ISO 22873:2021

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 22873
ISO/TC 71/SC 6
Quality control for batching and
Secretariat: JISC
mixing steel fibre-reinforced
Voting begins on:
2021­01­23 concretes
Voting terminates on:
2021­03­20
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Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 22873:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
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©
NATIONAL REGULATIONS. ISO 2021

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ISO/FDIS 22873:2021(E)

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ISO/FDIS 22873:2021(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Materials . 2
4.1 Steel fibres . 2
4.1.1 Classification . 2
4.1.2 Shape . 2
4.2 Admixture . 2
4.3 Storage of fibres . 2
5 Mixture proportioning . 3
5.1 General . 3
5.2 Proportioning methods . 3
6 Batching . 3
6.1 Measuring materials. 3
6.2 Batching plant . 3
7 Mixing. 3
7.1 General . 3
7.2 Mixer equipment . 4
7.3 Mixing method . 4
7.3.1 Add fibres to transit mix truck . 4
7.3.2 Add fibres to aggregate on a conveyor belt . 4
8 Quality . 5
8.1 Slump and air content . 5
8.2 Tolerances in slump . 5
8.3 Tolerances in air content . 5
Bibliography . 6
© ISO 2021 – All rights reserved iii

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ISO/FDIS 22873:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 71, Concrete, reinforced concrete and pre-
stressed concrete, Subcommittee SC 6, Non-traditional reinforcing materials for concrete structures.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv © ISO 2021 – All rights reserved

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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 22873:2021(E)
Quality control for batching and mixing steel fibre-
reinforced concretes
1 Scope
This document specifies the principles and procedures to secure quality control of steel fibre-reinforced
concretes (SFRC) during batching and mixing procedures to deliver to a purchaser with the ingredients
uniformly mixed, and that can be sampled and tested at the point of delivery.
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.
ISO 13270, Steel fibres for concrete — Definitions and specifications
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13270 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
slump
distance from the top of the slumped concrete to the level of the top of the slump cone.
3.2
workability
property measure of the ease of moulding or shaping an unshaped concrete.
3.3
segregation
separation of aggregate and fines during fabrication of a concrete to leave a honeycomb appearance
and/or a layer of excess fines.
3.4
fibre balling
bunch of fibres sticking together during fibre integration in the concrete mix.
3.5
steel fibres
straight or deformed pieces of cold-drawn steel wire, straight or deformed cut sheet fibres, melt
extracted fibr
...