerbs shall 
not be greater thn 
1.0 kg/m2 with no 
individual result 
greater than 1.5 
kg/m2 
1) These kerbs may be used for subsequent tests.  
2) C.6 only applies for kerbs with a facing layer.  
 
The type tests shall be carried out in accordance with the reference test methods called up in this 
standard.  
 
Type testing is normally carried out with the manufacturer's test 
equipment.  
 
The test results shall be recorded.  
 
6.3. Factory production control  
 
6.3.1.  General  
The manufacturer shall establish, document and maintain a factory production control system to 
ensure that the products placed on the market will conform with the specified or declared values.  
The factory production control system shall consist of procedures, regular inspection and tests and the 
utilisation of the results to control raw and other incoming materials, equipment, the production 
process and the product.  
An example of a suitable insp ection scheme for factory production control is given in annex 
A. The results of inspections requiring action and the results of tests shall be recorded.  
The action to be taken when control values or criteria are not met shall be given.  
 
6.3.2.  Equipment  
All weighing, measuring and testing equipment shall be calibrated and regularly inspected according 
to the documented procedures, frequencies and criteria.  
An inspection scheme for equipment is given in A.1.  
 
6.3.3.  Raw and other incoming materials  
The specifications of all incoming materials shall be 
documented.   16  
An inspection scheme for raw materials is given in A.2.  
 
6.3.4.  Production process  
The relevant features of the plant and production process shall be defined giving the frequency of the 
inspectio n checks and tests, together with the criteria required both on equipment and on work in 
progress.  
 
An inspection scheme for the production process is given in A.3.  
 
  
6.3.5.  Product testing  
A sampling and testing plan of products shall be prepared and 
implemented. The sample shall be representative of production.  
 
The tests shall be carried out in accordance with the methods called up in this standard or by applying 
alternative test methods w ith a proven correlation to the standard methods.  
 
When complementary fittings or kerbs, because of their geometry, cannot be tested according to this 
standard, they are considered to conform to this standard, provided they have at least the same 
concrete quality as kerbs conforming with this standard.  
 
The results of testing shall meet the specified conformity criteria (see 6.3.8) and be 
recorded. An example of an inspection scheme for product testing is given in A.4.1.  
 
 
Switching rules for product testin g are given in A.5.  
6.3.6.  Marking, storage and delivery of products  
The marking, storage and delivery control, together with procedures for dealing with non -conforming 
products (see 6.3.7) shall be documented.  
 
Products may be released before the final results of factory production control testing are received, if 
they are subject to a positive recall procedure.  
 
An example of an inspection scheme for marking, storage and delivery is given in A.4.2.  
 
6.3.7.  Non-conforming products  
If the results of the tests on a product are unsatisfactory, the manufacturer shall take the necessary 
steps in order to rectify the shortcoming.  
 
Products which do not conform to the requirements shall be set aside and marked 
accordingly. If any non -conformity of the product is established after delivery, the customer 
shall be notified.  
 
6.3.8.  Product conformity criteria  
When the conformity criteria in this clause may be considered either by attributes or variables, the 
method applied shall be a t the manufacturer's discretion.  
 
6.3.8.1.   Shape and dimensions  
A. Attributes  
The conformity of the production with 5.2 shall be assessed for each production line per one to four 
production days (see sampling according to A.4.1.3). Each of the requirements in 5.2 shall be considered 
separately.  
 
a)If the sample consists of less than eight kerbs (see switching rules in A.5) and each of the 
requirements in 5.2 are complied with by all of the kerbs, then the sample and the corresponding 
production shall be accepted. If not, this sample shall be increased to eight kerbs and the 
procedure given in b) shall apply.  
 
b) If the sample consists of eight kerbs and not more than one of the kerbs  does not conform to 
any one of the requirements in 5.2 considered separately, the sample and the 
corresponding production shall be accepted. If not, this sample shall be increased to 16 units 
and the procedure given in c) shall be applied.  
 
If the sample and the corresponding production are not accepted, 6.3.7 applies.   
  17     
c) If the sample consists of 16 kerbs and not more than two of the kerbs do not conform to any one of the 
requirements in 5.2 considered separately,  the sample and the corresponding production shall be 
accepted. If more than two of the kerbs do not conform to any one of the requirements considered 
separately, the sample and the corresponding production are not accepted and 6.3.7 applies.  
 
B. Variables  
When the standard deviation of a production line is known and regularly checked, the compliance of the 
production with 5.2 shall be assessed for each production line per day or consecutive production days not 
exceeding five (see sampling according to A.4.1.3). Each of the requirements in 5.2 shall be considered 
separately.  
 
The conformity is assessed on a 10 % fractile.  
 
The acceptability of the samples considered shall be checked using a control chart conforming to either 
with ISO 7966 or ISO 7873 and taking into account 5.2, provided the probability of acceptance is 
equivalent to that resulting from assessment by attributes.  
 
6.3.8.2.  Weathering resistance (class 2 - water absorption)  
The conformity of the production with 5.3.2 (class 2) shall be assessed for each family and for each five 
production days, or more according to the switching rules (see sampling according to A .4.1.6)  
 
a) If the sample consists of three or six kerbs (see switching rules in A.5) and the requirements 
in 5.3.2 (class 2) are complied with, the sample and the corresponding production shall be 
accepted. If not, this sample shall be increased to nine kerbs and the procedure given in b) shall 
apply.  
 
b) If the sample consists of nine kerbs and the sample complies with the requirements in 
5.3.2 (class 2), the sample and the corresponding production shall be accepted. If not, the 
sample and the corresponding  production are not accepted and 6.3.7 applies.  
 
6.3.8.3.   Bending strength  
A. Attributes  
The conformity of the production with 5.3.3 shall be assessed for each production line per one to four 
production days (see sampling according to A.4.1.4).  
 
a. If the sample consists of eight kerbs or fewer (see switching rules A.5) and the strength T of 
each of the kerbs is not lower than the characteristic value of Table 3 for the declared class, the 
sample and the corresponding production shall be accepted. If  not, this sample shall be increased 
to 16 kerbs and the procedure given in b) shall apply.  
 
b. If the sample consists of 16 kerbs and the strength T of not more than one of the kerbs is lower 
than the characteristic value of Table 3 for the declared class, but not lower than the minimum 
value of Table 3 for the declared class, the sample and the corresponding production shall be 
accepted. If not, the sample and the corresponding production are not a ccepted and 6.3.7 applies.  
 
B. Variables  
When the standard deviation for a production line is known and regularly checked, the conformity of the 
production with 5.3.3 shall be assessed for each production line per production day or consecutive 
production d ays not exceeding five (see sampling according to A.4.1.4).  
 
The compliance is assessed on a 5 % fractile.  
 
The acceptability of the samples considered shall be checked using a control chart conforming either to 
ISO 7966 or to ISO 7873 and taking into account 5.3.3, provided the probability of acceptance is 
equivalent to that resulting from assessment by attributes (see annex K).  
 
If the sample and the corresponding production are not accepted, 6.3.7 applies.  
  
6.3.8.4.   Visual aspects  
The conformity of the production with 5.4 shall be assessed in case of doubt (see sampling according to 
A.4.1.2). The sample tested shall satisfy the requirements of the standard. If not, the sample and the 
corresponding production are not accepted and 6.3.7 applies.   18 ► EN 1340:2003 (E)  
25  
7. Marking  
 
1: On the delivery note or on the invoice or on 
the manufacturer's declaration.  
 
2:  On 0.5 % of the units with a minimum of 
one marking per package or on the packaging 
itself if not reused.  
 
Classes and  their identification:  
 
Requirement  Marking  
weathering resistance  A, B or D  
 
abrasion resistance  F, H or I  
 
I concrete bending strength S, T or U  
 
Where ZA.3 covers the same information as this clause 7, 
the requirements of this clause are met for CE marked 
products.  
 
8.  Test report  
The following particulars shall be supplied in the test report 
(other than for tests for factory production control):  
 
1) the name of the organization  carrying out the test;  
 
2) the name of the person carrying out the test;  
 
3) the date of the test;  
 
4) the name of the source providing the sample;  
 
5) the sample reference including the date of 
production;  
 
6) the name of the person taking the sample;  
 
7) the relevant KS number and annex;  
 
8) the name of the test;  
 
9) the test result;  
 
10) any pertinent remarks about the sample or test result.  
 
  19    Annex A  
(informative)  
Inspection schemes  
A.1 Equipment inspection  
Subject  Aim Method  Frequency  
A.1.1   Testing and measuring eauipment  
All testing  and 
measuring  
equipment  Correct  functioning  
and accuracy  Where  applicable,  calibrating  
against equipment which has been 
calibrated traceable to national 
standards and is used exclusively 
for this purpose except as indicated 
in the test method.  On (re)installation,  
after major  repair or  
once per year  
A .1.2 
 Storage and Production equipment  
 Storage of 
materials  Absence of 
contamination  Visual inspection or other 
appropriate method  - On installation 
- Weekly  
2 Weighing or 
volumetric 
batching 
equipment  Correct functioning  Visual Inspection  Daily 
3 Kerb 
manufacturer's 
declared 
accuracy  Calibrating against equipment 
which   has been calibrated  
to national standards and is used 
exclusively for this purpose.  - On (re)installation 
- Weighing: once  
a year  
- Volumetric: twice a 
year 
- In case of doubt  
4 Mixers  Wear and 
correct 
functioning  Visual inspection  Weekly  
5 Moulds  Cleanliness 
and condition  Visual inspection  Daily  20 A.2 Materials inspection  
Subject  Aim 1 Method  I Frequency  
A.2.1 All materials  
1 All materials  To ascertain that the 
consignment is as 
ordered and from the 
correct source  Inspection  of delivery  
ticket and/or label on the  
package  showing  
compliance with the order  Each delivery  
A.2.2 Materials not submitted to an assessment of conformity before delivery') 
1 Cement  and 
other  
cementitious 
materials  Conformity with kerb 
manufacturer's 
requirements  KS EAS 148  Each delivery  
2 Aggregates  Conformity with kerb 
manufacturer's 
requirements  
For example:  
- Particle grading  
- Impurities or  
contamination  KS 95 Each delivery  
3 
Test by sieve analysis  
Appropriate test method  - First delivery 
from new source 
- In case of doubt 
- Once per week  
- First delivery  
from new source 
- In case of doubt  
4 Admixture  Conformity  with 
normal appearance  KS 2770  Each delivery  
5 Density  Kerb manufacturer's  
method  
6 Additions/ 
pigments  Conformity  with 
normal appearance  Visual inspection  Each delivery  
7 Density  Kerb manufacturer's  
method  
8 Water not taken 
from a Public  
distribution 
System  Conformity with kerb 
manufacturer's 
requirements  Testing according to 
standard  - First use of new source  
- water from open water 
course: three times a 
year, or more (depending 
on local conditions)  
- Other sources : once a 
year 
- In case of doubt  
9 
10 Recycled 
Water  Check for solid 
content and other 
contaminants  Visual  Weekly  
Kerb manufacturer's  
method  In case of doubt  
1) Materials not audited by the precast product manufacturer or by a third party acceptable to the 
manufacturer.  
  21    A.3 Production process inspection  
Subject  Aim Method  Frequency  
1 Mixture 
compositio
n Conformity with  
intended composition 
(weight or volumetric 
batched)  - Visual on weighing 
equipment - Checking against 
production process 
documents  
 
 Daily 
2 Conformity with intended 
mixture values (only 
volumetric batched)  Fresh concrete analysis  Monthly  
3 Fresh concrete  Correct mixing  Visual check  Daily for each mixer  
4 Production  Conformity with 
documented factory 
procedures  Checking actions against factory 
procedures  Daily 
 
A.4 Product inspection  
Subject  Aim I Method  I Frequency 1,2,3) 
A.4. Product testing  
1 Visual aspects  See 5.4  Visual check  Daily 
2 Annex J In case of doubt (sample of ten 
kerbs).  
3 Shape  and 
dimensions  See 5.2  Annex C  Eight units per production line per 
four production days  
4 Bending  
strength  See 5.3.3 - Table 3  Annex F Eight kerbs per strength family per 
production line per four production 
days irrespective of the size  
5 Thickness  of 
facing layer  See 5.1  Annex C  Eight kerbs per strength family per 
production line per four production 
days irrespective of the size  
6 Weathering 
resistance  (only  
class 2)  See 5.3.2  Annex E Once  per surface family  per five  
production days  
A.4.2 Marking. storage. delivery  
1 Marking  Marking  of product  
according to clause 7  Visual check  Daily 
2 Storage  Segregation  of non- 
conforming product  Visual check  Daily 
3 Delivery  Correct  delivery  age, 
loading  and loading  
documents  Visual check  Daily 
1) Type testing according to 6.2 of this standard not included.  
2) The switching rules apply.  
3) See 6.1.   22 A.5 Switching rules  
Mil Normal inspection  
The rate of sampling should be in accordance with A.4.1.  
A.5.2 Normal to reduced inspection  
Reduced inspection corresponds to half the rate of normal inspection'}. It should be used where normal 
inspection is effective and the preceding 10 successive samples have been accepted.  
 
A supplementary reduced inspection is allowed if the same conditions as above are satisfied under 
reduced inspection. This supplementary r educed inspection should correspond to half the rate of the 
reduced inspection.  
A.5.3 Reduced to normal inspection  
When reduced inspection or supplementary reduced inspection is in effect, normal inspection should be 
reinstated if any of the following occurs:  
 
- a sample is not accepted;  
 
- or the production becomes irregular or delayed;  
 
- or other conditions warrant that normal inspection should be instituted.  
A.5.4 Tightened inspection  
Tightened inspection requires the number of kerbs  in the sample to be doubled.  
It should be used if during normal inspection two out of five successive samples fail.  
A.5.5 Tightened to normal inspection  
Tightened inspection should continue until five successive samples are accepted. 
Then normal inspection may be resumed.  
A.5.6 Stowed production  
If production remains on tightened inspection for ten successive samples the production line should be 
deemed to be out of control and stopped. The production system should be reviewed and any necessary 
changes made.  
 
Having corrected the production system, production should start again on tightened inspection.  
1) If the number of kerbs in the sample is even, the reduction should be performed by dividing the 
number of kerbs by two. In the other cases, th e rate of sampling should be reduced by two.  
 
 
Annex B  
(normative)  
Procedure for acceptance testing of a consignment at delivery  
 
B.1 General  
The sampling procedure and compliance criteria for a consignment at delivery distinguishes two cases:  
- Case I:  The product has not been submitted to an assessment of  conformity by a third 
party (see 6.1.1);  
 
- Case II:  The product has been submitted to an assessment of  conformity by a third party.  
 
If case II applies, acceptance testing is not necessary, except in  case of dispute (see 6.1.2).  
The test for visual aspects shall be carried out prior to the tests for the other properties. The test shall be 
performed by the purchaser and manufacturer jointly at a location agreed between them, normally the site or 
factor y. 
 
Tests, except for visual aspects, shall be carried out in a laboratory agreed by the purchaser and the 
manufacturer. They both shall be given a reasonable opportunity to witness the sampling and testing. The tests 
may be carried out with the manufacturer's reliably calibrated test equipment.  
 
In case of dispute only the contentious property or properties shall be tested.  
  
  23    
31 B.2 Sampling procedure  
B.2.1  General  
The required number of kerbs shall be sampled from each batch of the consignment of kerbs  up to the 
following quantities according to the cases defined in B.1:  
- Case I :  
-      Case II:  1 000 m;  
depending upon the circumstances of the case in dispute, up to 2 000 m.  
 
However, a partial batch of the consignment shall be added to the previous full batch when the quantity of the partial 
batch is less than half of the quantities given above.  
 
The kerbs for testing shall be selected as being representative of the consignmen t and shall be evenly distributed 
through the consignment.  
 
B.2.2 Number of kerbs to be sampled  
The number of kerbs to be sampled from each batch shall be in accordance with Table B.1.  
 
B.2.3 Sampling plan  
  24 Table B.1 — Sampling plan  
 
Property  Requirement  
_ Testing method   Case I  Case II 3) 
Visual apsects  5.4 Annex I 8" 4 (16)1) 
Thickness of facing layer  5.1 Annex C.6 2) 8 4 (16)  
Shape and dimensions  5.2 Annex C  -,=- 
co 
❑0 cf) 
I 
4 (16) "  
Bending strength  5.3.3 – Table  3 Annex E 4 (16) "  
Abrasion resistance 
(classes 3 and 4)  5.3.4  Annex F or G 3 
Slip/skid resistance (only 
where tested)  5.35 Annex H 5 1) 5 1) 
Weathering resistance  
- class 2  
- class 3  5.3.2  
5.3.2  Annex D  
Annex ❑ 3  
3 3 (9) 
3 
) These kerbs  may be used for subsequent tests.  
2) C.6 only applies for kerbs with a facing layer.  
3) The number between brackets is the number to be sampled to avoid secondary sampling from the 
batch if, on the basis of the compliance criteria (see B.3.2), additional kerbs shall be tested to assess 
compliance.  
 
B.3 Compliance criteria  
B.3.1 Visual aspects  
When required in accordance with 5.4, the texture and colour of the sample shall show no significant 
difference to any reference sample supplied by the manufacturer and approved by the purchaser.  
 
No kerb of the sample tested shall show cracking or flaking. Kerbs with a facing layer shall not show 
delaminations.  
 
B.3.2 Other properties  
In case I,  the compliance criteria for type testing of Table 6 apply.  
 
In case II,  the compliance criteria for attributes of 6.3.8 apply for the properties included. For the  
other properties, the compliance criteria of Table 6 apply.   
  25    Annex C  
(normative)  
Measurement of dimensions of a single unit  
 
Alternative test methods, e. g. go and no -go gauges, may be used provided at least the same accuracy is achieved as in 
the following test method.  
 
C.1 Preparation  
Remove all (lashings and burrs from the unit to be measured.  
 
C.2 Overall dimensions  
 
C.2.1 Apparatus  
Measuring equipment capable of measuring with an accuracy of 0.5 mm.  
 
C.2.2  Procedure  
 
C.2.2.1 Length  
Measure the overall length of a kerb at the front and back at 10 mm above the bottom in whole millimetres . 
Record the measurements and the calculated difference. The chase and draw shall not be 1 taken into account.  
 
C.2.2.2 Width  
Measure the width on both ends of a kerb at the top (only if the width at the top is intended to be equal to the width at 
the bottom) and at 10 mm from the bottom. Record the measurements in whole millimetres Iand the calculated 
difference.  
 
C.2.2.3 Height  
Measure the height at the back of the kerb at 10 mm from both ends. Record the measurements in whole 1 
millimetres and the calculated difference.  
 
C.3 Draw  
 
C.3.1 Apparatus  
Measuring equipment capable of measuring with an accuracy of 0.5 mm.  
 
C.3.2 Procedure  
Place two kerbs together (or the two halves of one kerb after the bending test) and measure the opening 
at the top between the two units. Record the mean opening in whole millimetres.  
 
When the specification is in angular terms, use appropriate tables and record the angle.  
 
C.4 Chase  
 
C.4.1 Apparatus  
 
Measuring equipment capable of measuring with an accuracy of 0.5 mm.  
 
C.4.2 Procedure  
Put the kerb on a side and measure the chase at both ends of the unit. Record the appropriate 
dimensions of the chase in whole millimetres.  
 
C.5 Flatness and Straightness  
 
C.5.1 Apparatus  
Measuring equipment capable of  measuring with an accuracy of 0.1 mm.  
 
C.5.2 Procedure  
The maximum convex and concave deviation shall be measured along the trafficked face.  
 
C.6 Thickness of facing layer  
 
C.6.1 Apparatus  
Measuring equipment capable of measuring with an accuracy of 0.5 mm.  26 C.6.2 Procedure  
Take a unit which has been broken.  
Measure the thickness of the facing layer on the broken face at the point where, by visual inspection, the 
value will be a minimum. Record the measurement to the nearest millimetre . Isolated particles of 
aggregate protruding into the facing layer shall be ignored.  
 
C.7 Test report  
The test report shall include all the measurements taken. See also clause 8.  
  
  27    Annex D  
(normative)  
 
Determination of total water absorption  
 
D.1 Principle  
After conditioning the specimen to (20 ± 5) °C it is soaked to constant mass and then oven dried to 
constant mass. The loss in mass is expressed as a percentage of the mass of the dry specimen.  
 
D.2 Specimen  
Cut two specimens, one from each end of the kerb. The specimens may be sawn or cored and shall have 
a mass greater than 2 .5 kg but not more than 5 .0 kg. If the kerb is composed of two mixes the specimens 
shall contain the mixes in similar proportions to th ose of the kerb.  
 
D.3 Materials  
Potable water.  
 
D.4 Apparatus  
 
D.4.1 Ventilated drying oven  with a capacity in litres over an area of ventilation channels in square I 
millimetres less than 0 .2 in which the temperature may be controlled to (105 ± 5) °C. It shall have a 
volume at least 21/2 times greater than the volume of specimens to be dried at any one time.  
 
D.4.2 Flat based vessel  having a capacity at least 21/2 times the volume of the samples to be 
soaked and a depth at least 50 mm greater than the height of the specimens in the attitude that they 
will be soaked.  
 
D.4.3 Balance reading in grams and accurate to 0.1 % of the reading.  
 
D.4.4 Stiff brush.  
 
D.4.5 Cloth.  
 
D.5 Preparation of the test specimens  
 
Remove all dust, flashing, etc. with a brush and ensure that each specimen is at a temperature of (20 
± 5) °C.  
 
D.6 Procedure  
Immerse the specimens in potable water at a temperature of (20 ± 5) °C using the vessel until constant  
mass M 1 is reached. Separate the specimens from each other by at least 15 mm and ensure a minimum  
of 20 mm water above them. The minimum period of immersion shall be 3 days and constant mass shall 
be deemed to have been reached when two weighings performed at an interval of 24 h show a difference 
in mass of the specimen of less than 0.1 %. Before each weighing wipe the specimen with the cloth 
which has been moistened and squeezed to remove any excess of water. The drying is correct when the 
surface of the concrete  is dull.  
 
Place each specimen inside the oven in such a way that the distance between each specimen is at least 
15 mm. Dry the specimen at a temperature of (105 ± 5) °C until it reaches constant mass M2. The 
minimum period of drying shall be 3 days and constant mass shall be deemed to have been reached 
when two weighings performed at an interval of 24 h show a difference in mass of the specimen of less 
than 0 .1 %. Allow the specimens to cool to room temperatur e before they are weighed.  
 
D.7 Calculation of test results  
 
Calculate the water absorption W a of each specimen as a percentage of its mass from the equation:  
 
where M 1 is the initial mass of the specimen (g); where M2 is the final mass of the specimen (g). 
Calculate the mean value as a test result for the unit.  
 
 28 D.8 Test report  
The test report shall give the values of water absorption for each of the specimens. 
See also clause 8.   
  29    (  )  Annex E  
(normative)  
 
Measurement of bending strength  
 
E.1 Apparatus  
 
The transverse testing machine shall have a scale with an accuracy of ± 3 % over the range of the 
anticipated test loads and shall be capable of increasing the load at specified rates.  
 
It shall be constructed in such a way that it can induce three point bending into the sample without 
torsion (see Figure F.1).  
 
The length of the supports shall be at least equal to the width of the sample as tested and the load 
shall be applied through a swivel joint on a (40 ± 1) mm diameter pad of steel with a minimum 
thickness of 20 mm.  
 
The lower bearers shall be rigid and round or rounded to a radius of (20 ± 1) mm.  
 
 
 
Key 
1 Centre of gravity line  
2 Packing piece  
3 Hardwood wedge or mortar pack 
Figure E.1 — Principle of testing  
 30 
47 E.2 Preparation  
 
Use whole units and remove any burrs and high spots, if necessary. Immerse the units in water at 
(20 ± 5) °C for (24 -± 3) h, remove, wipe dry and test immediately.  
 
Other methods of preparation may be used for routine testing providing there is a correlation between the 
results of the two methods.  
 
E.3 Procedure  
 
The distance between the bearers and the ends of the kerb shall be 100 mm, but if the span is less 
than four times the vertical dimension of the kerb as placed in the testing machine, the distance 
between the bearers and the end of the kerb shall be reduced to half the vertical dimension of the 
kerb in the test position.  
 
If, after this reduction, the span is still less than four times this vertical dimension, this test cannot be 
performed.  
 
The actual span between the bearers shall be within 0.5 % of the specified span rounded to the nearest 
millimetre and recorded.  
 
Apply the load ± 5 mm from the cent re of gravity line of the kerb.  
 
The kerb shall always be tested with the biggest dimension of the cross section horizontally.  
 
Place the specimen symmetrically on the bearers of the testing machine with its greater cross -
sectional dimension horizontal and  place a plywood packing of (4 ± 1) mm thick under the steel pad.  
 
When products having profiles are to be tested, insert a suitable hardwood wedge or mortar pack 
between the unit and the pad.  
 
Apply the load without shock and increase the stress at a rate of (0.06 ± 0.02) MPa/s until the specimen 
fails. Record the failure load P to 100 N.  
 
E.4 Calculation of test results  
Using the work dimensions of the failure plane calculate the second moment of area I about a horizontal 
axis through the centre of the area of the failure plane.  
 
Calculate the strength, T, in megapascals of the kerb tested from the equation:  
 
T= P x L x y  
4 x I 
where  
T is the strength, in megapascals;  
 
P is the failure load in newtons;  
 
L is the distance apart of the supports in millimetres;  
 
I is the second moment of area; determined from the work dimensions;  
 
y     is the distance from the centroid to the extreme tensile fibre.  
 
Record the individual result in megapascals.  
 
E.5 Test report  
The test report shall include the strength, T, of the kerb. 
See also clause 8.   
  31    Annex F  
(normative)  
 
Measurement of abrasion resistance  
 
F.1 Principle of wide wheel abrasion test  
The test is carried out by abrading the upper part of the face of a kerb with an abrasive material under standard 
conditions.  
 
F.2 Abrasive material  
The abrasive required for this test consists of a material comprising fused alumina (corundum) with a grit size of 
F80 in accordance with ISO 8486 -1:1996. It shall not be used more than three times.  
 
F.3 Apparatus  
The wearing machine (see Figure F.1) is essentially made of a wide abrasion wheel, a storage hopper with one or 
two control valves to regulate the output of the abrasive material, a flow guidance hopper, a clamping trolley and a 
counterweight.  
 
When two valves are used, one shall be used to regulate the rate of flow and can be permanently set while the 
other is used to turn the flow on and off.   32  
Key 
1 Clamping trolley  
2 Fixing screw  
3 Specimen  
4 Control valve  
5 Storage hopper  
6 Flow guidance  
7 Wide abrasion wheel  8 Counterweight  
9 Slot  
10 Groove  
11 Abrasive material flow  
12 Abrasive collec tor 
13 Wedge  
 
Figure F.1 — Principle of wearing machine  
 
  33    The wide abrasion wheel shall be made of a steel conforming to EN 10083 -2 and with a Brinnel 
hardness of between 203HB and 245HB (as defined in EN ISO 6506 -1, EN ISO 6506 -2 and EN ISO 
6506 -3). Its diameter shall be (200 ± 1) mm and its width shall be (70 * 1) mm. it shall be driven to 
rotate 75 revolutions in (60 ± 3) s.  
 
A mobile clamping trolley is mounted on bearings and forced to move forwards to the wheel by a 
counterweight.  
 
The storage hopper containing the abrasive material feeds a flow guidance hopper.  
 
The flow guidance hopper may be cylindrical and shall have a slotted outlet. The length of the slot shall 
be (45 ± 1) mm and width shall be (4 ± 1) mm. The body of the flow guid ance hopper shall be at least 
10 mm bigger than the slot in all directions. in the case of a rectangular hopper with at least one of the 
sides inclined down to the length of the slot, these dimensional limitations are not necessary 
(see Figure F.2, example  2). 
 
Dimensions in millimetres  
 
 
,  
 
 
a, b, c > 10  
Key 
A Vertical side  
B Inclined side 
See Figure  F.1 
 
Figure F.2 — Position of slot in the base of the flow guidance hopper  
 
The distance of the fall between the slot and the axle of the wide abrasion wheel  shall be (100 ± 5) 
mm and the flow of the abrasive shall be 1 mm to 5 mm behind the leading edge of the wheel  
(see Figure F.3). 
 34 3 
  
 
dimensions in millimetres  
 
 
  
Side view  Side view  
 
 
Plan view  Plan view 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Key 
See Figure F.1 
 
 
Figure F.3 — Position of slot relative to wide abrasion wheel  
 
 
 
The flow of the abrasive material from the flow guidance hopper shall be at least at a minimum rate of 
2.5 L/min onto the wide abrasion wheel. The flow of abrasive shall be constant and the minimum level of 
the abrasive in the flow guidance hopper shall be 25 mm (see Figure F.3). 
 
Useful tools for measuring the results are:  
 
a magnifying glass preferably equipped  with a light, a steel ruler and a digital calliper.  
 
  35    F.4 Calibration  
 
The apparatus shall be calibrated after grinding 400 grooves or every two months whichever is the lesser and 
every time there is a new operator, a new batch of abrasive, or a new abrasion wheel.  
 
The abrasive flow rate shall be verified by pouring the material from a height of approximately 100 mm into a pre -
weighed rigid container with a smooth rim, of height (90 ± 10) mm and of known volume when filled to the top, this 
shall be approximately 1 I. As the container fills, the pourer shall be raised to maintain approximately the 100 mm fall. 
When the container is filled, the top shall be struck off level and weighed to determine the mass of abrasive for a 
known volume i.e. t he density. Abrasive shall be run through the wearing machine for (60 ± 1) s and collected 
below the abrasion wheel in a pre -weighed container of at least 3 I capacity. The filled container shall be 
weighed and from the density determined above, the rate of abrasive flow can be verified as more than or equal 
2.5 l/min.  
 
The apparatus shall be calibrated against a reference sample of Boulonnais Marble' using the procedure in F.6 
and the counterweight adjusted so that after 75 revolutions of the wheel in (60  ± 3) s the length of the groove 
produced is (20 .0 ± 0 .5) mm. The counterweight shall be increased or decreased to increase or decrease the 
groove length respectively. The clamping trolley/counterweight assembly shall be checked for undue friction.  
The groove shall be measured using the procedure in F.7 to the nearest 0 .1 mm and the three results averaged 
to give the calibration value.  
 
An alternative material may be used for the reference sample if a good correlation is established with a reference 
sample of 'Boulonnais Marble'.  
 
The 'Boulonnais Marble' reference is:  
‘Lunel demi -clair', thickness: > 50 mm cut perpendicular to the bedding, ground with a diamond grit 
size 100/120, roughness: Ra (1 .6 ± 0.4) µm when measured with a stylus measuring instrument in 
accordance with ISO 4288.  
 
At every calibration of the apparatus the squareness of the sample supports shall be checked.  
The groove on the reference sample shall be rectangular with a difference between the measured length of the 
groove at ei ther side not exceeding 0 .5 mm. If necessary check that:  
 
the sample has been held square to the wheel;  
 
the clamping trolley and the slot from the flow guidance hopper are parallel to the wheel axle; the flow 
of abrasive is even across the slot;  
 
the friction in the trolley/counterweight assembly is not undue.  
 
F.5 Preparation of the specimen  
The test specimen shall be a whole product or a cut piece measuring at least 100 mm x 70 mm incorporating 
the upper face of the unit and be (60 ± 10) mm thick.  
 
The test piece shall be clean and dry.  
 
The upper part of the face, which shall be tested, shall be flat within a tolerance of ±1 mm measured in accordance with 
C.5 in two perpendicular directions, but over 100 mm.  
 
If the upper part of the face has a roug h texture or is outside this tolerance it shall be lightly ground to produce a 
smooth flat surface within tolerance.   36 Immediately before testing, the surface to be tested shall be cleaned with a stiff brush and covered with a 
surface dye to facilitate measuring the groove (e.g. painting with a marker pen).  
 
F.6 Procedure  
Fill the storage hopper with dry abrasive material, moisture content not exceeding 1.0 %. Move the 
clamping trolley away from the wide abrasion wheel. Position the specimen on it so that the groove 
produced shall be at least 15 mm from any edge of the specimen and fix the specimen on a wedge to let 
the abrasive flow pass under it. Place the abrasive col lector beneath the wide abrasion wheel.  
 
Bring the specimen into contact with the wide abrasion wheel, open the control valve and simultaneously 
start the motor so that the wide abrasion wheel achieves 75 revolutions in (60 ± 3) s. Visually check the 
regul arity of the flow of the abrasive material during the test. After 75 revolutions of the wheel, stop the 
abrasive flow and the wheel. Whenever possible two tests shall be performed on each specimen.  
 
F.7 Measuring the groove  
Place the specimen under a big magnifying glass nominally at least 2 times magnification and preferably 
equipped with a light to facilitate the measuring of the groove.  
 
With a pencil with a lead diameter of 0.5 mm and hardness 6H or 7H, draw the external longitudinal limits 
(11 and 12) of the groove using a ruler (see Figure F.4). 
 
Then draw a line (A B) in the middle of the groove perpendicular to the centreline of the groove. Position 
a digital calliper  square tips on the points A and B to the inside edge of the longitudinal limits (11 and 12) of 
the groove and measure and record the dimension to the nearest ± 0.1 mm.  
 
For calibration purposes, repeat the measurement (10 ± 1) mm from the ends of the groo ve (C D) to give 
three readings.  
Dimensions in millimetres  
 
 
 
 
 
Key 
See Figure F.1 
 
Figure F.4 — Example of a tested specimen showing a groove  
 
  37    • • 1  
Some surface dyes may be removed above the groove by action of the abrasive. This shall be 
ignored in producing line II which shall be drawn where the sample surface  
 is abraded.  
 
F.8 Calculation of test results  
The result is the dimension corrected by a calibration factor and then rounded to the nearest 0.5 mm. The 
calibration factor is the arithmetic difference between 20.0 and the recorded calibration value.  
 
If two grooves have been cut in a specimen the large r value shall be taken as the result.  
 
NOTE  for example, if the calibration value is 19.6 mm and the dimension is 22.5 mm, the result is 22.5 + (20.0 – 19.6) 
= 22.9 mm, rounded to 23.0 mm.  
 
F.9 Test report  
The test report shall include the lengths of the grooves.  
 
See also clause 8.   38 Annex G 
(normative)  
 
Measuring of abrasion according to the Bohme test  
 
G.1 Principle  
 
Square sheets or cubes are placed on the BÖhme  disc abrader, on the test track of which standard 
abrasive is strewn, the disc being rotated and the specimens subjected to an abrasive load of (294 ± 3) N 
for a given number of cycles (see G.5). 
 
The abrasive wear is determined as the loss in specimen vo lume.  
 
G.2 Abrasive material  
The standard abrasive used shall be fused alumina (artificial corundum)3) designed to produce an 
abrasive wear of 1 .10 mm to 1 .30 mm when testing standard granite specimens and of 4 .20 mm to 
5.10 mm when testing standard limestone specimens. Compliance with these requirements, the 
homogeneity of the material and the uniformity of bulk density and grading of the abrasive shall be 
checked.  
 
G.3 Apparatus  
 
H.3.1 Thickness measuring device. To establish the reduction in thickness, a dial gauge, the 
plunger of which shall have a spherical bearing and an annular contact face of 8 mm outside and 
5 mm inside diameter, and a measuring table, shall be used.  
 
G.3.2 Disc abrader. The BÖhme disc abrad er as shown in Figure G.1 consists essentially of a 
rotating disc with a defined test track to receive the abrasive, a specimen holder and a loading device.  
 
G.3.3 Rotating disc. The rotating disc shall have a diameter of approximately 750 mm and be flat and 
positioned horizontally. When loaded, its speed shall be (30 ± 1) revolutions per minute.  
 
The disc shall be provided with a revolution counter and a device that switches off the disc automatically 
after 22 revolutions.  
 
G.3.4 Test track The test track shall be annular, with an inside radius of 120 mm and an outside  
radius of 320 mm (i.e. be 200 mm wide), and be replaceable.  
 
The track shall be made of cast iron with a perlitic structure, a phosphorus content not exceeding 0,35 % 
and a carbon content of more than 3 %. The track shall have a Brinell hardness of 190 to 220 HB 
2,5/187,5 (as defined in ISO 6506 -1, ISO 6506 -2 and ISO 6506 -3) determined as the mean from 
measurements taken at not less than ten points along the edge of the  track.  
 
The track surface is subject to wear in service; the resulting reduction in thickness shall not exceed 
0.3 mm and any grooves not deeper than 0,2 mm. If these values are exceeded, the track shall be 
replaced or refinished. When the track has been refinished three times, its hardness shall be determined 
anew.  
 
G.3.5 Specimen holder. The specimen holder shall consist of a U -frame approximately 40 mm high,  
with a clear distance of (5 ± 1) mm from the test track. The frame shall be positioned so that the 
centreline distance between specimen and disc is 220 mm and the angle bead of the specimen holder, 
which supports the specimen, is located at a distance of (4 ± 1) mm above the disc. The mounting of the 
specimen holder shall ensure that, during testing, no vibration occurs.  
 
G3.6 Loading device. The loading device shall consist of a lever of two arms of different length, a  
loading  weight and a counterweight, the lever being pivoted with as little friction as possible and 
positioned almost horizontally during the test. The system shall be designed to ensure that the load is 
transferred vertically via the plunger to the centre  of the specimen. The self -weight of the lever is 
balanced by the counter -weight and the scale to receive the loading weight. The force acting on the 
specimen results from the loading weight multiplied by the leverage ratio, the mass of the weight being 
selected to produce a test force of (294 ±3) N (corresponding to about 0.06 N/mm2), which shall be 
verified by calculation.  
 
  
  39    1  
Dimensions in millimetres  
 
 
 
 
 
 
 
 
 
Key 
1 Counterweight  
2 Test track  
3 Loading weight  
4 Specimen holder  
5 Specimen  
6 Rotating disc 
Figure G.1 — Principle of Böhme disc abrader  
 
 
G.4 Preparation of specimens  
Use square slabs or cubes with an edge length of (71.0 ± 1.5) mm as specimens.  
 
The contact face and the opposite face of the specimen shall be parallel and flat. For determining the 
reduction in thickness as described in G.6, the opposite face shall, if appropriate, be ground parallel or 
otherwise machined so as to be parallel.  
 
Other than as provided below the specimens shall be dried to constant mass at a temperature of 
(105 ± 5) °C, pregrinding of the contact face by four cycles (see G.5) being usually required.  
 
For the exceptional case of testing specimens in the wet or water -saturated condition (see G.5), the 
specimens shall be immersed for not less than seven days and wiped with a damp artificial sponge 
prior to each weighing so that all specimens appear equally damp.  
 
Each specimen shall be taken from no less than three different samples or workpieces of the same type.  
Prior to testing, determine the density of the specimen, ρR, by measurements, to the nearest 0.1 mm, and 
by weighing, to the nearest 0.1 g.  
 
In the case of two -layer specimens, determine the density for specimens taken separately from the 
wearing layer, such specimens also being ground prior to testing where necessary.  
 
G.5 Procedure  
Prior to the abrasion test and after every four cycles (see G.4), weigh the specimen to an accuracy of 
0.1 g.  
 
 40 Pour 20 g of standard abrasive on the test track. Clamp the specimen into the holder and, with the test 
contact face facing the track, load centrally with (294 ± 3) N.  
 
Start the disc taking care that the a brasive on the track remains evenly distributed over an area defined 
by the width of the specimen.  
 
Test the specimen for 16 cycles, each consisting of 22 revolutions.  
 
After each cycle, clean both disc and contact face, and turn the specimen progressively through 90° and 
pour new abrasive on the track as described in G.2. 
 
When testing damp or water -saturated specimens, prior to each cycle, the track shall be wiped with a 
lightly damp artificial sponge and moistened before being strewn with abrasive. From the start of the 
test, water shall be caused to drip, at a rate of app roximately 13 ml of water (corresponding to 180 
drops to 200 drops) per minute onto the track from a container with an adjustable pivoting nozzle. The 
drops shall fall through a distance of approximately 100 mm on the middle of the track at a point 
30 mm i n front of the specimen. When testing in accordance with this method, care shall be taken to 
ensure that the abrasive is continuously returned to the effective area of the track (see G.3). 
 
G.6 Calculation of test results  
Calculate the abrasive wear after 16 cycles as the mean loss in specimen volume A V, from the equation:  
 
 
 
where  
ΔV is the loss in volume after 16 cycles in cubic millimetres;  
 
Δm is the loss in mass after 16 cycles in grams;  
 
ρR is the density of the specimen or, in the case of multi -layer specimens, the density of the  
wearing layer in grams per cubic millimetre.  
 
G.7 Test report  
Report the abrasive wear to the nearest whole number of 1 000 mm3 per 5 000 mm2.  
 
See also clause 8.  
Annex H  
(normative)  
Method for the determination of unpolished slip resistance value  
(USRV)  
H.1 Principle  
The measurement of USRV on the specimen is made using the pendulum friction test equipment to evaluate the 
frictional properties of the specimen.  
 
The pendulum friction test equipment incorporates a spring loaded slider made of a standard rubber attached to 
the end of the pendulum. On swinging the pendulum the frictional force between the slider and test surface is 
measured by the reduction in length  of the swing using a calibrated scale.  
 
  41    H.2 Apparatus  
 
H.2.1 Pendulum friction tester  
 
H2.1.1 The pendulum friction test equipment shall be manufactured as shown in Figure H.1. All  
bearings  and working parts shall be enclosed as far as possible, and all materials used shall be treated to 
prevent corrosion under wet conditions.  
 
 
Key 
1 C scale (126 mm sliding length)  
2 F scale (76 mm sliding length)  
3 Pointer  
4 Pendulum  
5 Rubber slider  6 Levelling screw  
7 Test specimen holder  
8 Spirit level  
9 Vertical adjustment screw  
 
Figure H.1 — Pendulum friction test equipment  
 42 H.2.1.2 The pendulum friction test equipment shall have the following features:  
 
1) A spring loaded rubber coated slider as specified in H2.1.4 to H.2.1.10. It shall be 
mounted on the end of a pendulum arm so that the sliding edge is 510 ± 1) mm from the 
axis of suspension.  
 
2) Means of setting the support column of the equipment vertical.  
 
3) A base of sufficient mass to ensure the equipment remains stable during the test.  
 
4) Means of raising and lowering the axis of suspension of the pendulum arm so that the 
slider can: 
 
swing clear of the surface of the specimen; and  
 
be set to traverse a surface over a fixed length of (126 ± 1) mm. A gauge with this 
distance marked is required as shown in Figure H.2.  
  43     
Key 
1 Gauge  
2 Slider  
3 Reference edge  
4 Sliding length measured  
5 Actual sliding length   
 
Figure H.2 — Sliding length gauge  
5) Means of holding and releasing the pendulum arm so that it falls freely from a horizontal  
position.  
 44 6) A pointer of nominal length 300 mm, balanced about the axis of suspension, 
indicating the  position  of the pendulum arm throughout its forward swing and moving over 
the circular scale. The mass of the pointer shall be not more than 85 g.  
 
7) The friction in the pointer mechanism shall be adjustable so that, with the pendulum 
arm swinging freely from a hori zontal position, the outward tip of the pointer may be brought 
to rest on the forward swing of the arm at a point (10 ± 1) mm below the horizontal. This 
is the 0 reading.  
 
8) A circular C scale, calibrated for a sliding length of 126 mm on a flat surface, mar ked 
from 0 to 150 at intervals of five units.  
 
 H.2.1.3 The mass of the pendulum arm, including the slider, shall be (1.50 ± 0.03) kg. The centre of  
gravity shall be on the axis of the arm at a distance of (410 ± 5) mm from the axis of suspension.  
 
 H.2.1.4 The wide slider shall consist of a rubber pad (76.2 ± 0 .5) mm wide; (25.4 ± 1 .0) mm long (in  
the direction of swing) and (6.4 ± 0 .,5) mm thick, the combined mass of slider and base shall be  
(32 ± 5) g.  
 
 H.2.1.5 The slider shall be held on a rigid base with a centre pivoting axis which shall be mounted  
on the end of the pendulum arm in such a way that, when the arm is at the lowest point of its swing 
with the trailing edge of the slider in contact with the test su rface, the plane of the slider is angled at 
(26 ± 3)2 to the horizontal. In this configuration the slider can turn about its axis without obstruction to 
follow unevenness of the surface of the test specimen as the pendulum swings.  
 
 H.2.1.6 The slider shall be spring -loaded against the test surface. When calibrated, the static force  
on the slider as set by the equipment calibration procedure shall be (22.2 ± 0.5) N in its median 
position. The change in the static force on the slider shall be not greater  than 0.2 N per millimetre 
deflection of the slider.  
 
 H.2.1.7 The initial resilience and hardness of the slider shall conform to Table 1.1, and shall have a  
certificate  of conformity including the name of the manufacturer and date of manufacture. A slider 
shall be discarded when the I RHD value measured in accordance with ISO 7619 fails to conform to 
the requirements of the table or not later than three years after manuf acture.  
 
Table H.1 — Properties of the slider rubber  
Temperature °C  
Property  0 10 20 30 40 
Resilience (%))1) 43 to 49  58 to 65  66 to 73  71 to 77  74 to 79  
Hardness (IRHD)2) 53 to 65  
1) Rebound test in accordance with ISO 4662.  
2) International Rubber Hardness  Degrees in accordance with ISO 48.   
4
5
 H2.1.8 The edges of the slider shall be square and clean -cut, and the rubber free from  
contamination  by, for example, abrasive or oil. The slider shall be stored in the dark at a temperature 
in the range 5 °C to 20 °C.  
 
H2.1.9  Before using a new slider it shall be conditioned to produce a minimum width of striking  
edge of 1 mm as shown in Figure H.3. 
 
This shall be achieved by setting up the tester and carrying out five swings on a dry surface with a friction 
value above 40 on the C scale followed by a further 20 swings on the same surface after wetting.  
 
 
 
 
 
 
 
Key 
1 Rubber slider  
 
2 Aluminium backing  
 
3 Striking edge  
 
4 Worn width  
Figure H.3 — Slider assembly illustrating the maximum wear of striking edge  
 46 H.2.1.10 The slider shall be discarded when the width of the striking edge as shown in Figure H.3 
exceeds 3 mm or becomes excessively scored or burred. The slider can be reversed to expose a new 
edge, which will need to be conditioned.  
 
H.2.2 A container with potable water at (20 ± 2) °C for wetting the surfaces of the test specimen and 
slider.  
 
H.3 Calibration  
The apparatus shall be recalibrated at least annually.  
 
H.4 Sampling  
Obtain a representative sample of five kerbs of the same surface family.  
 
The face to be tested is the one that is intended to be trafficked and horizontal in use.  
 
Each kerb  in the sample shall permit a test area of 136 mm x 86 mm which is representative of the whole 
kerb. This area shall be tested using the 76 mm wide slider over a nominal swept length of 126 mm, 
readings being taken on the C scale.  
 
In the case of large ker bs, representative samples shall be cut from them for testing.  
 
H.5 Procedure  
Keep the friction test equipment, and slider, in a room at a temperature of (20 ± 2) °C for at least 30 min 
before the test begins.  
 
Immediately prior to testing with the friction tester, immerse the sample in water at (20 ± 2) °C for at least 
30 min.  
 
Place the friction tester upon a firm level surface and adjust the levelling screws so that the pendulum 
support column is vertical. The n raise the axis of suspension of the pendulum so that the arm swings 
freely, and adjust the friction in the pointer mechanism so that when the pendulum arm and pointer are 
released from the right -hand horizontal position the pointer comes to rest at the z ero position on the test 
scale.  
 
Before using a new slider condition it using the method described in H.2.1.9.  
 
Discard any slider that exceeds the requirements given in H.2.1.10.  
 
Rigidly locate the test specimen with its longer dimension lying in the track of the pendulum, and centrally 
with respect to the rubber slider and to the axis of the suspension of the pendulum. Ensure that the track 
of the slider is parallel to the long ax is of the specimen across the sliding distance.  
 
Adjust the height of the pendulum arm so that in traversing the specimen the rubber slider is in contact 
with it over the whole width of the slider and over the specified swept length. Wet the surfaces of the 
specimen and the rubber slider with a copious supply of water, being careful not to disturb the slider from 
its set position. Release the pendulum and p ointer from the horizontal position, catch the pendulum arm 
on its return swing. Record the position of the pointer on the scale (the pendulum test value). Perform this 
operation five times, rewetting the specimen each time, and record the mean of the last  three readings. 
Relocate the specimen after rotating through 180° and repeat the procedure.   
  47    H.6 Calculation of test results  
When the wide slider is used over a swept length of 126 mm, calculate the pendulum value of each specimen 
as the mean of the two recorded mean values measured in opposite directions to the nearest 1 unit on the C 
scale.  
 
The USRV is the mean pendulum value obtained on the 5 specimens.  
 
H.7 Test report  
The test report shall include the following information:  
 
1) the mean pendulum test value of each specimen;  
 
2) the mean USRV of the sample.  
 
See also clause 8.   48 Annex I  
(normative)  
Verification of visual aspects  
I.1 Preparation  
Lay out the samples at floor level after examining each kerb  for delamination.  
 
I.2 Procedure  
In natural daylight conditions an observer shall stand in turn at a distance of 2 m from the samples and 
record any kerbs showing cracks or flaking.  
 
Compare the texture and the colour with the manufacturer's sample.   
  49    Annex J  
(informative)  
 
Example of the application of the method for the evaluation of 
conformity of bending strength by variables (6.3.8.3.B.)  
J.1 General  
For factory production control by the manufacturer conformity may be determined either by attributes or 
by variables (see 6.3.8.3 B).  
 
Based on the measuring of bending strength the flow -chart (see Figure K.1) herewith shows the possible 
"routes": either by attributes or by variables; but it is always started by attributes because the variables 
route needs enough results to calculate the standard deviation.  
 
I The probability of acceptance is to be equivalent to that resulting from testing  by "Attributes" (6.3.8.3 A).  
 
J.2 Basic formula  
 
The basic formula to check the conformity of a given production is for the three strength classes:  
 
 
J.3 Acceptance factors  
Depending on the number of samples the acceptance factors are:  
n = 2  q2 = 0.6  
n = 4 q4=0.9 
n = 8  q8 = 1.2  
n = 16  q18 = 1.3  
J.4 Standard deviations s 
 
Different methods may be used for the determination of the standard deviation s depending on the I accuracy 
needed.  
 
The minimum number of results to determine the standard deviation depends on the process stability: commonly 30 
results are used, but if the stability is proved, it is possible that 15 are enough. These results (30 or 15) should 
be gathered from tests of a  representative production period, e.g. 16 production days with 8 results per 4 
production days.  
 
At regular intervals the standard deviation should be checked.  
 
J.5 Application of switching rules  
When the production is under control, the number of samples  tested decreases.  
That is logical, because the probability to produce defectives decreases. The switching rules are given in 
A.5. 
 
KS: 2017  
 
                  ©KEBS 2017 — All rights 
reserved  50  
J.6 Results  
If the result of using the formula in J.2 is positive and no individual result T is below 2.8 MPa, 4.0 MPa or 4.8 
MPa respectively according to the strength class, the corresponding production complies with the 
requirements of this standard. If the results do not meet the requirements, 6.3.7 applies.