ISO 13180-1:2026

International
Standard
ISO 13180-1
First edition
Fibre-reinforced cementitious
2026-05
composites (FRCCs) — Direct tensile
test method —
Part 1:
Strain hardening FRCCs
Composites à base de ciment renforcés par des fibres — Méthode
d'essai de traction directe —
Partie 1: Composites à base de ciment renforcés de fibres à
durcissement sous contrainte
Reference number
© ISO 2026
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Test specimens . 2
5.1 Geometry .2
5.2 Fabrication of specimens .4
6 Test equipment . 5
6.1 General .5
6.2 Testing machine . .5
6.3 Testing setup .5
6.4 Measurement devices .5
7 Test procedure . 5
7.1 Preparation of specimens .5
7.2 Installation of specimens .5
7.3 Test procedure .5
8 Evaluation of test results . 5
8.1 Tensile stress versus strain curve.5
8.2 Stress .6
8.3 Strain .6
8.4 First cracking point .6
8.5 Number of cracks .6
9 Assessment of the tensile test . 6
10 Test report . 6
Bibliography . 8

iii
Foreword
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stressed concrete, Subcommittee SC 6, Non-traditional reinforcing materials for concrete structures.
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iv
Introduction
Strain hardening fibre-reinforced cementitious composites (FRCCs) have been demonstrated to have
superior tensile strength, ductility, energy absorption capacity and fracture toughness compared to normal
concrete. Strain hardening FRCCs include high performance fibre-reinforced cementitious composites
[1,2] [3,4]
(HPFRCCs) , engineered cementitious composites (ECCs) and ultra-high-performance fibre-reinforced
[5-9]
concretes (UHPFRCs) . The superior mechanical and material resistance of strain hardening FRCCs
compared to normal concrete and strain softening FRCCs have motivated structural engineers to apply
[6,7,9,10]
them to civil infrastructure and buildings .
Strain hardening is defined as the material behaviour observed over a specified tensile strain range
following the initiation of cracking, in which the initial peak stress decreases or nonlinear behaviour begins,
and the tensile stress subsequently increases to a value exceeding the initial cracking strength. Within
the defined strain range, strain hardening is characterized by a monotonic increase in tensile stress with
increasing strain. Local stress fluctuations or oscillations are not considered to satisfy the definition of
strain hardening unless they are explicitly permitted and technically justified. This definition is intended to
ensure an objective interpretation of test results and to enable clear identification of the peak tensile stress
associated with strain-hardening behaviour.
The use of strain hardening FRCCs is highly expected to enhance the mechanical resistance of infrastructure
and buildings especially under extreme loads including earthquakes, impacts and blasts. Moreover, the
smaller width of multiple micro cracks of strain hardening FRCCs compared to that of normal concrete
and strain softening FRCCs is expected to enhance the durability of structural members and eventually to
lengthen the service life of infrastructure and buildings.
However, the use of strain hardening FRCCs is still very limited even though there have been increasing
applications of those strain hardening FRCCs. The reasons for limited applications of strain hardening
FRCCs are the absence of International Standard test methods and design codes in addition to the high cost
[10]
of strain hardening FRCCs versus normal concrete . Current ISO standards such as ISO 19044, ISO 21022
and ISO 21914 are applicable for evaluating the uniaxial and biaxial flexural behaviour of FRCCs, but not the
uniaxial tensile response of strain hardening FRCCs.
Although many research papers have reported direct tensile stress versus strain response of various
HPFRCCs, ECCs and UHPFRCs, the responses were obtained from the specimens with different geometry
[4,7]
and different test setups . Consequently, it is difficult to quantitatively compare the tensile resistance of
various strain hardening FRCCs for the purpose of design consideration without standard test methods.
The test method defined in this d
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