CEN/TC 155

Date: 2025-06-13

prEN 15383:2025

Secretariat: NEN

Plastics piping systems for drainage and sewerage - Glass-reinforced thermosetting plastics (GRP) based on polyester resin (UP) - Manholes and inspection chambers

Einführendes Element — Haupt-Element — Ergänzendes Element

Élément introductif — Élément central — Élément complémentaire

CCMC will prepare and attach the official title page.

Contents Page

European foreword 4

1 Scope 5

2 Normative references 5

3 Terms and definitions 6

4 General requirements 12

4.1 Classification 12

4.1.1 Categories 12

4.1.2 Nominal stiffness 12

4.2 Materials for shaft or chamber units 12

4.2.1 General 12

4.2.2 Elastomers 12

4.2.3 Metals 12

4.3 Reference conditions for testing 13

4.3.1 Temperature 13

4.3.2 Properties of water for testing 13

4.3.3 Loading conditions 13

4.3.4 Preconditioning 13

4.3.5 Measurement of dimensions 13

4.4 Joints 13

4.4.1 Types of joint 13

4.4.2 Length and diameter of joint 13

4.4.3 Flexibility of the jointing system 13

4.4.4 Sealing ring 13

4.4.5 Adhesives 14

4.5 Joint performance 14

4.5.1 Performance requirements 14

4.5.2 Interchangeability 15

4.5.3 Test pieces 15

4.5.4 Number of test pieces for type test purposes 15

4.5.5 Test temperature 15

4.5.6 Flexible joints with elastomeric sealing rings 15

4.5.7 Rigid joints of the wrapped or cemented type 16

4.5.8 Test parameters 16

5 Geometrical characteristics 16

5.1 Diameter, wall thickness and length of GRP-UP shaft and chamber components — Dimensional requirement 16

5.2 Size of openings in manholes 17

6 Mechanical characteristics 17

6.1 General 17

6.2 Longitudinal compressive strength 17

6.2.1 Initial longitudinal compressive stress at break 17

6.2.2 Requirements 17

6.3 Longitudinal compressive load 17

6.3.1 General 17

6.3.2 Ultimate longitudinal load, F_ult 18

6.3.3 Manufacturer's declared load for which a manhole or inspection chamber ring is designed, F_d,calc and the permissible force, F_{perm, p} 18

7 Leak-tightness of manholes and inspection chambers and their joints 19

7.1 General 19

7.2 Test parameters 19

7.2.1 General 19

7.2.2 Leak-tightness when subject to internal pressure following assembly 19

7.2.3 Leak-tightness when subject to an external pressure differential 19

8 Minimum required marking 19

9 Ancillary products 20

9.1 Manhole and inspection chamber tops 20

9.2 Manhole steps and ladders 20

9.2.1 Location of steps 20

9.2.2 Load bearing capacity of installed steps 21

9.3 Precast concrete components 21

10 Dangerous substances 22

11 Manufacturer's installation recommendations 22

12 Evaluation of conformity 22

Annex A (normative) Determination of the longitudinal compressive properties measured on prism shaped test pieces 23

Bibliography 28

European foreword

This document (prEN 15383:2025) has been prepared by Technical Committee CEN/TC 155 “Plastics piping systems and ducting systems”, the secretariat of which is held by NEN.

This document is currently submitted to the CEN Second Enquiry.

This document will supersede EN 15383:2012+A1:2013.

prEN 15383:2025 includes the following significant technical changes with respect to EN 15383:2012+A1:2013:

— References to EN 14364 have been replaced with references to EN ISO 23856;

— Specifying concrete in slabs have been removed.

This document applies to:

a) manholes, when made from glass-reinforced thermosetting plastics (GRP) based on polyester resin (UP);

b) inspection chambers, when made from glass-reinforced thermosetting plastics (GRP) based on polyester resin (UP) which are intended to be used with inverts which are at a depth not exceeding 2 m.

These products are intended to be used within a drain or sewer system operating without pressure or occasionally at a head of pressure up to 1 bar.

It applies to products, and their joints, intended for use in buried installations and to be installed by open-trench techniques.

The units have a circular shape with nominal sizes as specified in EN ISO 23856.

The intended use of these products is to provide access to, buried drain or sewer systems for the conveyance of waste water at temperatures up to 50 °C, without pressure or occasionally at a head of pressure up to 1 bar, outside buildings and installed in areas subjected to vehicle and/or pedestrian traffic.

It specifies definitions including symbols, requirements and characteristics of manholes, inspection chambers, joints, materials, test methods and marking.

NOTE It is the responsibility of the purchaser or specifier to make the appropriate selections, taking into account their particular requirements and any relevant national regulations and installation practices or codes.

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.

EN 124‑1, Gully tops and manhole tops for vehicular and pedestrian areas - Part 1: Definitions, classification, general principles of design, performance requirements and test methods

EN 476, General requirements for components used in drains and sewers

EN 681‑1, Elastomeric seals — Materials requirements for pipe joint seals used in water and drainage applications — Part 1: Vulcanized rubber

EN 1119, Plastics piping systems — Joints for glass-reinforced thermosetting plastics (GRP) pipes and fittings — Test methods for leaktightness and resistance to damage of non-thrust resistant flexible joints with elastomeric sealing elements

EN 1917, Concrete manholes and inspection chambers, unreinforced, steel fibre and reinforced

EN 13101, Steps for underground man entry chambers — Requirements, marking, testing and evaluation of conformity

EN ISO 23856, Plastics piping systems for pressure and non-pressure water supply, drainage or sewerage — Glass-reinforced thermosetting plastics (GRP) systems based on unsaturated polyester (UP) resin (ISO 23856)

EN 14396, Fixed ladders for manholes

CEN/TS 14632, Plastics piping systems for drainage, sewerage and water supply, pressure and non-pressure — Glass-reinforced thermosetting plastics (GRP) based on unsaturated polyester resin (UP) — Guidance for the assessment of conformity

EN ISO 604:2003, Plastics — Determination of compressive properties (ISO 604:2002)

EN ISO 3126, Plastics piping systems — Plastics components — Determination of dimensions (ISO 3126)

ISO 2602, Statistical interpretation of test results — Estimation of the mean — Confidence interval

ISO 8533, Glass-reinforced thermosetting plastics (GRP) pipes and fittings — Test methods to prove the design of cemented or wrapped joints

For the purposes of this document, the terms and definitions given in EN ISO 23856 and the following apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp/

— IEC Electropedia: available at https://www.electropedia.org/

3.1

adjusting unit

component of a manhole used above the cover slab to adjust the height of the structure and accommodate a cover and frame

Note 1 to entry: For further explanation see Figure 2.

3.2

base unit

vertical component with integral base, with or without benching, incorporating appropriate flexible joints to provide watertight connections to pipelines with or without integral connecting pipe(s) or adaptors

Note 1 to entry: For further explanation see Figure 2.

3.3

chamber unit

vertical component of uniform cross-section

Note 1 to entry: It is classified by its nominal size and its internal height. Chamber units may incorporate flexible joints providing watertight connections to a pipeline.

Note 2 to entry: For further explanation see Figure 2.

3.4

connecting pipe

short pipe having plain, socket or spigot ends which provides a connection between a pipeline and a manhole

3.5

cover slab

horizontal unit, forming the roof of a chamber or shaft, which incorporates an opening for access and above which adjusting unit(s) and/or a cover and frame are intended to fit

Note 1 to entry: Typically, a cover slab is made of reinforced precast concrete.

Note 2 to entry: For further explanation see Figure 2.

3.6

external diameter

d_e

mean external diameter of the shaft or chamber unit at any cross section except the joint

Note 1 to entry: External diameter is expressed in millimetres (mm).

3.7

inspection chamber

drainage or sewerage fitting used to connect drainage or sewerage installations and/or to change the direction of drainage or sewerage runs, which terminates at ground level with a riser shaft having an internal diameter not less than 200 mm and not more than 800 mm

Note 1 to entry: The termination at ground level permits the introduction of cleaning, inspection and test equipment and the removal of debris but does not provide access for personnel.

Note 2 to entry: For further explanation see Figure 2.

3.8

internal diameter

d_i

external diameter of a unit minus twice its wall thickness

Note 1 to entry: Internal diameter is calculated using Formula (1) and expressed in millimetres:

d_i = d_e − 2e (1)

where

3.9

manhole

chamber, with a removable cover, constructed on a drain or sewer to permit entry by personnel, having an internal diameter not less than 800 mm

Note 1 to entry: The termination at ground level permits the introduction of cleaning, inspection and test equipment and the removal of debris as well as providing access for personnel.

Note 2 to entry: Manhole components are subject to national safety regulations and/or local provisions regarding man-entry limitations. The installer should check for compliance prior to installation.

Note 3 to entry: For further explanation see Figure 2.

3.10

normal service conditions

conveyance of wastewater, at temperature up to 50 °C, without pressure

3.11

reducing slab

horizontal transition unit, forming the roof of a chamber, which incorporates an opening for access from the shaft to the chamber and above which shaft units are intended to fit

Note 1 to entry: For further explanation see Figure 2.

3.12

shaft unit

vertical component of uniform cross-section

Note 1 to entry: When incorporated in a manhole together with chamber units shaft units have a smaller nominal size than the chamber units.

Note 2 to entry: Shaft units are classified by their nominal size and internal height (see Figure 2).

3.13

flexible joint

joint which allows relative movement between the components being joined

EXAMPLE: Socket-and-spigot joint with an elastomeric sealing element (including double socket designs).

3.14

rigid joint

joint which does not allow relative movement between the components being joined

EXAMPLE: Wrapped or cemented joint.

3.15

minimum specific initial longitudinal compressive stress at break

σ_b,s,min

manufacturer’s declared minimum value for the specific initial longitudinal compressive stress at break of the unit

Note 1 to entry: Minimum specific initial longitudinal compressive stress at break is expressed in megapascals (MPa).

3.16

initial longitudinal compressive stress at break

σ_b,s

compressive stress at break of the test piece during a short-term compression test determined using prism test pieces

Note 1 to entry: Initial longitudinal compressive stress at break (determined using prism test pieces) is expressed in megapascals (MPa).

3.17

ultimate longitudinal load

F_ult

calculated value of the concentric longitudinal load that the manhole or inspection chamber ring withstands just before break

Note 1 to entry: Ultimate longitudinal load is expressed in kilonewtons (kN).

3.18

longitudinal compressive material safety coefficient

ν

safety factor applied to the ultimate longitudinal load to determine the theoretical design load (F_d,calc)

Note 1 to entry: Regarding design load, see also 3.20.

3.19

theoretical design load

F_{d, calc}

calculated value of the maximum concentric longitudinal compressive load that a manhole or inspection chamber ring can be expected to withstand during operation, taking into account the material safety coefficient (ν)

Note 1 to entry: Theoretical design load is expressed in kilonewtons (kN).

Note 2 to entry: Regarding material safety coefficient, see 3.18.

3.20

permissible eccentric force on the manhole or inspection chamber unit

F_perm,p

calculated value of the permissible eccentric longitudinal load that the manhole or inspection chamber ring can withstand in operation, taking into account the material safety coefficient (ν)

Note 1 to entry: Permissible eccentric force on the manhole or inspection chamber unit is expressed in kilonewtons (kN).

Note 2 to entry: Regarding material safety coefficient, see 3.18.

3.21

minimum cross-sectional area at the spigot

A_s

cross sectional area of the spigot to be used in calculation of forces and loads

Note 1 to entry: Minimum cross-sectional area at the spigot is expressed in square millimetres (mm²).

Note 2 to entry: For further explanation see Figure 1.

Note 3 to entry: Minimum cross-sectional area at the spigot is calculated using Formula (2):

A_s = π [(0,5d_e)² – (0,5d_i)²] (2)

where

Key

Figure 1 — Areas and diameters referred to in this document

Key

Figure 2 — Typical types of units used in manholes and inspection chambers

Shaft and chamber units shall be made from units complying with EN ISO 23856.

Shaft and chamber units shall be classified according to nominal size (DN) and internal height. In addition, shaft and chamber units shall include nominal stiffness (SN) in their classification.

The nominal stiffness, SN, shall be in accordance with one of those given in Table 1 (see Footnotes a and b).

Where special applications require the use of units having a higher nominal stiffness than those given in Table 1, the unit shall be marked “SN N”, where N is the number equal to the unit's nominal stiffness.

Table 1 — Nominal stiffnesses (SN)

Shaft and chamber units shall be made from units complying with EN ISO 23856 and be constructed using chopped and/or continuous glass filaments, strands or rovings, mats or fabric synthetic veils, and polyester resin with or without fillers and, if applicable, additives necessary to impart specific properties to the resin. The shaft or chamber unit may also incorporate aggregates, and, if required, a thermoplastics liner.

Each elastomeric material(s) of the sealing component (if used) shall conform to the applicable requirements of EN 681‑1.

Where exposed metal components are used in the shaft or chamber units, there shall not be evidence of corrosion of the components after the metal component has been immersed in an aqueous sodium chloride solution, 30 g/l, for seven days at (23 ± 2) °C.

The mechanical, physical and chemical properties specified in all clauses of this document shall, unless otherwise specified, be determined at (23 ± 5) °C. To establish re-rating factors for all long-term properties to be used in design for service temperatures over 35 °C and up to and including 50 °C type tests shall, unless otherwise specified, be carried out at least at the maximum service temperature (50 ± 5) °C.

The joint tests described in 4.5 shall be performed at a temperature of (23 ± 15) °C.

The water used for the tests referred to in this document shall be tap water having a pH of (7 ± 2).

Unless otherwise specified, the mechanical, physical and chemical properties specified in EN ISO 23856 and clauses of this document shall be determined using circumferential and/or longitudinal loading conditions, as applicable.

Unless otherwise specified, in case of dispute store the test piece(s) in air at the test temperature specified in 4.3.1 for at least 24 h prior to testing.

The dimensions of GRP-UP components shall be determined at the temperature specified in 4.3.1. Measurements shall be made in accordance with EN ISO 3126 or otherwise using any method of sufficient accuracy to determine conformity or otherwise to the applicable limits. Routine measurements shall be determined at the prevailing temperature. In case of dispute dimensions shall be measured at the temperature specified in 4.3.1.

A joint shall be classified as either flexible (see 3.13) or rigid (see 3.14).

If requested, the manufacturer shall declare the length and the maximum external diameter of the assembled joint used between manhole components.

Neither flexible nor rigid joints are required to have any specified amount of flexibility but both are required to be watertight in service.

If used the sealing ring shall not have any detrimental effect on the properties of the components with which it is used and shall not cause the test assembly to fail the performance requirements of 4.5.

Adhesives, if required, shall be specified by the manufacturer of the joint. Adhesives shall not have any detrimental effects on the components with which it is used and shall not cause the test assembly to fail the performance requirements of 4.5.

Flexible and rigid joints, when tested using procedures detailed in either EN 1119 or ISO 8533, as applicable and using test pieces in accordance with 4.5.3, shall be in accordance with the requirements that they remain watertight and free from signs of damage when subject to each of the characteristics of the test according to Table 2.

Joints for shaft and chamber units are not to be subject to bending tests as they are not applicable to manhole elements.

Table 2 — Summary of joint tests and performance requirements for flexible and rigid joints

Where interchangeability between products from different suppliers is required, the purchaser shall ensure that the manhole or inspection chamber ring and joint dimensions are compatible with the components to be joined and the performance of the formed joint shall conform to the relevant performance requirements of 4.5.6 or 4.5.7.

A test piece shall comprise a joint and two pieces of manhole shaft or chamber ring or inspection chamber ring such that the total laying length, L, is not less than that which is required to meet the requirements of the applicable test method, i.e. EN 1119 or ISO 8533.

The number of flexible or rigid joint assemblies to be tested for each test characteristic, detailed in Table 2, shall be one. The same assembly may be used for more than one test.

The joint tests specified in 4.5.1 shall be performed at the applicable temperature in conformity with 4.3.1.

Flexible joints with elastomeric seals shall be tested for conformity with the test performance requirements under hydrostatic pressure detailed in 4.5.8, using methods of test given in EN 1119, as appropriate, with the joint free of angular deflection, draw and misalignment and assuming that the pressure rating of the piping system in which the particular type of joint is to be used is a nominal pressure (PN) equal to 1 bar. The test pieces used shall conform to 4.5.3.

Subject the test pieces to the tests required and summarized in Table 2. As these joints are not intended to be capable of resisting end-loads from the end thrust the tests shall be performed with these loads carried by external supports.

Wrapped or cemented joints shall be tested for conformity with the test performance requirements under hydrostatic pressure detailed in 4.5.8, using test pieces conforming to 4.5.3. The methods of test are those given in ISO 8533^[1] in conjunction with specific conditions assuming that the pressure rating of the piping system in which the particular type of joint is to be used is a nominal pressure (PN) equal to 1 bar.

Subject the test pieces to the tests required and summarized in Table 2. As these joints are not intended to be capable of resisting end-loads from the end thrust the tests may be performed with these loads carried by external supports.

General

When tested in accordance with EN 1119 or ISO 8533, as applicable, using the test parameters specified in Table 2, the joint performance shall conform to the requirements given in 4.5.8.2 to 4.5.8.4, as applicable.

Leak-tightness when subject to internal pressure following assembly

When assembled in accordance with the manhole or inspection chamber ring manufacturer's recommendations and then subjected to a static pressure test in accordance with EN 1119 or ISO 8533, as applicable, with a test pressure equal to 1,5 times PN, for a time period of 15 min, the joint shall remain leak-tight and there shall be no visible damage to the joint components.

Leak-tightness when subject to an external pressure differential

When subjected to a static external pressure differential test in accordance with EN 1119 or ISO 8533, as applicable, with an external pressure differential test pressure equal to −0,8 bar, for a time period of 1 h, the joint shall have a rate of pressure change not greater than 0,08 bar per hour and there shall be no visible damage to the joint components.

Leak-tightness when subject to internal pressure

When subjected to a static pressure test in accordance with EN 1119 or ISO 8533, as applicable, using a test pressure equal to 2 times PN, for a time period of 24 h, the joint shall remain leak-tight and there shall be no visible damage to the joint components.

GRP-UP shaft and chamber components shall comply with the relevant dimensional requirements specified in EN ISO 23856 relating to diameter, wall-thickness and length.

Safety requirements generally demand an opening having a diameter of at least 600 mm.

NOTE In relation to openings for personnel access into manholes, attention is drawn to the safety regulations or provisions in force at the place of use of the units.

Shaft and chamber units shall be made from units whose mechanical characteristics comply with the requirements in EN ISO 23856. In addition, the following mechanical characteristics shall be determined:

a) For type test (TT) purposes, determine the initial longitudinal compressive stress at break, using prism test pieces, σ_b,s (see 3.16), and the method described in Annex A.

b) The manufacturer shall determine and declare the required minimum specific initial longitudinal compressive stress at break, σ_b,s,min (see 3.15).

Using test pieces conforming to Clause A.3, determine the initial longitudinal compressive stress at break, σ_b,s, using the method given in Annex A.

Declared value

The initial longitudinal compressive stress at break, σ_b,s (see 3.16), obtained from the type tests (TT) shall be higher than the declared minimum specific initial longitudinal compressive stress at break σ_b,s,min (see 6.1b)).

Quality control

Both initial longitudinal compressive stresses at break, σ_b,,spigot and σ_{b,, barrel}, of all quality control tests shall be higher than the required minimum initial longitudinal compressive stress at break, σ_b,s,min.

If a correlation can be established between the compressive stress at break and the longitudinal tensile stress at break, it is permissible to derive the compressive stress at break using results from longitudinal tensile test results.

Calculate the permissible forces, which can be applied to a manhole or inspection chamber ring during operation, using the procedures given in 6.3.2 and 6.3.3.

Calculate the manhole or inspection chamber ring's ultimate compressive longitudinal load, F_ult (see 3.17), using Formula (3):

(3)

where

NOTE The area, A_s, is that of the joint surface in compression.

a) Calculate the theoretical design load, F_d,calc (see 3.20), which is the maximum load the manhole or inspection chamber ring can withstand in operation, using Formula (4) which assumes that the load is concentric and perpendicular to the joint faces (i.e. no deflection and all joint faces perfectly square).

(4)

where

The safety factor, ν, shall not be less than 1,75, unless specific agreement justifies the use of a lower value.

b) Determine the permissible force on the manhole or inspection chamber ring in operation, F_perm,p (see 3.21), using Formula (5):

(5)

where

and for this loading condition:

where

NOTE For more information on SED, see ISO 25780:2011, Annex C.

Manholes and inspection chambers and their joints for applications covered by this document shall be leak-tight against internal and external pressure between 0 bar and 0,5 bar according to EN 476.

The leak-tightness of units shall be in accordance with EN ISO 23856 and their joints shall be in accordance with 4.5.

Units of manholes and inspection chambers which do not conform to EN ISO 23856 shall be in accordance with the watertight and free from signs of damage requirements of the leak-tightness test according to Table 3.

Table 3 — Summary of leak-tightness test of manholes and inspection chambers

When tested in accordance with EN 476, as applicable, using the test parameters specified in Table 3, the unit’s performance shall conform to the requirements given in 7.2.2 to 7.2.3, as applicable.

When assembled and subjected to a static pressure test in accordance with EN 476, with a test pressure equal to 0,5 bar, for a time period of 15 min, the unit shall remain leak-tight and there shall be no visible damage to the unit’s components.

When subjected to a static external pressure differential test, with an external pressure differential test pressure equal to −0,5 bar, for a time period of 15 min, the unit shall have a rate of pressure change not greater than 0,05 bar and there shall be no visible damage to the unit’s components.

Marking details shall be printed or formed directly on the manhole or inspection chamber ring in such a way that the marking does not initiate cracks or other types of failure.

If printing is used, the colouring of the printed information shall differ from the basic colouring of the product and such that the markings shall be readable without magnification.

The following marking shall be on the outside of each manhole or inspection chamber ring, and in the case of manhole or inspection chamber rings of DN 600 or greater shall be either on the inside or on the outside surface:

a) the number of this document (i.e. EN 15383:2025);

b) the nominal size DN and diameter series, i.e. A, or B according to EN ISO 23856;

c) the stiffness rating in accordance with 4.1.2 of this document;

d) the manufacturer's name or identification;

e) the date or code of manufacture;

f) standard quality mark, if applicable.

The frame, cover or grating shall, unless otherwise specified, conform to the appropriate design in EN 124‑1.

Manhole steps and ladders shall conform to either EN 13101 or EN 14396, as applicable.

NOTE Attention is drawn to national safety regulations at the place of installation.

If a unit contains steps, these shall have a minimum projection of 120 mm from the face of the riser shaft. Vertical spacing within a finished structure shall relate to the internal height of the units and shall be within the range 250 mm to 350 mm. Single steps shall be fixed, with a tolerance of ± 10 mm, alternatively at centres in vertical plan within the range 270 mm to 300 mm. Double steps shall be fixed vertically above each other at a vertical spacing of 250 mm to 350 mm and a horizontal spacing between centres of (300 ± 10) mm (see Figure 3).

Key

Figure 3 — Location of steps

Loading requirements

For fixed ladders, the load-bearing capacity requirements according to EN 14396 apply in a construction unit with GRP shaft tubes.

For step irons, the load-bearing capacity requirements in accordance with EN 13101 shall apply in a construction unit with GRP shaft tubes.

Test pieces

A test piece consists of a unit and its installed step(s). One test piece shall be used. The test shall be performed on manhole pipes with the lowest nominal stiffness class used by the manufacturer. The test results are then applicable to pipes of higher nominal stiffness classes.

If precast concrete components are used such as cover slabs, reducing slabs and tapers, then those components shall conform to the requirements in EN 1917 and if required have a GRP coating, or other corrosion protection of same or better quality, applied to protect them from the corrosive environment within the sewer system.

Where the components characteristics have already been determined by the component manufacturer, these characteristics need not be reassessed provided that the components' performance or method of assessment remain the same and that the characteristics of the component are suitable for the intended end use of the finished product.

Products covered by this document shall not contain or release any of the substances considered dangerous according to existing national provisions.

Where the performance of the product can be affected by the declared intended use and installation would require special considerations, the manufacturer shall supply such installation recommendations that would ensure the correct performance of the product.

The assessment of conformity of glass-reinforced thermosetting plastics (GRP) based on unsaturated polyester resin (UP) manhole and inspection chamber units with the requirements of this document shall be performed using the relevant procedures detailed in CEN/TS 14632.

1. 
   (normative)
   
   Determination of the longitudinal compressive properties measured on prism shaped test pieces
   1. Scope

This annex specifies the method for determining the initial longitudinal compressive properties of manhole or inspection chamber units measured on a sample produced from ring sections cut from glass-reinforced thermosetting plastics (GRP) manhole or inspection chamber units.

• 1. General

A test piece taken from the manhole or inspection chamber wall is compressed, at a uniform rate of strain in the direction parallel to the longitudinal axis of the manhole or inspection chamber, until failure occurs.

The procedure used shall be according to EN ISO 604 and in addition include the following practices:

The initial longitudinal compressive stress at break σ_b,s is the average value of the results of compression tests on a sample of test pieces.

NOTE The expression of compressive properties in terms of the minimum original cross section is almost a universal practice. Under some circumstances the compressive properties have been expressed per unit of prevailing cross section. These properties are called “true” compressive properties.

• 1. Test-pieces
     1. General

Clause A.3 shall be used in place of EN ISO 604:2003 Clause 6.

Key

NOTE The sample surfaces in the W direction are slightly curved as they are cut from a pipe cylinder.

Figure A.1 — Geometry of a prism test piece

• • 1. Dimensions
       1. Slenderness

Test pieces shall be of such dimensions that their slenderness ratio, S_LR, calculated using Formula (A.1) is in the range from 11 to 16.

(A.1)

where

NOTE The slenderness ratio, S_LR, is the ratio of the length of a column of uniform cross section to its least radius of gyration, R_G.

(A.2)

where

(A.3)

(A.4)

where

hence

(A.5)

• • • 1. Recommended dimensions for test-pieces

The height, L, and the width, W, of the test pieces should conform to the applicable value given in Table A.1 depending on the manhole or inspection chamber's wall thickness, e.

Table A.1 — Recommended length and width of test pieces

• • 1. Production of the sample

Form the sample of test pieces by cutting a manhole or inspection chamber ring with height, L, into pieces complying with the applicable dimensions specified in A.3.2. Dimension L is parallel to the longitudinal axis of the pipe used to form the manhole or inspection chamber.

Rings for test-pieces may be cut anywhere along the manhole or inspection chamber but preferably at the end, while ensuring that the pipe ring axis is parallel to the longitudinal axis of the manhole or inspection chamber.

When preparing the test-pieces, ensure that the cut sides are parallel to each other and are at right angles to the cut surfaces of the ring from which they are prepared.

• • 1. Number of test pieces in the sample

A sample consists of five test pieces made from the same manhole or inspection chamber ring.

• • 1. Conditioning

Unless otherwise specified, store the test pieces for at least 0,5 h at the test temperature prior to testing.

In cases of dispute, condition test pieces for 24 h at (23 ± 3) °C before testing, or subject them to a mutually agreed test conditioning schedule.

• 1. Test equipment

Test equipment shall be in accordance with EN ISO 604:2003 Clause 5.

• 1. Test procedure
     1. General

The procedure shall be in accordance with EN ISO 604, except for the requirements of A.5.2, A.5.3 and A.5.4.

• • 1. Measurements

For each test piece measure and record to an accuracy of ± 0,2 mm all the external dimensions indicated in Figure A.1.

The measuring devices used shall be in accordance with EN ISO 604:2003 Clause 5.

• • 1. Compressive loading

A compressive load, F, shall be applied to each test piece as described in EN ISO 604. The change of load, ΔF, shall be recorded as a function of the change in height, ΔL, until break occurs when F = F_b (see A.6.3).

• • 1. Testing speed

Apply the compressive load using a cross-head movement between 0,8 mm/min and 6 mm/min.

EN ISO 604 sets indicative testing speed values as 5 mm/min for strength measurement. As both compressive parameters are measured during the same test, and as experience does not indicate fundamental influence from the test speed on the result, a testing speed between the values in EN ISO 604, including tolerances, may be used for the test.

• 1. Calculation and expression of results
     1. General

The procedures used for the calculation and expression of results shall be in accordance with EN ISO 604:2003 Clause 10, except for the properties determined in accordance with A.6.2, A.6.3 and A.6.4.

• • 1. Initial mean cross-sectional area, A

Calculate the initial mean cross-sectional area (A) (see Figure 1) of the test piece using Formula (A.6).

A = W × e (A.6)

• • 1. Initial longitudinal compressive stress at break

Calculate the longitudinal compressive stress at break of each individual test piece by dividing the recorded load at break, F_b (see A.5.3), by the respective initial mean cross-sectional area A determined in accordance with A.6.2.

Calculate the initial longitudinal compressive stress at break, σ_b,s as the average value of the results of compression tests on a sample of test pieces as specified in A.3.

• • 1. Statistical parameters

Calculate the arithmetic mean of each set of five test results and, if required, the standard deviation and 95 % confidence interval of the mean value according to the procedure given in ISO 2602.

• 1. Test report

The test report shall be according to EN ISO 604:2003 Clause 12, and shall also make reference to this document (including its year of publication) and this annex (i.e. EN 15383:2025 Annex A).

Bibliography

[1] ISO 25780:2011, Plastics piping systems for pressure and non-pressure water supply, irrigation, drainage or sewerage — Glass-reinforced thermosetting plastics (GRP) systems based on unsaturated polyester (UP) resin — Pipes with flexible joints intended to be installed using jacking techniques

1. ISO 8533 has a transverse bending test with a specified bending load but when testing joints for use in manholes or inspection chambers, this can be ignored as it is not applicable. ↑