KENYA STANDARD  KS2770 -6:2021  
ICS ##.### 
1stEdition  
  
 © KEBS 2021   
 Admixtures  for concrete,  mortar  and grout  
Part 6: 
Sampling,  assessment  and verification  of the 
constancy  of performance . 
 
 
 
TECHNICAL COMMITTEE REPRESENTATION  
The following organizations were represented on the Technical Committee:  
1. Atkins Consulting Engineers Limited.  
2. Bamburi Cement Lafargeholcims  
3. Bens Electronics service Ltd  
4. East African Portland Cement Plc  
5. Handisi systems LTD  
6. Institution of Engineers of Kenya  
7. Institution of Quantity Surveyors of Kenya  
8. Jomo Kenyatta University of Agriculture and Technology  
9. Kenya Builders & Concrete Co Ltd  
10. Kenya Electricity Transmission Co. Ltd  
11. Malaba Keya and Partners Consultants  
12. Materials Testing and Research Division  
13. Ministry of Transport, Infrastructure, Housing, Urban Development & Public Works  
14. Ministry of water and sanitation  
15. Nairo bi Western Bypass project  
16. National Housing Corporation  
17. Orkidstudio_ Design and Build  
18. QuestLinks Engineering Ltd  
19. Questworks Limited  
20. Stroutel Africa Limited  
21. Surtech  
22. Technical University of Kenya  
23. Kenya Bureau of Standards — Secretariat 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 Direc tor, Kenya Bureau of Standards, 
are welcome.  
© Kenya Bureau of Standards, 2021 
Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 130 of 2001 of  the Laws of Kenya, copyright 
subsists in all Kenya Standards and except as p rovided under Section 25 of this Act, no Kenya Standard produced by Kenya Bureau of 
Standards 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.   KS 2770 -5:2021  
Admixtures  for concrete,  mortar  and grout  
Part 6: 
Sampling,  assessment  and verification  of the constancy  
of performance .  
Kenya Bureau of Standards,Popo Road, Off Mombasa Road,  
P.O. Box 54974 - 00200,  Nairobi, Kenya  
 +254 020 6948000, + 254 722202137, + 254 734600471  
 info@kebs.org  
 @KEBS_ke  
 kenya bureau of standards (kebs)  
  
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 acco rdance with the procedures of the Kenya 
Bureau of Standards . 
The KS 2770 consist of the following parts, under the general title Admixtures for concrete, mortar and grout  
 Part 1: Admixtures for concrete, mortar and grout — Common requirements  
 Part 2: Concrete admixtures — Definitions, requirements, conformity, marking and labelling  
 Part 3: Admixtures for masonry mortar — Definitions, requirements, conformity, marking and labelling  
 Part 4: Admixtures for grout for prestressing tendons - Definitions, req uirements, conformity, marking 
and labelling  
 Part 5: Admixtures for sprayed concrete — Definitions, requirements, conformity, marking 
and labelling  
 Part 6: Sampling, conformity control and evaluation of conformity . 
During the preparation of this standard, reference was made to the following document (s):  
EN 934 -6:2019 Admixtures  for concrete,  mortar  and grout Part 6:  Sampling,  assessment  and 
verification  of the constancy  of performance .  
 
Acknowledgement is hereby made for the assistance derived from this (these) source (s)  
This draft Standard is used with the standards of the KS 2769: 2017 series which comprises the test methods 
for admixtures.   4  
 Admixtures  for concrete,  mortar  and grout  Part 6: 
Sampling,  assessment  and verification  of the constancy  of 
performance  
1. Scope  
This document specifies the procedures for sampling and for the assessment and verification of the  constancy of  performance (AVCP)  
for admixtures  covered  by the  series  KS 2770 . 
 
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.  
KS 2770  - 1, Admixtures  for concrete,  mortar  and grout  — Part 1: Common  requirements  
KS 2770  - 2, Admixtures  for concrete,  mortar  and grout  - Part 2: Concrete  admixtures  - Definitions,  requirements,  conformity, marking  
and labelling  
KS 2770  - 3, Admixtures  for concrete,  mortar  and grout  - Part 3: Admixtures  for masonry  mortar  - Definitions,  requirements,  conformity 
and marking and labelling  
KS 2770  - 4, Admixtures for concrete, mortar and grout — Part 4: Admixtures for grout for prestressing  tendons  — Definitions,  
requirements,  conformity,  marking  and labelling  
KS 2770  - 5, Admixtures for concrete, mortar and grout — Part 5: Admixtures for sprayed concrete — Definitions,  requirements, 
conformity,  marking  and labelling  
 
3. Terms  and definitions  
For the purposes  of this document,  the following  terms  and definitions  apply.  
 
3.1.  
batch  
quantity  of admixture  which  can be considered  to have  a uniform  composition  
NOTE  A tank load can be considered  as the equivalent  of a batch.  
 
3.2.  
responsible  person  
person  appointed  by the manufacturer  whose  duties  include  implementation  of all or a defined  part of the production control manual  
 
4. Sampling  
 
4.1.  General  
Sampling  of admixtures  shall be carried  out in such  a way that the resulting  sample  is representative  of the batch to be inspected.  
The following  procedures  shall be used:  
— for type testing  and in case  of dispute,  4.2; 
— at time of delivery,  4.3; 
— for factory  production  control,  4.4.  
5  
  
 
 
If required,  sampling  shall be carried  out in the presence  of all the parties  concerned.  
 
4.2.  Sampling  from  the manufacturer's  stock  
 
4.2.1. General  
Each sample shall represent not more than one batch. For continuous production of an  admixture, one  sample taken  from up  to 25 t 
may be  regarded as representative.  
 
4.2.2. Powder  admixture  (in packages)  
 
The sample shall be composed of sub -samples from 6 packages (bags) or if the total number of packages  (bags) is less than 6, from 
all packages (bags). The sub -samples are to be taken from packages (bags)  distributed at  random throughout  the consignment.  
One of the following  procedures  shall be applied:  
a) where  the packages  contain  up to 500 g, take all the contents  of each  package;  
b) where  the packages  contain  more  than 500 g, use one of the following  methods:  
1) insert  a sampling  tube,  which  takes  a core not less than 25 mm in diameter,  into the packages  so that it takes  a core of 
the material  from substantially  the entire  length  of the package  
 
2) empty  one of the packages  to be sampled  on to a clean  dry surface  and mix the material.  Take  at least  three  portions  of 
not less than 125 g each  from different  parts  of the heap.  
 
The method  given  in 1) is the preferred  method,  but if a sampling  tube is not available,  the method  given  in 2) shall  be used.  
Repeat the procedure with each of the other packages to be sampled and thoroughly mix the sub ‑ samples obtained to form one bulk 
sample. If the bulk sample exceeds 3 kg, it shall be reduced to 3 kg,  either by coning  and quartering or by use of  a sample splitter.  
Divide  the sample  into three  equal  parts  and place  each  part in a clean,  air tight,  labelled  container.  At least  one container  
holding  1 kg shall be kept for future  reference.  Store  container(s)  in a place  that is protected from moisture, heat and light for 
one year or until the use -by date, whichever is the  shorter period.  
 
4.2.3. Liquid  admixture  
 
4.2.3.1.  General  
In order  to achieve  representative  samples  of liquid  admixtures,  one of the following  procedures  shall be applied.  
 
4.2.3.2.  Sampling  of a liquid  admixture  from  containers  
 
The sample  shall be composed  of sub-samples  taken  from 6 containers  or if the total number  of containers  is less than 6 from all 
containers.  The sub-samples  are to be taken  from containers  distributed at  random throughout  the consignment.  
Agitate the admixtures in the containers to disperse all lightly settled material. Disregard all deposits  which are  not readily  brought  into 
suspension  by such agitation  
 
Without  delay,  take sub-samples  from the selected  containers  by one of the following  procedures:  
a) where  containers  hold up to 0.5 l, take the total contents;  6  
  
 
 
b) where containers  hold more than  0.5 l take  0.5 l of the liquid  from each  container,  combine the  sub‑ samples  
obtained  in this  way and mix them thoroughly  to form one  bulk sample.  
 
4.2.3.3.  Sampling  of a liquid  admixture  from  a tank load 
 
When the load is agitated, one sample may represent the entire tank load of up to 25 000 l. The bulk  sample shall  be at  
least  3 l. 
 
Otherwise, three samples shall be taken as follows: one from the top level, one within ± 300 mm of the  mid-level of the 
fluid and one within 400 mm of the bottom of the tank. Each sample shall be not less  than 1  l. Thoroughly  mix the three  
samples  until they form one homogeneous  bulk sample.  
 
4.2.3.4.  Division  of sample  
 
The bulk sample obtained by one of the procedures described above ( 4.2.3.2 or 4.2.3.3 ) shall be divided  into 3 equal 
samples. Place in three clean bottles, label and tightly stopper. At least one bottle shall be  kept for  future  reference  for one 
year or until the  use by date, whichever  is the shorter  period.  
Store  the bottle(s)  in a place  that is protected  from heat,  frost and light.  
 
4.3. Sampling  at delivery  
 
When sampling of a consignment of an admixture is required, the sampling shall be carried out before  unloading  at the 
point  and time of delivery.  
 
4.4. Sampling  for factory  production  control  
 
Sampling procedures for factory production control shall be documented in the production control  manual.  The procedure  
shall ensure  that a representative  sample  is obtained.  
As a guide, at least one sample per batch or, in the case of continuous production, at not more than 25 t  interval s. After 
testing, a sample of not less than 250 ml should be retained for at least one year or the  shelf  life of the product,  if longer.  If 
the normal  admixture  dosage  exceeds  2 %, a larger  sample  should  be retained.  
 
4.5. Record  
All information  relevant  to the sampling  shall be recorded,  in particular:  
a) date of sampling;  
b) name  of the product;  
c) type of admixture;  
d) name  of the manufacturer;  
e) manufacturer's  batch   
f) identification  number;   
g) quantity  of batch  represented ;  
h) by the sample;  
i) physical  state;  
j) colour;  
k) names  of persons  present  and organizations  represented  during  sampling.   
7  
  
 
5. Assessment  and verification  of consistency  of performance  — AVCP  
 
5.1. General  
The compliance of admixtures for concrete, mortar and grout with the requirements of the relevant  parts of the series KS 2770  and 
with the performances declared by the manufacturer in the Declaration of performance ( DoP) shall be  demonstrated by:  
— determination  of the product  type;  
— factory  production  control  by the manufacturer,  including  product  assessment.  
The manufacturer shall always retain the overall control and shall have the necessary means to take  responsibility  for the conformity  
of the product with  its declared  performance(s).  
 
5.2. Conformity  criteria  
Composition and performance requirements and the related checks and test methods are given in the  relevant parts of the series KS 
2770 . When tested in accordance with these methods each result s hall conform  to the relevant  requirement.  
 
5.3. Type  testing  
Type testing shall be carried out to prove the conformity of the admixtures to the requirements of the  relevant  part of  the series  KS 
2770 , in the  following  circumstances:  
a) when  a new formulation  or type of admixture  is produced;  
b) when  there  is a change  in formulation  which  may have  significant  effect  on the performance  of the admixture or which 
affects the manufacturer's stated values for the product as listed under  general  requirements in  the relevant  part of the KS 
2770  series;  
c) when there is a change in the raw materials which may have a significant effect on the performance  of the admixture or which 
affects the manufacturer's stated values for the product as listed under  general  requirements in the relevant part  of the  KS 
2770  series.  
 
Type testing shall include all tests for a specific type of admixture as detailed in the relevant part of the  KS 2770 series. This shall 
include the number of samples  to be tested, all compliance characteristics, the  assessment  method and requirements.  
 
Assessment  previously  performed  in accordance  with the provisions  of this standard,  may be taken  into account provided that 
they were made to the same test method, under the AVCP system 2+ on the  same product or products of similar design, construction 
and functionality, such that the results are  applicable to the product  in question.  
 
The results of the determination of the type testing shall be documented in test r eports. All test reports  shall be retained by the 
manufacturer for at least 10 years after the last date of production of the  admixture  for concrete, mortar  and grout to  which  the test 
relates.  
 
5.4. Factory  production  control  (FPC)  
 
5.4.1. General  
The manufacturer shall document, operate and maintain production control at each factory where  admixtures  are produced.  
Production  control  shall include  control  of raw materials,  production  8  
  
 
 
processes  and the finished  product.  The production  control  procedures  shall be contained  in a production  control  manual  for 
each factory.  
 
The frequency  and requirements  for demonstrating  constancy  of performance  are given  in tables  within  the series  KS 2770 -
2 to KS 2770 -5. 
 
5.4.2. Production  control  manuals  
 
Each production control manual shall specify the procedures to ensure that admixtures supplied from  each factory conform to 
the requirements of KS 2770 -2 to KS 2770 -5. As a minimum, the following items  shall be included:  
 
a) training  for production  and quality  control  operatives  including  the level of training  necessary;  
b) procedures for the identification, sampling, approval against specification, traceability, storage and  expiry dates of raw  
materials;  
c) procedures  for servicing  and calibrating  all manufacturing  and test equipment  (see Annex  A); 
d) manufacturing  and sampling  instructions;  
e) procedures  for FPC testing  at the frequency  required  by the relevant  parts  of the KS 2770  series;  
f) details  of FPC acceptance  limits  for each  characteristic  required  by the relevant  parts  of the KS 2770  series,  
linked  to the manufacturer's  Stated  Values  for the current  Type  Testing  documentation and  Declaration of 
Performance ; 
g) action to be taken in case of non  compliance of raw materials, intermediate and finished products  including full 
traceabil ity and retesting, and procedures to investigate and eliminate the causes of  non compliance;  
h) instructions  for packaging,  labelling,  storage  and delivery  of finished  products;  
i) procedures to ensure that only admixtures which conform to the relevant part of the KS 2770 series  of standards are  
labelled as complying;  
j) records  to be prepared  and period  for which  they shall be retained  (5.4.3 ). 
 
Individual responsibilities shall be defined in the production control manual. Each responsible person  shall report to a senior 
manager who has the authority to ensure that the procedures in the production  control  manual  are fully implemented.  
Where appropriate, the production control manuals shall be supplemented by additional documented  instructions relating to 
the items listed  above.  
 
5.4.3. Production  control  records  
The following  details  shall be recorded  clearly  and in chronological  order:  
a) results  of checks  on measuring  equipment  used  in production  and testing,  including  calibration reports;  
b) raw materials  identification  and test results;  
c) production  data (type  and marking  of the admixture,  batch  identification  number,  quantity  produced,  date of production  
and any production  code);  
d) sampling  in accordance  with Clause  4; 
e) date and results of production control tests and checks, comparison with requirements and, where  appropriate, action 
taken;  KENYA STANDARD                           KS 2770 -5:2021   
 
© KEBS  2021– All rights reserved   
  
 
 
f) signature  of the responsible  person.  
These  records  shall be stored  for at least  10 years.  
 
5.4.4. Initial  inspection  of factory  and FPC 
 
Initial inspection of factory and of FPC shall be carried out when the production process has been  finalized and is in operation. The 
factory and FPC documentation shall be assessed to verify that the requirements of  this standard  are fulfilled.  
During  the inspection  it shall be verified:  
 
a) that all resources  necessary  for the achievement  of the product  characteristics  included  in this European  Standard are  in 
place  and correctly  implemented,  
b) that the FPC‑procedures  in accordance  with the FPC documentation  are followed  in practice,  
c) that the product  complies  with the product  type samples,  for which  compliance  of the product  performance to the DoP  
has been  verified.  
 
5.4.5. Continuous  surveillance  of FPC 
 
Surveillance of the FPC shall be undertaken once per year. The surveillance of the FPC shall include a  review of the FPC test 
plan(s) and production processes(s) for each type of admixture to determine if  any changes have been made since the last 
assessment or surveillance. The significance of any changes  shall be assessed.  
 
Checks  shall be made  to ensure  that the test plans  are still correctly  implemented  and that the production  equipment  is still correctly  
maintained  and calibrated  at appropriate  time intervals.  
 
The records of tests and measurement made during the production process and to finished products  shall be reviewed to ensure that 
the values obtained still correspond with those values for the samples  submitted to the determination of the  product type and that the 
correct actions have been taken for  non‑compliant products.  
 
5.4.6. Procedure  for modifications  
If modifications are made to the product, production process or FPC system that could affect any of the  product characteristics 
declared acc ording to this standard, then all the characteristics for which the  manufacturer declares performance, which may be 
affected by the modification, shall be subject to the  determination  of the product type,  as described in 5.3. 
 
Where relevant, re -assessment of the factory and the FPC system shall be performed for those aspects  which may be  affected by 
the modification.  
 
All assessments  and their results  shall be documented  in a report.