PUBLIC REVIEW DRAFT DRAFT UGANDA STANDARD  
  DUS EAS 426-3 
First  Edition  
2016-mm-dd 
 
 Reference number  
DUS EAS 426-3: 2006 
© UNBS 201 6 
  
Concrete pipes and ancillary concrete products — Part 3: 
Specification for unreinforced and reinforced concrete 
inspection chambers  
 PUBLIC REVIEW DRAFTDUS EAS 426-3: 2006 
ii                © UNBS  2016  - All rights reserved 
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2016 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and microfilm, without prior written 
permission from UNBS. 
Requests for permission to reproduce this document should be addressed to 
The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala 
Uganda 
Tel: 256 417 333 2 50/1/2/3 
Fax: 256 414 286 123 
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  
 PUBLIC REVIEW DRAFTDUS EAS 426-3:2006 
© UNBS  2016 - All rights reserved                iii National foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade, Industry and 
Cooperatives established under Cap 327, of the Laws of Uganda, as amended.  UNBS is mandated to co-
ordinate the elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT Agreement of the World Trade Organisation (WTO). 
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of representatives of 
consumers, traders, academicians, manufacturers, government and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
This Draft Uganda Standard, DUS EAS  426-3: 20 06, Concrete pipes and ancillary concrete products — Part 
3: Specification for unreinforced and reinforced concrete inspection chambers,  is identical with  and has been 
reproduced from an East African Standard, EAS 426-3 : 2006 , Concrete pipes and ancillary concrete products 
— Part 3 : Specification for unreinforced and reinforced concrete inspection chambers,  and is being propose d 
for adoption as a Uganda Standard. 
This standard was developed by the Building and civil engineering Standards Technical Committee (UNBS/TC 
3). 
Wherever the words, “ East African Standard" appear, they should be replaced by "Uganda Standard." 
 
  PUBLIC REVIEW DRAFTEAS 426-3:2006 
ICS 91.140.80 
HS 6810.20.00 
HS 6810.91.00 
  
 
© EAC 2006 First Edition 2006 
 
  
  
 
 
 
 
EAST AFRICAN STANDARD 
 
Concrete pipes and ancillar y concrete products — 
Part 3:  
Specification for unreinforced and reinforced concrete inspection 
chambers  
  
 
 
 
  
 
 
  
 
  
 
 
 
  
 
 
EAST AFRICAN COMMUNITY  
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
ii © EAC 2006 — All rights reserved  
Table of contents 
 
1 Scope ........................................................................................................................ ..................1 
2 Normative references......................................................................................................... ..........1 
3 Terms and definitions........................................................................................................ ...........2 
4 Symbols...................................................................................................................... .................2 
5 General requirements ......................................................................................................... .........2 
5.1 Application................................................................................................................ ...........2 
5.2 Concrete (4.2) ............................................................................................................. ........2 
5.3 Finish (4.3.2) ............................................................................................................. ..........4 
5.4 Geometrical characteristics (4.3.3). .....................................................................................4 
5.5 Crushing strength of chamber and shaft units (4.3.5)..........................................................7 
5.6 Vertical strength of reducing units (4.3.6) ............................................................................7 5.7 Watertightness (4.3.8) ..................................................................................................... ....8 
6 Special requirements ......................................................................................................... ..........8 
6.1 Reinforced concrete units (5.2) ...........................................................................................8  
6.2 Vertical strength of cover slabs and reducing slabs (5.2.4) .................................................8 
7 Conformity evaluation ........................................................................................................ ..........8 
7.1 Application................................................................................................................ ...........8 
7.2 Finish ..................................................................................................................... .............8 
8 Marking...................................................................................................................... ..................8 
Annex B (normative) Standards relevant to CD/K/59/2004.................................................................10 
Annex C (normative) Surface void test ... ............................................................................................11 
Annex D (normative) Dimensional tests ...... .................................................................................... ...12 
Bibliography ................................................................................................................... ....................14 
 
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
© EAC 2006 — All rights reserved iii  
Foreword 
 
Development of the East African Standards has been necessitated by the need for harmonizing requirements governing quality of products and services in East Africa. It is envisaged that through 
harmonized standardization, trade barriers which are encountered when goods and services are 
exchanged within the Community will be removed.   
In order to achieve this objective, the Partner States in the Community through their National Bureaux 
of Standards, have established an East African Standards Committee.  
The Committee is composed of representatives of the National Standards B odies in Partner States, 
together with the representatives from the private sectors and consumer organizations. Draft East 
African Standards are circulated to stakeholders through the National Standards Bodies in the Partner 
States. The comments received are discussed and incorporated before finalization of standards, in accordance with the procedures of the Community.  
East African Standards are subject to review, to keep pace with technological advances. Users of the 
East African Standards are therefore expected to ensu re that they always have the latest versions of 
the standards they are implementing.  
 
© East African Community 2006 — All rights reserved
* 
East African Community  P O Box 1096  
Arusha 
 
Tanzania  
Tel: 255 27 2504253/8 
Fax: 255-27-2504481/2504255 
E-Mail: eac@eachq.org  
Web: www.each.org 
 
[Based on BS 5911-4:2002] 
 
 
  
 
                                                 
* © 2005 EAC — All rights of exploitation in any form and by any means reserved worldwide for EAC Partner States’ NSBs.  
 PUBLIC REVIEW DRAFTPUBLIC REVIEW DRAFTEAS 426-3:2006  
© EAC 2006 — All rights reserved  1  
Concrete pipes and ancillar y concrete products — 
Part 3:  
Specification for unreinforced and reinforced concrete inspection 
chambers 
 
 
1 Scope  
 
CD/K/59/2004 specifies requirements and describes test methods for precast concrete inspection 
chambers, designed to be used for inverts not exceeding 2 metres deep, of circular, rectangular (with 
or without chamfered or rounded corners) or ellip tical cross-section, unreinforced, steel fibre and 
reinforced, with nominal sizes or nominal lengths not exceeding DN 1250 or LN 1250, respectively. 
The intended use of CD/K/59/2004 is to permit access to, and to allow aeration of, drain or sewer 
systems for the conveyance of sewage, rainwater and surface water under gravity or occasionally at low head of pressure, mainly installed in areas subjected to vehicular and/or pedestrian traffic. 
 
This part of BS 5911 specifies complementary requirements to those in CD/K/59/2004 for unreinforced and reinforced concrete inspection chambers of circular and rectangular cross-section (with or without chamfered or rounded corners), as provided for in that European Standard. This part 
also specifies requirements for inspection chamber units less than or equal to DN 1000 or LN/WN 
1000/675 not exceeding 1 metre depth to invert. The inspection chambers are mainly intended for installation in areas outside the highway and where vehicle loading is restricted. 
 
The scope of CD/K/59/2004 includes steel fibre concrete inspection chambers, which are not manufactured in the United Kingdom although this was at one time contemplated. Therefore, they have been excluded from this part of BS 5911. 
 
The scope of BS 5911-2 originally included inspection chamber covers. However, these have been 
excluded from this part of BS 5911 because they now come under the scope of BS EN 124. 
 
BS EN 752-2, BS EN 752-3, BS EN 752-4, BS EN 1295-1 and BS EN 1610 deal with the planning, 
design, installation and testing of drains and sewers. 
 
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. 
 
BS 146 , Specification for blastfurnace cements with st rength properties outside the scope of EAS 18-
1. 
 
BS 3123 , Specification for spring calipers and spring dividers. 
 
BS 3892-1 , Pulverized-fuel ash — Part 1: Specification for pulverized-fuel ash for use with Portland 
cement. 
 
BS 4027 , Specification for sulfate-resisting Portland cement. 
 
BS 4035 , Specification for linear measuring instruments for use on building and civil engineering 
constructional works — Steel measuring tapes, steel bands and retractable steel pocket rules. 
 
BS 4449 , Specification for carbon steel bars for the reinforcement of concrete. 
 
BS 4482 , Specification for cold reduced steel wi re for the reinforcement of concrete. 
 
BS 4483 , Steel fabric for the reinforcement of concrete. 
 
BS 4484-1 , Specification for measuring instruments for constructional works — Part 1: Metric 
graduation and figuring of instruments for linear measurement. 
 
BS 6699 , Specification for ground granulated blastfurnace slag for use with Portland cement. 
 EAST AFRICAN STANDARD PUBLIC REVIEW DRAFTEAS 426-3:2006  
2 © EAC 2006 — All rights reserved EAS 18-1 , Cement — Part 1: Composition, specificat ions and conformity criteria for common 
cements. 
 
BS EN 934-2 , Admixtures for concrete, mortar and grout — Part 2: Concrete admixtures — 
Definitions, requirements, conformity, marking and labelling. 
 
BS EN 1008 , 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.  
 
CD/K/59/2004, Concrete manholes and inspection chambers, unreinforced, steel fibre and reinforced. 
 
BS EN 12620 , Aggregates for concrete.  
 
3 Terms and definitions 
 
For the purpose of this part of BS 5911, the terms and definitions given in CD/K/59/2004 and the 
following apply. 
 
3.1 
cementitious content amount of cement plus any pozzolanic or latent hydraulic addition in the concrete mix 
 
4 Symbols 
 
The meanings of symbols used in this part of BS 5911 shall be as given in Table 1, together with 
those given in CD/K/59/2004, Table 2. 
 
Table 1 — Symbols 
 
Symbol Meaning Unit Reference
sh Height of studs on straightness gauge mm D.3.2 
'h Internal barrel length minus 0.03 m m D.3.2 
 
5 General requirements 
 
NOTE The numbers in brackets after subclause headings are the corresponding subclause numbers in CD/K/59/2004. 
 
5.1 Application 
 
The requirements of this part of BS 5911 shall be in addition to those specified in CD/K/59/2004 and 
for the purposes of the latter the reference specifications shall be those listed in Annex B of this 
Standard. For inspection chambers designed to be used for inverts at depths other than those not 
exceeding 2 metres deep the requirements of CD/K/59/2004 shall also apply, except as otherwise 
required by, or stated in, this part of BS 5911. 
 
5.2 Concrete (4.2) 
 
5.2.1 Composition 
 
5.2.1.1 Types of cement 
 The cement (see CD/K/59/2004, 4.1) shall either: 
 
a) be factory-produced by the cement manufacturer and conform to one of the following Standards as 
appropriate: 
 
Type of cement Standard 
CEM I  BS EN 197-1 
CEM II/B-V  BS EN 197-1 
BIII/B  BS 146 
sulfate-resisting Portland  BS 4027; or 
 
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
© EAC 2006 — All rights reserved  3 b) consist of a combination of cement conforming  to CEM I as specified in EAS 18-1 and an addition 
in the form of ground granulated blastfurnace slag (ggbs) or pulverized-fuel ash (pfa) in the 
proportions specified in 5.2.1.2 ", to be included as part of the concrete mix by simultaneously 
combining them with the other concrete materials at the concrete mixer. 
 
In all cases where combinations of cement conforming to CEM I as specified in EAS 18-1 and ggbs or 
pfa are used, the relevant proportion of ggbs or pfa shall be fully documented in the production 
records. 
 
5.2.1.2 Cementitious content  
The fully compacted concrete shall have a minimum cementitious content of not less than the relevant 
amount shown in table 2. The composition/specification of cement groups shall be as shown in Table 
3. 
 
Table 2 — Cementitious content a 
 
Class b  Aggregate 
carbonate rangec Cement or combination group Minimum cement or combination content kg/m
3 Maximum w/c ratio 
DC-2  A, B, C  1, 2, 3  340  0.45 
A  2a  400  0.40 
A  2b, 3  380  0.45 DC-3  
B, C  2, 3  340  0.45 
DC-3*  B  2, 3  380  0.45 
DC-3* *  C  2, 3  380  0.45 
A  2a  400  0.35 
A  2b, 3  400  0.40 
A  2, 3  380  0.33 
B, C  2, 3  380  0.45 DC-4  
B, C  2, 3  360  0.40 
B  2, 3  380  0.33 DC-4*  
B  2, 3  400  0.40 
C  2, 3  380  0.33 DC-4* *  
C  2, 3  400  0.40 
A  2b, 3  380  0.33 
A  2b, 3  400  0.40 
B  3  400  0.40 
B, C  3  360  0.40 DC-4m  
B, C  3  380  0.45 
DC-4m*  B  3  380  0.33 
C  3 380 0.33 DC-4m* *  
C  3  400  0.40 
a The table is consistent with the provisions of BS 8500-1:2002 and BRE Special Digest 1 [1] insofar as they relate to 
precast concrete pipeline systems, except that the maximum water/cement (w/c) ratio is limited to 0.45 in accordance with 
CD/K/60/2004, 4.2.3.2 . 
b The class designations are those for design chemical class (DC-class) in cd/k/58-1/2004, Table A.15. Where there is 
more than one option in a class the choice is at the manufacturer’s discretion. 
c See BRE Special Digest 1 - Part 4, Table 4. 
 
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
4 © EAC 2006 — All rights reserved  
Table 3 — Cement or combination groups a 
 
Type (see 5.2.1.1) Designation Standard  Grouping with 
respect to 
sulfate 
resistance 
Portland cement CEM I BS EN 197-1  1 
Portland fly ash cements CEM II/B-Vb BS EN 197-1 2ac 
Sulfate-resisting Portland cement SRPC BS 4027  3 
Blastfurnace slag cementse BIII/Bd BS 146  2be 
Combinations conforming to BS 8500-2:2002, Annex A manufactured in the concrete mixer from Portland cement and pfa or ggbs:     
CEM I cement conforming to BS EN 197-1 with a mass fraction of 6 % to 20 % of combination of pfa conforming to BS 3892-1 CIIA-V  BS 8500-2  1 
CEM I cement conforming to BS EN 197-1 with a mass fraction of 21 % to 35 % of combination of pfa conforming 
to BS 3892-1 CIIB-Vb BS 8500-2  2ac 
CEM I cement conforming to BS EN 197-1 with a mass fraction of 36 % to 55 % of combination of pfa conforming 
to BS 3892-1 CIVB-Vb BS 8500-2  2af 
CEM I cement conforming to BS EN 197-1 with a mass fraction of 6 % to 35 % of combination of ggbs conforming to BS 6699 CII-S
g BS 8500-2  1 
CEM I cement conforming to BS EN 197-1 with a mass 
fraction of 36 % to 65 % of combination of ggbs conforming 
to BS 6699 CIIIA BS 8500-2  1 
CEM I cement conforming to BS EN 197-1 with a mass fraction of 66 % to 80 %e of combination of ggbs 
conforming to BS 6699 CIIIBd BS 8500-2 2be 
a The table is consistent with BS 8500-1:2002, Table A.17 and BS 8500-2:2002, Table 1. 
b Where the proportions for sulfate resistance are required, i.e. not less than 25 % and not more than 40 % pfa, add to the 
 abbreviation “+SR”. 
c Provided the pfa content is a mass fraction of not less than 25 % of cement or combination. Where it is less than 25 %, 
 the cement of combination falls within group 1. 
d Where the proportions for sulfate resistance are required (see e), add to the abbreviation “+SR”. 
e Where the alumina content of the slag exceeds 14 %, the tricalcium aluminate content of the Portland cement fraction 
 should not exceed 10 %. Where this is not the case, the grouping with respect to sulfate resistance is “1”. 
f Provided the pfa content is a mass fraction of not more than 40 % of cement or combination. Where it exceeds 40 %, no 
 guidance is provided. 
g Where necessary, this class can be subdivided into CIIA-S (6 % to 20 % ggbs) and CIIB-S (20 % to 35 % ggbs). 
 
5.3 Finish (4.3.2) 
 
5.3.1 Surface voids 
 
With the exception of the external edges of slabs, when tested in accordance with Annex C surfaces of units shall be free from voids that permit diametrically opposite points of the rim of the gauge to 
touch the surface of the unit simultaneously. 
 Units exhibiting any surface void greater than 12 mm deep shall be deemed not to conform to this part 
of BS 5911. 
 
NOTE Voids up to and including 12 mm deep may be made good by the manufacturer — see CD/K/59/2004, 4.3.2 . 
 
5.4 Geometrical characteristics (4.3.3) 
 
5.4.1 General 
 
Subject to the requirements of this clause, the di mensions and thickness of units shall conform to 
those stated in the factory documents. 
 
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
© EAC 2006 — All rights reserved  5 5.4.2 Internal dimensions 
 
The manufacturer shall make available the sizes of inspection chamber that can be supplied. The 
internal diameter, length and width shall conform to the requirements of Table 4. 
 
5.4.3 Shape, size and position of openings in slabs 
 
Cover slabs shall conform to the requirements of Table 4 and be either:  
a) Type 1 — suitable for depths not greater than 1.2 metres to invert with a minimum size access of 
430 mm × 430 mm or 430 mm in diameter; or 
 
b) Type 2 — suitable for depths greater than 1.2 metres to invert with a maximum size access of 300 
mm × 300 mm or 350 mm in diameter. 
 Openings in cover slabs shall be circular or rectangular.  
NOTE 1 It is permissible for the vertical face(s) of an opening to be cast with a nominal release angle away from the opening, 
and to be designed to provide a seating for the inspection chamber cover. 
 
NOTE 2 A larger clear opening is permitted in Type 2 cover slabs provided the access is restricted to the above dimensions stated in b) above. 
 
NOTE 3 These provisions are consistent with the recommendations in BS EN 752-3:1997, Table NB.2. 
 
Table 4 — Inspection chambers (see Figure 1) 
 
Inspection chamber type Dimensions 
(mm) 
 A B C D E F G H 
Type 1 (for chambers not 
greater than 1.2 
m in depth from cover level to 
invert) Not less 
than 600 Not less than 75 Not less than 150 Not more than 
dimension A Not less 
than 450 Not less than 430 Not less than 430 Not less 
than 
430 
Type 2 (for chambers 
greater than 1.2 
m in depth from cover level to 
invert) Not less 
than 600 Not less than 75 Not less than 150 Not more than 
dimension A Not less 
than 450 Not more than 350 Not more than 300 Not more 
than 
300 
NOTE 1 Dimensions A to H are shown in Figure 1. 
 NOTE 2 A larger clear opening is permitted in Type 2 cover slabs provided the access is restricted to the dimensions F, G 
and H. 
 NOTE 3 The above guidance is consistent with the recommendations in BS EN 752-3:1997, Table NB.2.
 
 
 
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
6 © EAC 2006 — All rights reserved 
 
Figure 1 — Typical inspection chamber arrangements 
 
5.4.4 Benching 
 
If a base unit is supplied with benching, the slope of the benching shall be a minimum of 5 % and 
shall conform to that stated in the factory documents. 
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
© EAC 2006 — All rights reserved  7 The height of the benching from the invert of the ch annel shall be half of the nominal size of the 
largest connecting pipe, expressed in millimetres. 
 
NOTE The requirement for benching height is consistent with the recommendation of BS EN 752-3:1997, NB.4.5 . 
 
5.4.5 Dimensional tolerances 
 
5.4.5.1 Tolerances on the internal diameter of circular vertical units and related tapers 
 
The tolerances on the internal manufactured diameter of circular vertical units and related tapers shall 
be ±(3 + 0.005DN) mm (rounded to the nearest mm), limited to ±15 mm. No individual measurement, 
measured in accordance with D.1 , shall be outside the specified limits when compared to the relevant 
value stated in the factory documents (see 5.4.1 ). 
 
5.4.5.2 Tolerances on the internal size of rectangular vertical units 
 
The tolerances on the internal manufactured size of rectangular vertical units shall be ±(3 + 0.005WN) 
mm (rounded to the nearest millimetre), limited to  ±15 mm. No individual measurement, measured in 
accordance with D.1, shall be outside the specified limits when compared to the relevant value stated 
in the factory documents (see 5.4.1 ). 
 5.4.5.3 Tolerance on the thickness 
Any value of thickness measured in accordance with D.2 shall be not less than the value stated in the 
factory documents. 
 
5.4.5.4 Deviation from straightness 
 
When measured in accordance with D.3, for the internal surface of a vertical unit having an effective 
height greater than 0.5 m, both ends of the gauge shall not make contact with the surface of the unit 
when using Edge X and the two studs shall be in contact simultaneously when using Edge Y. 
 
NOTE See Figure D.1. 
 
5.4.5.5 Squareness of ends 
 
Vertical units and tapers shall be capable of being jointed with their relevant axes coincident. For 
circular chamber and shaft units this requi rement shall apply in any orientation. 
 
NOTE Squareness of ends is significant only to the extent that it relates to the type of sealing material and the performance 
of the joint assembly. 
 
5.5 Crushing strength of chamber and shaft units (4.3.5) 
 
NOTE Strength class is defined in CD/K/59/2004, 3.1.21 as the minimum crushing load in kilonewtons per metre, divided by 
one thousandth of either a unit’s nominal size (DN) or nominal length (LN). 
 
The strength classes of chamber and shaft units shall be in accordance with Table 5. Minimum 
crushing loads corresponding to strength classes shall be rounded up to the nearest 
kilonewton/metre. 
 
Table 5 — Strength classes for chamber and shaft units 
 
Nominal size/Nominal length  
DN / LN Strength class 
mm  
DN/LN < 600  40 
600 < DN/LN ≤  800  30 
800 < DN/LN ≤  1000  20 
DN/LN ≤ 1000  15 
 
5.6 Vertical strength of reducing units (4.3.6) 
 
Where an edge of an access opening is designed to be greater than 150 mm from the inner wall of 
the supporting unit, the vertical loading requirements of CD/K/59/2004 shall apply, except as 
otherwise required by, or stated in, this part of BS 5911. 
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
8 © EAC 2006 — All rights reserved The minimum vertical crushing loads for “Medium Load” and “Light Load” reducing units shall be 62.5 
kN and 12.5 kN respectively. 
 
NOTE “Light load” units are intended for installation in areas where the vertical loading is from pedestrians or the occasional  
wheel load not exceeding 1 tonne (10 kN). For “Medium Load” units, the load is increased to 5 tonnes (50 kN). 
 
5.7 Watertightness (4.3.8) 
 
For units designed to be used for inverts not exceeding 1.2 metre deep and having nominal sizes less 
than or equal to DN 1000 or LN/WN 1000/675, the internal hydrostatic pressure for the purposes of 
CD/K/59/2004, Annex C shall be 15 kPa (0.15 bar or approximately 1.5 metre water column). 
 
6 Special requirements 
 
NOTE The numbers in brackets after subclause headings are the corresponding subclause numbers in CD/K/59/2004. 
 
6.1 Reinforced concrete units (5.2) 
 
6.1.1 Concrete cover (5.2.2) 
 
The minimum concrete cover shall be 20 mm for slabs and 15 mm for all other units, or the relevant 
nominal maximum size of aggregate stated in the factory documents, whichever is the larger in each case. 
 
NOTE 1 Given the inspection procedures specified in this part of BS 5911 and the maximum permitted stabilized surface 
crack width specified in CD/K/59/2004, 5.2.3 and CD/K/59/2004, 5.2.4 , the value of minimum concrete cover is consistent with 
the serviceability conditions specified in CD/K/59/2004, 4.3.9 . Taken together, these factors are also consistent with the crack 
control provisions given in BS 8110-1 and BS 8110-2. 
 
NOTE 2 Units conveying sea water, industrial waste, etc. and those to be installed in more aggressive serviceability conditions than those specified in CD/K/59/2004, 4.3.9 may need additional concrete cover. The advice of the manufacturer 
should be sought in such a situation. 
 
6.2 Vertical strength of cover slabs and reducing slabs (5.2.4) 
 
The vertical proof load for “Medium Load” and “Light load” cover slabs and reducing slabs shall be 25 
kN and 5 kN respectively. 
 
7 Conformity evaluation 
 
7.1 Application 
 
The conformity evaluation requirements of CD/K/59/2004 shall apply to this part of BS 5911, supplemented by the following sampling procedures. 
 
7.2 Finish 
 
If subjected to the test in Annex C the finish of any unit (except for the external edges of slabs) shall conform to 5.2.1 for surface voids. 
 
7.2.1 Geometrical characteristics 
 
Sampling procedures to evaluate the conformity of internal diameter, internal size, thickness and straightness to 5.4.5.1 , 5.4.5.2 , 5.4.5.3 and 5.4.5.4 respectively shall be in accordance with those for 
“Geometrical characteristics — Units” in CD/K/59/2004, Table G.1. 
 
8 Marking 
 
In addition to the requirements of CD/K/59/2004, Clause 8 each unit or package of units shall be 
marked BS 5911-4  immediately following CD/K/59/2004  and with the letter “ R” if it is a reinforced 
concrete unit. PUBLIC REVIEW DRAFTEAS 426-3:2006  
© EAC 2006 — All rights reserved  9  
Annex A (informative) Information to be supplied in an enquiry or order  
The following particulars cover essential details required by the manufacturer so that an enquiry or 
order may be fully understood: 
 
 Reference in: 
 CD/K/60/2004  CD/K/61-1/2004 
a) quantity, cross-sectional shape(s) and nominal size(s) of 
units ― 5.4.3 
b) design chemical class (DC-class) of concrete in units 4.3.9 5.2.1 
c) if additional concrete cover is required 4.3.9 and 5.2.2 6.1.1 
d) if the products are to be fully covered by a third party 
certification scheme 7.1 Foreword 
 
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
10 © EAC 2006 — All rights reserved Annex B (normative) Standards relevant to CD/K/59/2004 
 
The reference specifications prescribed in 5.1 are listed in Table B.1. 
 
Table B.1 — British Standards relevant to CD/K/60/2004 
 
EAS 18-1 
BS 146 4.1  Cements  
BS 4027 
4.1  Aggregates  BS EN 12620 
4.1  Mixing water  BS EN 1008a 
4.1  Admixtures  BS EN 934-2 
BS 3892-1 4.1  Additions  
BS 6699 
BS 4449 
BS 4482 4.1  Reinforcing steel  
BS 4483 
a BS EN 1008:2002, 3.1 specifies that potable water does not need testing. 
   PUBLIC REVIEW DRAFTEAS 426-3:2006  
© EAC 2006 — All rights reserved  11  
Annex C (normative) Surface void test 
 
C.1 Principle 
 The purpose of this test is to evaluate whether any vo id in the surface of a unit (except for the external 
edges of slabs) conforms to the limiting requirements in 5.3.1 . 
 C.2 Apparatus 
 C.2.1 Gauge, as shown in Figure C.1. 
 
 
 
Figure C.1 — Gauge for assessing surface voids 
 
 
Subclause number Material/Characteristic 
 
C.3 Procedure 
 
Apply the ball of the gauge to the void.  C.4 Expression of result 
 Record whether diametrically opposite points in the rim of the gauge simultaneously touched the 
surface of the unit. 
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
12 © EAC 2006 — All rights reserved  
Annex D (normative) Dimensional tests 
 
NOTE At the manufacturer’s discretion it is permissible to use purpose-made “go/no-go” gauges for dimensional measurements in lieu of the apparat us specified for the tests in this Annex. 
 D.1 Internal dimensions test  
D.1.1 Principle  
The purpose of this test is to evaluate whether the internal diameter of circular vertical units and 
tapers, or the internal width/length of rectangular vertical units, conforms to 5.4.5.1 or 5.4.5.2 as 
appropriate.  
D.1.2 Apparatus 
 
D.1.2.1 Steel measuring tape or retractable pocket rule, conforming to BS 4035, with metric 
graduation and figuring conforming to BS 4484-1.  D.1.3 Procedure 
 
For circular vertical units and tapers, make three measurements of the internal diameter at each end 
at approximately 60° to each other. For rectangula r vertical units, make two measurements of each 
internal dimension at each end. For base units, take the measurements only at the upper end. For all 
units, take measurements at approximately 50 mm from the end(s) of the unit.  D.1.4 Expression of results 
 
Record whether each measured value of the internal diameter or length/width conforms to 5.4.5.1 or 
5.4.5.2 as appropriate. 
 D.2 Thickness tests 
 
D.2.1 Principle 
 
The purpose of these tests is to evaluate whether the thickness of a unit conforms to 5.4.5.3 . 
 D.2.2 Apparatus 
 
D.2.2.1 Outside spring caliper, conforming to BS 3123. 
 
D.2.2.2 Steel measuring tape or retractable pocket rule, conforming to BS 4035, with metric 
graduation and figuring conforming to BS 4484-1. 
 D.2.3 Procedure 
 
For circular vertical units, use the outside spring caliper to measure the wall thickness at 
approximately 50 mm from the end of the external barrel at the upper end, at three positions 
equidistant around the circumference of the unit.  
For rectangular vertical units, use the outside spring caliper to measure the wall thickness at 
approximately 50 mm from the end of the external barrel at the upper end, at each quarter point around the perimeter. 
 
Measure the thickness of tapers using the outside spring caliper at three positions approximately 
equidistant around the upper circumference of the unit and repeat the procedure for the lower circumference. 
 
Measure the thickness of slabs using the steel measuring tape or retractable pocket rule at each quarter point around the circumference or perimeter. PUBLIC REVIEW DRAFTEAS 426-3:2006  
© EAC 2006 — All rights reserved  13  
D.2.4 Expression of results 
 Record whether each measured value of the thickness conforms to 5.4.5.3 . 
 
D.3 Straightness test 
 D.3.1 Principle 
 
The purpose of this test is to evaluate whether the internal straightness of a vertical unit having an 
effective height greater than 0.5 m conforms to 5.4.5.4 . 
 
D.3.2 Apparatus 
 D.3.2.1 Rigid straightedge, made into a gauge of the form and dimensions shown in Figure D.1. 
 D.3.3 Procedure  
D.3.3.1 Place the straightedge within the unit with Edge X (see Figure D.1) in contact with the unit and 
on a line parallel to its vertical axis. Hold the plane of the gauge in a radial plane and make a record of whether or not both ends of the gauge, wherever so placed, were in contact with the internal surface of the unit. 
 
D.3.3.2 If both ends of the gauge were not in contact with the internal surface of the unit at both ends, 
reverse the gauge so that Edge Y, placed as above (see Figure D.1), is adjacent to the internal 
surface of the unit. 
 
D.3.4 Expression of result 
 
Record whether both ends of the gauge were in contact with the surface of the unit when using Edge X, and whether the two studs (see Figure D.1) touched the surface simultaneously when using Edge 
Y. 
 
Dimensions in mm 
 
 
 
hs = (3.5 h’ ± 5 %) in mm 
NOTE The studs should be detachable from the basic straightedge to facilitate checking and replacement.  
 
Figure D.1 — Gauge for measuring deviation from straightness 
 PUBLIC REVIEW DRAFTEAS 426-3:2006  
14 © EAC 2006 — All rights reserved  
Bibliography 
 
BS 5911-2:1982 , Precast concrete pipes, fittings and ancillary products — Part 2: Specification for 
inspection chambers. 
 BS 8110-1:1997 , Structural use of concrete — Part 1: Code of practice for design and construction. 
 
BS 8110-2:1985 , Structural use of concrete — Part 2: Code of practice for special circumstances. 
 
BS 8500-1:2002 , Concrete — Complementary British Standard to BS EN 206-1 — Part 1: Method of 
specifying and guidance for the specifier.  BS 8500-2:2002 , Concrete — Complementary British Standard to BS EN 206-1 — Part 2: 
Specification for constituent materials and concrete.  
 BS EN 124:1994, Gully tops and manhole tops for vehicular and pedestrian areas — Design 
requirements, type testing, marking, quality control. 
 
BS EN 752-2:1997 , Drain and sewer systems outside buildings — Part 2: Performance requirements. 
 
BS EN 752-3:1997 , Drain and sewer systems outside buildings — Part 3: Planning. 
 BS EN 752-4:1998 , Drain and sewer systems outside buildings — Part 4: Hydraulic design and 
environmental considerations.  BS EN 1295-1:1998 , Structural design of buried pipelines under various conditions of loading — Part 
1: General requirements.  BS EN 1610:1998 , Construction and testing of drains and sewers. 
  
 
  PUBLIC REVIEW DRAFTEAS 426-3:2006  
© EAC 2006 — All rights reserved