KENYA STANDARD                     KS 829-2020  
                
   
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
Specification for precast concrete channels, 
edgings and quadrants  
 
 
 
 
 
 
 
 
 
 
©KEBS 2020                        Second  Edition  2020 
 
 
 
 
 
 
 
 
 
 
 
 
 KS 829:2020           
 
ii                     © KEBS 2020 — All rights reserved  TECHNICAL COMMITEE REPRESENTATION  
 
The following organizations were represented on the Techn ical 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. Institute of Quantity Surveyors of Kenya  
8. Jomo Kenyatta U niversity 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. Nairobi Western Bypass project  
16. National Housing Corporation  
17. Orkidstudio_ Design and Build  
18. QuestLinks Engineering Ltd  
19. Questworks Limited  
20. Stroutel Africa Limited  
21. Technical University of Mombasa  
22. 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 Bu reau of Standards, 
are welcome.  
 
 
 
 
 
 
 
 
 
 
© Kenya Bureau of Standards, 20 19 
  
Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 12 of 2001  of the Laws of Kenya, copyr ight 
subsists in all Kenya Standards and except as pr ovided under Section 26 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 . 
 
 
 KENYA STANDARD                                  KS 829 : 2020 
                
 © KEBS 2020 — All rights reserved            iii  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Specification for precast concrete channels, 
edgings and quadrants  
 
 
 
 
 
 
 
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:ht tp://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  041) 229448    Fax: (+254 057) 21814         
 
 
 
 
 
 
 
 
 KS 829:2020           
 
iv                     © KEBS 2020 — All rights reserved  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 accorda nce with the procedures of the Kenya 
Bureau of Standards.  
 
There is no requirement in this standard for conditioning units, i.e. adjusting the moisture content, before 
carrying out the transverse strength test.  This is because preliminary work has not ind icated a regime that 
gives consistent results.  
 
 
This standard was adopted from the following document:  
 
BS 7263:  Part 1: 1994 Specification for precast concrete flags, kerbs channels,  edgings and quadrant.  
 
Acknowledgement is hereby made for the assista nce derived from this source.  
. 
 
               
© KEBS 2017 — All rights reserved                      1 KENYA  STANDARD                       KS 829:2020  
 
Specification for precast concrete channels, edgings and quadrants  
 
1. Scope  
 
This Kenya Standard specifies the requirements for the following precast concrete products:  
 
a)  Channels;  
b)  Edgings;  
c) Quadrants.  
 
These precast concrete products, referred to as a product or products in this standard, are intended for use 
in the construction of carriageways and footways laid in accordance with KS 1537.  
 
NOTES:   1.      Appendix D gives r ecommendations on information to be given to a manufacturer in an      
enquiry or order.  
 
2. Normative references  
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies.  For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
 
KS EAS 18 -1, Cement Part 1: Composition, specifications and conformity criteria for common 
cements  
 
KS 987 -1 Modular coordination - Vocabulary appl icable to modular coordination.  
  
KS 95 Specification for natural aggregates for use in concrete.  
 
 KS 2846 Mixing water for concrete — Specification for sampling, testing and assessing the 
suitability of water, including water recovered from processes in the concrete industry, as mixing 
water for concrete.  
 
KS 1537  Code of practice for laying of precast concrete flags, kerbs, channels, edgings and 
quadrants.  
  
KS 2770 -1 Admixtures for concrete, mortar and grout -Part 1:Common requirements.  
 
KS 2770 -2 Admix tures for concrete, mortar and grout -Requirements Part 2:Concrete admixtures.  
 
KS 2770 -3 Admixtures for concrete, mortar and grout -Requirements -Part 3:Admixtures for masonry 
mortar  
 
KS 2770 -4: Admixtures for concrete, mortar and grout -Requirements -Part 4: Admixtures for grout for 
pre-stressing tendons  
 
KS 2770 -5 Admixtures for concrete, mortar and grout. Admixtures for sprayed concrete. 
Definitions, requirements, conformity, marking and labelling  
 
EN 12878 Pigments for the colouring of building materials ba sed on cement and/or lime. 
Specifications and methods of test  
 
BS 4372  Specification for engineers' steel measuring rules  
 
BS 4484 -1 Specification for measuring instruments for constructional works. Metric graduation and 
figuring of instruments for linear  measurement  
 KS 829: 2020  
            
                             © KEBS 2019 — All rights reserved  2 BS 957  Specification for feeler gauges  
 
KS ISO 7500 -2:2006  Metallic materials -Calibration and verification of static uniaxial testing 
machines -Part 2:Tension creep testing machines -Verification of the applied force.  
 
BS 2648  Performance requi rements for electrically -heated laboratory drying ovens  
    
2. Definitions   
 
For the purposes of this standard, the following definitions and those given in KS 987 -1 shall apply:  
 
2.1  
nominal size   
the size of which identifies a component  
 
2.2  
work size  
target size of a building component specified for its manufacture  
 
2.3  
secondary processing   
manufacturing process carried out after basic manufacture, before or after hardening, o n the whole unit or 
any surface  
 
Note:   Secondary processing may be used to pr ovide flat (e.g. ground) or textured (e.g. blasted) lsurfaces.  
 
2.4  
flag  
Small slab of natural or artificial stone or precast concrete  
 
2.5  
tactile flag  
flag, provided with a profiled surface, used to give warning of hazards, or to enable locations to be 
recognized, e.g. a crossing flag.  
 
3. Binders  
 
Products shall be made using cement conforming to KS EAS 18 -1. 
 
4. Aggregates  
 
Products shall be made using aggregates conforming to KS 95.  
                 
5. Water  
The water shall conform  to KS 2846.  
 
6. Admixtures  
 
Proprietary admixtures  shall conform to KS 2770.  
 
7. Pigment  
 
Pigments supplied in powder form shall conform to EN 12878  or an equivalent Kenya Standard.  Where 
pigments are used in the preparation of suspensions or slurries the pigments shall  conform to EN 12878  or 
an equivalent Kenya Standard.  
 
 
 
9. Finish                           KS 829: 2020  
 
 
© KEBS 20 20 — All rights reserved          
     3 
   
Products described as ‘natural’ shall contain no pigment ( see Clause D1(b).  Where products are made with 
two-part mixes, the surface layer shall be not less than 25 mm thick.  The surfa ce layer shall be produced as 
an integral part of the product.  
 
All arises that will be visible after laying shall be without nibs and fins.  
 
 
Note:   Profiled surfaces may be functional, (e.g. tactile) or decorative (e.g. riven).  
 
10. Dimensions and tolera nces   
 
10.1 Dimensions  
  
10.1.2  Channels and edgings   
 
Channels and edgings shall have the sizes shown in Figures 2, and shall have a length in the range 450 mm 
to 915 mm.  The length shall be measured along the vertical contact face between the channel. The ra dius of 
the vertical contact face of a channel shall be as given in Table 2.   
                  
 
Table 2.  External and internal radii for channels  
 
Dimensions  
External only  Internal and External  
1.0 2.0 3.0 4.5 6.0 7.5 
  9.0 10.5 12.0  
 
All dimension s are in millimetres  
 
 
a)Channel square : Type CS1  
 KS 829: 2020  
            
                             © KEBS 2019 — All rights reserved  4 b)Channel square : Type CS2  
 
 
b)Channel dished  : Type CD 
Figure 2  —  Bullnosed, splayed and half square and dished   channels  
 
 
 
 
  
 
                                                                                                             KS 829: 2020  
 
 
© KEBS 20 20 — All rights reserved          
     5 
  
 
 
 
Note. Quadrants in these sizes may have the following profile  
1) Bullnosed type QBN  
2) Half battered type QHB  
3) 45° splayed type QSP  
4)  
d) Quadrants (Sizes 305 × 150 × 305 × 225 or 455 × 150 or 455 ×225)  
 
Figure 4 - Edgings, quadrants  
 
 
 
All an gles except those resulting from splayed radiused or chamfered faces meeting as shown in Figure 4 
shall be square.  
 
10.1.3  Quadrants   
 Quadrants shall have the sizes shown in Figure 4(d) . 
 
10.2 Tolerances  
 
10.2.1  Channels and Edging   
The maximum dimensional deviations of any , channel and edging, measured as described in A nnex  A, shall 
be as follows:  
 
(a) Length, width or height: ± 3 mm;  
 
(b) Straightness and winding:  
 
(i) Measured over, 550 mm to 850 mm: ± 2 mm;  
 
(ii) Measured over 250 mm to 400 mm: ± 1 mm;  
 
(iii) Squareness: 2 mm clearance . 
 
11. Transverse strength  
 
   
11.2 Channels and edgings   
When sampled and tested as described in annex  B, the failing loads shall be not less than the appropriate  
value given in Table 4  
 
Table 4. Transverse strength of channnels and edgings  
 
depth as tes ted   
(see note 1)  
mm width as tested  
mm failing load ( see note 2)  
mm 
150 
125 
125 
50 
50 
50 305 
150 
255 
255 
205 
150 22.2 
8.0 
13.3 
5.1 
4.5 
3.3 
 
 note 1 .  Units are placed in the testing machine with the depth as tested being the smallest  
                 dimension.    
 
12. Water absorption  KS 829: 2020  
            
                             © KEBS 2019 — All rights reserved  6  
 
When tested as described in A nnex  C, the water absorption  for channels  and edgings    
shall not exceed the appropriate value given in Table 5.  
 
 
      Table 5.   Maximum water absorption of channels and edgings  
 
water absorption in % by mass  
channels and quadrants 
shown in Figures 2, 3 and 4  Edgings shown in Figure 4   
3.0 3.6  
 
 
13. Sampling and independent testing  
 
Samples shall be taken before the products are laid and, wherever practicable, whilst they are being m oved, 
e.g. during loading or unloading.  A sample of three products shall be taken from a  consignment of not more 
than 1, 000 products.  Each of the three products in the sample shall be taken from one of three 
approximately equal sections of the consignmen t to be tested.  
 
Each product of a sample shall be uniquely marked and accompanied by a certificate from the person 
responsible for taking the samples, stating that sampling was carried out in accordance with this standard.  
 
The sample shall be dispatched to the test laboratory, taking precautions to avoid damage to the products in 
transit.  
 
Note :  Products used for dimensional cheeks may subsequently be used for transverse strength or water absorption tests.  
 
14. Marking  
 
The following particulars relating  to products made in accordance with this s tandard shall be clearly marked 
on the delivery note, invoice, manufacturer’s or suppliers certificate, or brochure relating to a consignment 
of products:  
 
(a) The name, trade mark or other means of identification  of the manufacturing plant;  
 
(b)  The number and date of this standard;  
 
(c) Type of admixture(s) used ( see  Clause 6); 
 
 
 
15. Types of product  
  
The types of precast concrete, channels, edgings and quadrants supplied in accordance with this standard 
shall be designated as given in Table 6.  
 
Table 6 - Types of product  
 
Type  Designations  Reference  
Channels:  
Channel square  
Channel dished   
CS 
CD  
Figure 2( a) 
Figure 2( b) 
Edgings:  
Round top edging  
Flat top edging  
Bullnosed edging   
ER 
EF 
  EBN  
Figure 4(a)  
Figure 4(b)  
Figure 4(c)                           KS 829: 2020  
 
 
© KEBS 20 20 — All rights reserved          
     7 
 Quadrants:  
Bullnosed quadrant  
45º splayed quadrant  
Half battered quadrant   
QBN  
QSP  
QHB   
Figure 4(d)  
Figure 4(d)  
Figure 4(d)  
Angles:  
Internal angle  
External angles   
IA 
XA  
Figure 4(e)  
Figure 4(f)  
 
 
 
 
Annex      A 
 
Measurement of dimen sions  
 
A1. General  
 
Remove any fins or local protrusions.  
 
Note:    It is recommended that all measurements be made using a suitable steel rule conforming to  BS 
4372 or BS 4484 or an equivalent Kenya Standard.  
  
 
A3. Channels and edgings  
 
A3.1 Length  
 
Measure the length of each product to the nearest 1 mm on the face, within 25 mm of the four extreme 
corners of the profile.  Calculate the average length to the nearest 1 mm.  
    
A3.2 Width and height   
 
 Measure the width and height of each product to the n earest 1 mm at both ends.  Measure the width at the 
top and bottom of parallel faces and the overall height at the face and back of the product.  Calculate the 
average height and width to the nearest 1 mm.  
 
 
 
A5. Determination of squareness    
 
Place the st ock of an engineer’s square in contact with the moulded faces of the product.  Bring the blade 
into contact with the side of the product.  Using a feeler gauge conforming to BS 957: Part 2, check that the 
clearance  between  the  square and  the  side  of the  product at points not less than 30 mm from the top 
and the bottom does not exceed the appropriate tolerance.  
 
  
                   
 
 
 
 
 
 
 
 KS 829: 2020  
            
                             © KEBS 2019 — All rights reserved  8 Annex B 
 
Determination of transverse strength  
 
B1. Testing machine  
 
The transverse testing machine shall conform  to a grade A or grade B machine when verified in accordance 
with KS ISO 7500  Part 1 or an equivalent Kenya Standard, and be of sufficient capacity to apply loads up to 
33 kN.  It shall be provided with two steel supporting rollers, each (38 ± 3) mm in dia meter, or two steel 
bearers, each (6 ± 1) mm in width, on the supporting surfaces ( see Figure B1).  The spacing of the rollers or 
bearers shall be as given in Table B1.  
        
Table B1- Spacing of rollers or bearers for transverse strength test  
 
DIMENSION S IN MILLIMETRES  
Product  Minimum spacing centre to centre of rollers or 
minimum clear distance between bearers  
Edgings   
250 
 
 
 
In either case, one support shall be horizontal and the other so mounted as to enable loads to be applied 
without inducing an y torsional restraint in the specimen, e.g. by pivoting about an axis parallel to the length 
of the specimens. The upper member of the loading frame shall be provided with a spherical seating to 
ensure that the load is applied axially without inducing any torsion in the specimen, and a steel platen at 
least 50 mm wide and of length not less than the width of the widest specimen to be tested.  
 
B2. Procedure  
 
Place the specimen symmetrically on the bearers of the testing machine with its greater cross -section al 
dimension horizontal and bed a 50 mm wide hardwood filled on the upper surface at midpoint of the span, 
using a thin layer of plaster.  Allow the plaster to set before the test is carried out.   
 
 
Apply the load without shock and increase it at a rate n ot exceeding 18.5 N/s for each 100 mm of width as 
tested, until the specimen fails or the capacity of the machine is reached. Record the individual failing loads 
in the report, except when a specimen does not fail under the upper limit of the testing machi ne, in which 
case record the failing load as ‘greater than … kN’.  
 
                          KS 829: 2020  
 
 
© KEBS 20 20 — All rights reserved          
     9 
  
 
Figure  B1 — arrangement of loading for transverse strength test  
 
 
KS 829: 2020  
            
                             © KEBS 2019 — All rights reserved  10  
 
Annex     C 
 
Determination of water absorption  
 
C1. Apparatus  
 
C1.1  Balance, capable of weighing the specimens up to 5 kg with an accuracy of 0.1 per cent.  
 
C1.2  Suitable Concrete Sawing Machine  
 
C1.3  Ventilated Drying Oven  
 conforming to BS 2648 or an equivalent Kenya Standard, except that the internal space may exceed 0.085 
m3 in which the temperature is controlled at (1 05 ± 5) ºC, and such that the specimens can be placed in the 
oven as described in C3.1 .  
 
C1.4  Tank, deep enough  to  immerse  specimens,  containing  clean water maintained at a temperature 
of ( 20 ± 1) ºC.  
 
C1.5  Dry Airtight Vessel , e.g. desiccator, of sufficient size to contain the specimens to be tested.  
 
C2. Preparation of specimens   
 
Saw two test specimens from each of the three sample products.  Cut each specimen from either end of the 
product.  For channels take the sample from the part of the prod uct to be exposed, which may include the 
profile face.  The size of each specimen shall be as given in Table C1.  
 
Table C 1-  Size of specimens of channels and edgings for  Water absorption test  
 
Product shown in figures 2, 3 and 4  Size of specimen  
channel square type CS2 and edgings of all 
types  100 mm long x cross -section of product  
Channel square type CS1 and channel dished 
type DC  100 mm long x full depth of product x 100 mm 
wide 
 
 
C3. Procedure  
 
C3.1  Place the six specimens in the drying oven  (see C1.3) so that each one is not less than 25 mm from 
any heating surface and from each other.  Dry the six specimens in the oven for (72 ± 2) hours.  Do not place 
further specimens in the same oven during the drying process.  Allow free access of air to all su rfaces of the 
specimens.  
 
C3.2  On removal from the oven, cool each specimen for (24 ± 0.5) hours in the dry airtight vessel ( see 
C1.5 ).  Weigh each specimen and immediately completely immerse in the tank ( see C1.4 ) with its 
longitudinal axis horizontal and  at a depth such that there is (25 ± 5) mm of water over the top of the 
specimen.  
 
C3.3  Leave  the specimens immersed in the water for (30 ± 0.5) minutes.  Remove each specimen, shake 
it to  remove the bulk of the water and dry it with a cloth as rapidly a s possible until all free water is removed 
from the surface.  Weigh each specimen.   
 
 
C4. Calculation and expression of results  
 
C4.1  Calculate the mean absorption of the two specimens from each of the three products and report the 
values for the three me ans to the nearest 0.1 per cent as the water absorptions of the products.  
                          KS 829: 2020  
 
 
© KEBS 20 20 — All rights reserved          
     11 
 C4.2  Calculate the mean absorption of the two specimens from each of the three products and report the 
values of the  three means to the nearest 0.1 per cent as the water absorption s of the products.  
 
 
 
 
Annex    D 
(informative)  
 
Information to be given to the manufacturer in an  
Enquiry or order  
 
The following particulars cover the essential details to be given to the  manufacturer  for  an  enquiry or order 
to be fully understood.  
 
D1. General  
 
 Any special requirements, e.g.:  
 
 (a) Surface finish;  
 
(b) Colour;  
 
(c) Aggregate type;  
 
(d) Binder type;  
 
(a) Admixtures.  
 
 
D3. Channels   
  
(a) Figure 2 and/or channel profile (type CS1,  CS2 or CD of Figure 2) and overall dimensions;  
 
(b) Any sawn units or special instructions.  
 
D4. Channels  
 
(See Figure D1.)  
 
 (a) Number of units or number of quadrants of a circle;  
 
(b) Profile type (channel type CS1, CS2 or CD of Figure 2);  
 
(c) External or internal radius of units ( see Figure D1);  
 
(d) Radius in metres ( see 10.1.2 ). 
 
 
 
D6. Edgings  
 
(a) Number of units;  
 
(b) Profile (edgings type ER, EF or EBN of Figure 4).  
 
D7. Quadrants  
 
 (a) Number of units;  KS 829: 2020  
            
                             © KEBS 2019 — All rights reserved  12  
(b) Profile (quadrant type QBN,QHB or QSP of Figure 4);  
 
(c) Bed dimensions (305 mm or 455 mm);  
 
(d) Height dimensions (150 mm or 255 mm).  
 
 
Figure. D1 — Channels  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                         KS 829: 2020  
 
 
© KEBS 20 20 — All rights reserved          
     13 
 Annex     E 
(informative)  
 
Methods of manufacture  
 
There are many different methods for manufacturing the type of products covered by this standard.  The 
most common me thods are as follows:  
 
(a) Semi -dry process  — A moist mix is compacted by pressure or by simultaneous vibration and 
pressure or by taping.  The resulting products are demoulded immediately;  
 
(b) Wet press process — Starting with a very wet mix, excess wate r is removed under a pressure of at 
least 5 MPa over the entire surface.  The products are demoulded immediately;  
 
(c) Wet cast process — A mix with water : cement ratio in the range 0.40 to 0.55 is placed into moulds 
and compacted.  The products are norma lly demoulded on the following day.  This wet cast process is not 
used for flags covered by this standard.  
 
This Standard defines and specifies requirements and conformity for admixtures specifically intended for use 
in sprayed concrete.  
 
The types of adm ixtures covered are:  
— set accelerating and non -alkaline set accelerating admixtures;  
— consistence control admixtures;  
— bond improving admixtures.  
 
 Provisions governing the practical application of these admixtures in the production of sprayed concre te are 
not part of this Standard.