FprEN 17151-2

• Abstract:

  This document specifies a test method for determining the creep behaviour under compression of boxes made of thermoplastic materials intended for use in a modular system for non-pressure underground conveyance and storage of surface water.

• Status: Not Published
• Publication Date: 03-Feb-2027
• ICS: 23.040.01 - Pipeline components and pipelines in general
• Technical Committee: CEN/TC 155 - Plastics piping systems and ducting systems
• Drafting Committee: CEN/TC 155/WG 26 - Storm Water Management
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 07-Aug-2026
• Due Date: 11-Sep-2026
• Completion Date: 07-Aug-2026
• Ref Project: oSIST prEN 17151-2:2026 - Plastics piping systems for non-pressure underground conveyance and storage of surface water - Part 2: Test method for determination of creep behaviour of boxes

Overview

FprEN 17151-2 is a European standard developed by CEN (European Committee for Standardization) under the technical committee CEN/TC 155. It specifies the test method for determining the creep behaviour under compression of thermoplastic boxes used in modular systems for non-pressure underground conveyance and storage of surface water. These systems play a critical role in effective water management, especially in urban stormwater infrastructure, where the long-term mechanical stability of components is essential.

The standard outlines how to assess the permanent deformation (creep) of plastic boxes exposed to constant compressive stress over time, ensuring their reliability and structural integrity in underground applications.

Key Topics

• Test Scope and Applicability

  • Applicable to thermoplastic boxes used in modular piping and storage systems for surface water management.
  • Focuses on non-pressure, underground installations, typical for stormwater collection and retention systems.

• Test Methodology

  • Clear instructions for sample preparation, conditioning, and orientation according to installation.
  • Utilizes compression testing apparatus capable of maintaining constant loads and precise measurement devices for displacement, load, and temperature.
  • Specifies test environments, including temperature and humidity conditions.

• Measurement and Analysis

  • Details procedures for applying multiple test loads, recording deflection, and calculating strain as a function of time.
  • Explains calculation of the creep factor: the ratio between extrapolated strain after a given period and initial strain after load application.
  • Includes guidance on regression analysis for extrapolating long-term creep data and determining suitability of linear fits.

• Reporting Requirements

  • Lists all essential information to be provided in the test report: sample identification, test conditions, test results, plots (strain vs. log time), calculated creep factors, and any deviations or incidents that could affect results.

Applications

FprEN 17151-2 supports manufacturers, designers, and testing organizations in:

• Quality Assurance: Providing a reliable method to assess the long-term creep performance of modular plastic boxes used in stormwater management systems. This is critical for ensuring product durability.
• Product Development: Facilitating the comparison of different materials and box designs under realistic load conditions. Supports R&D by allowing the prediction of structural performance over service lifetimes.
• Compliance and Certification: Assisting in demonstrating conformity to European and national requirements for components used in non-pressure underground water conveyance and storage.
• Infrastructure Design: Enabling engineers to select and specify suitable products based on standardized test data, reducing the risk of structural failure in underground installations.
• Risk Management: Improving the predictability of surface water system performance by using rigorously tested components, which helps mitigate long-term settlement or collapse.

Related Standards

When applying or referencing FprEN 17151-2, the following standards are closely connected and should be considered:

• EN 17150: Plastics piping systems for non-pressure underground conveyance and storage of non-potable water - Test method for determination of short-term compression strength of boxes.
• FprEN 17151-1: Part 1 of this series, detailing test methods for long-term compression strength of boxes.
• EN ISO 7500-1:2018: Metallic materials - Calibration and verification of static uniaxial testing machines.
• EN ISO 899-1:2017: Plastics - Determination of creep behaviour - Part 1: Tensile creep.

Together, these standards form a comprehensive framework for testing, certification, and design of plastics piping systems for reliable, long-term surface water management.

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Keywords: FprEN 17151-2, plastics piping systems, creep behaviour, modular stormwater storage, underground conveyance, compression test method, non-pressure piping, CEN standard, surface water management, structural integrity of plastic boxes.

SLOVENSKI STANDARD
01-marec-2026
Cevni sistemi iz polimernih materialov, ki delujejo po težnostnem principu in so
položeni v zemljo, za transport in shranjevanje površinske vode - 2. del:
Preskusna metoda za ugotavljanje leznih lastnosti zabojev
Plastics piping systems for non-pressure underground conveyance and storage of
surface water - Part 2: Test method for determination of creep behaviour of boxes
Kunststoff-Rohrleitungssysteme für die drucklose unterirdische Entwässerung für Nicht-
Trinkwasser - Teil 2: Prüfverfahren zur Bestimmung des Kriechverhaltens von
Versickerungsblöcken
Systèmes de canalisations en plastique pour le transport et le stockage souterrains sans
pression des eaux de surface - Partie 2 : Méthode d’essai pour la détermination du
comportement au fluage des structures alvéolaires ultra-légères
Ta slovenski standard je istoveten z: prEN 17151-2
ICS:
23.040.03 Cevovodi za zunanje sisteme Pipeline and its parts for
transporta vode in njihovi deli external water conveyance
systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
prEN 17151-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2025
ICS 23.040.01
English Version
Plastics piping systems for non-pressure underground
conveyance and storage of surface water - Part 2: Test
method for determination of creep behaviour of boxes
Systèmes de canalisations en plastique pour le Kunststoff-Rohrleitungssysteme für die drucklose
transport et le stockage souterrains sans pression des unterirdische Entwässerung für Nicht-Trinkwasser -
eaux de surface - Partie 2 : Méthode d'essai pour la Teil 2: Prüfverfahren zur Bestimmung des
détermination du comportement au fluage des Kriechverhaltens von Versickerungsblöcken
structures alvéolaires ultra-légères
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 155.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17151-2:2025 E
worldwide for CEN national Members.

prEN 17151-2:2025 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and units . 5
5 Apparatus . 6
5.1 Compression testing apparatus . 6
5.2 Measuring devices . 6
6 Test sample . 7
6.1 General. 7
6.2 Number . 7
6.3 Age and conditioning . 7
7 Test procedure . 8
7.1 Loads . 8
7.2 Test temperature . 8
7.3 Test procedure . 8
7.4 Test duration . 8
8 Analysis . 8
8.1 Plot strain vs time . 8
8.2 Creep factor . 10
8.2.1 Creep factor at test stress . 10
8.2.2 Strain at specific stress . 10
9 Test report . 10
Annex A (normative) Regression analysis with time as the independent variable . 12
A.1 Principle . 12
A.2 Regression with time as the independent variable . 12
A.2.1 General. 12
A.2.2 Suitability of data . 13
A.2.3 Functional relationships . 13
Bibliography . 14

prEN 17151-2:2025 (E)
European foreword
This document (prEN 17151-2:2025) 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 Enquiry.
prEN 17151 consists of the following parts under the general title Plastics piping systems for non-pressure
underground conveyance and storage of surface water:
— Part 1: Test method for determination of long-term compression strength of boxes
— Part 2: Test method for determination of creep behaviour of boxes (this document)

prEN 17151-2:2025 (E)
Introduction
The test described in this document determines the extent to which thermoplastic units will deform
permanently under the influence of constant compressive stress. Creep occurs as a function of time through
extended exposure to levels of stress that are below the yield strength of the material.
Creep tests are performed in compression at different load levels and the deflection over time is measured.
The load levels are selected to ensure that failure does not occur within the time frame of the test.
The creep tests are carried out by testing a series of samples placed between two stiff plates with different
constant compression loads applied. Deflection is recorded against time. The linear portion of the creep
strain plot can be extrapolated to predict the strain at a given time longer than the test period, normally
dictated by the application design. From these extrapolated curves a creep factor can be obtained.

prEN 17151-2:2025 (E)
1 Scope
This document specifies a test method for determining the compressive creep behaviour of boxes made of
thermoplastic materials intended for use in a modular system for non-pressure underground conveyance
and storage of surface water.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 17150, Plastics piping systems for non-pressure underground conveyance and storage of non-potable
water — Test method for determination of short-term compression strength of boxes
prEN 17151-1, Plastics piping systems for non-pressure underground conveyance and storage of surface
water — Part 1: Test method for determination of long-term compression strength of boxes
EN ISO 7500-1:2018, Metallic materials — Calibration and verification of static uniaxial testing machines —
Part 1: Tension/compression testing machines — Calibration and verification of the force-measuring system
(ISO 7500-1:2018)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply in addition to the terms and
definitions in prEN 17151-1.
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
creep
increase in strain with time when a constant force is applied
[SOURCE: EN ISO 899-1:2017] [1]
3.2
creep factor
strain ratio for a given applied stress and time
4 Symbols and units
For the purposes of this document, the following symbols and units apply.
b initial width of box mm
i
d deflection at time t mm
e e
F force applied kN
h initial height of box mm
i
h height of box after pre-load mm
l initial length of box mm
i
prEN 17151-2:2025 (E)
t time to which test results are extrapolated h
e
γ creep factor for stress level i at extrapolated time -
te,i
ε extrapolated strain at t %
e e
ε strain at extrapolated time for stress level i %
te,i
ε strain at 3 min (0,05 h) for stress level i %
t0,05,i
σ compressive s
...