ISO/FDIS 5091-4

Structural intervention of existing concrete structures using cementitious materials — Part 4: Jacketing

Intervention structurelle sur les structures en béton existantes utilisant des matériaux cimentaires — Partie 4: Chemisage

General Information

• Status: Not Published
• ICS: 91.080.40 - Concrete structures
• Technical Committee: ISO/TC 71/SC 7 - Maintenance and repair of concrete structures
• Drafting Committee: ISO/TC 71/SC 7 - Maintenance and repair of concrete structures
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 26-Apr-2023
• Completion Date: 26-Apr-2023

Standards Content (Sample)

DRAFT INTERNATIONAL STANDARD
ISO/DIS 5091-4
ISO/TC 71/SC 7 Secretariat: KATS
Voting begins on: Voting terminates on:
2022-07-26 2022-10-18
Structural intervention of existing concrete structures
using cementitious materials —
Part 4:
Jacketing
ICS: 91.080.40
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
This document is circulated as received from the committee secretariat.
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
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Reference number
NATIONAL REGULATIONS.
ISO/DIS 5091-4:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
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PROVIDE SUPPORTING DOCUMENTATION. © ISO 2022
---------------------- Page: 1 ----------------------
ISO/DIS 5091-4:2022(E)
DRAFT INTERNATIONAL STANDARD
ISO/DIS 5091-4
ISO/TC 71/SC 7 Secretariat: KATS
Voting begins on: Voting terminates on:
Structural intervention of existing concrete structures
using cementitious materials —
Part 4:
Jacketing
ICS: 91.080.40
COPYRIGHT PROTECTED DOCUMENT
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
© ISO 2022
THEREFORE SUBJECT TO CHANGE AND MAY
This document is circulated as received from the committee secretariat.

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NOT BE REFERRED TO AS AN INTERNATIONAL

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POTENTIAL TO BECOME STANDARDS TO
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NATIONAL REGULATIONS.
Website: www.iso.org ISO/DIS 5091-4:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
Published in Switzerland
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
© ISO 2022 – All rights reserved
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2022
---------------------- Page: 2 ----------------------
ISO/DIS 5091-4:2022(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction .............................................................................................................................................................................................................................. vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 2

3.1 General ........................................................................................................................................................................................................... 2

4 Investigation of existing structure...................................................................................................................................................2

4.1 General ........................................................................................................................................................................................................... 2

4.2 Investigation ............................................................................................................................................................................................. 2

4.2.1 Investigation using documents, records, etc. ........................................................................................... 2

4.2.2 On-site investigation ....................................................................................................................................................... 3

5 Intervention design........................................................................................................................................................................................... 4

5.1 General ........................................................................................................................................................................................................... 4

5.2 Structural plan ....................................................................................................................................................................................... 4

5.3 Structural details ................................................................................................................................................................................. 5

6 Materials ....................................................................................................................................................................................................................... 6

6.1 General ........................................................................................................................................................................................................... 6

6.2 Materials in existing structure ................................................................................................................................................ 6

6.3 Materials used in repairing or strengthening parts ............................................................................................. 6

6.3.1 General ........................................................................................................................................................................................ 6

6.3.2 Cementitious materials ................................................................................................................................................ 7

6.3.3 Reinforcing materials .................................................................................................................................................... 9

6.3.4 Bonding products .............................................................................................................................................................. 9

6.3.5 Filling materials ............................................................................................................................................................... 10

6.4 Characteristic values and design values of materials ...................................................................................... 10

6.4.1 eneral ......................................................................................................................................................................................... 10

6.4.2 Cementitious materials ............................................................................................................................................. 10

6.4.3 Reinforcing materials ................................................................................................................................................. 10

6.4.4 Bonding products ........................................................................................................................................................... 10

7 Actions .........................................................................................................................................................................................................................10

7.1 General ........................................................................................................................................................................................................ 10

7.2 Actions for intervention design ............................................................................................................................................ 11

8 Performance verification for repaired or strengthened structure ...........................................................11

8.1 General ........................................................................................................................................................................................................ 11

8.2 Calculation of response values .............................................................................................................................................. 11

8.2.1 General ..................................................................................................................................................................................... 11

8.2.2 Modeling of structure .................................................................................................................................................12

8.2.3 Structural analysis ........................................................................................................................................................12

8.2.4 Calculation of response .............................................................................................................................................12

8.3 Durability verification ..................................................................................................................................................................13

8.4 Safety verification ............................................................................................................................................................................ 13

8.4.1 General .....................................................................................................................................................................................13

8.4.2 Verification related to failure .............................................................................................................................. 13

8.5 Serviceability verification ......................................................................................................................................................... 16

8.5.1 General ..................................................................................................................................................................................... 16

8.5.2 Verification related to appearance .................................................................................................................. 17

8.5.3 Verification related to vibration ........................................................................................................................ 17

8.5.4 Verification related to displacement and deformation ................................................................. 17

8.6 Seismic performance verification....................................................................................................................................... 17

8.7 Structural details .............................................................................................................................................................................. 18

8.7.1 Arrangement of reinforcing materials and spacing of reinforcing steel ....................... 18

iii
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ISO/DIS 5091-4:2022(E)

8.7.2 Covering and jacketing thickness of reinforcing materials....................................................... 18

8.7.3 Joints for lateral reinforcing materials ........................................................................................................ 19

8.7.4 Anchorage of longitudinal reinforcement to footings .................................................................... 19

8.7.5 Intermediate penetrating tie ................................................................................................................................ 20

9 Construction ..........................................................................................................................................................................................................20

9.1 General ........................................................................................................................................................................................................ 20

9.2 Prior investigation and construction plan.................................................................................................................. 21

9.3 Surface treatment ............................................................................................................................................................................. 22

9.4 Assembly of reinforcing materials ..................................................................................................................................... 22

9.5 Execution of concrete jacketing ........................................................................................................................................... 23

9.6 Execution of mortar jacketing ............................................................................................................................................... 23

9.6.1 Surface preparation ...................................................................................................................................................... 23

9.6.2 Storage, mixing and transportation of jacketing materials ......................................................23

9.6.3 Execution of mortar jacketing ............................................................................................................................. 24

9.6.4 Curing ........................................................................................................................................................................................ 24

9.7 Surface protection ............................................................................................................................................................................ 25

9.8 Quality control ..................................................................................................................................................................................... 25

9.9 Inspection ................................................................................................................................................................................................ 25

10 Records ...................................................................... ..................................................................................................................................................26

11 Maintenance ..........................................................................................................................................................................................................26

Annex A (informative) Examples of execution and design ........................................................................................................27

© ISO 2022 – All rights reserved
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ISO/DIS 5091-4:2022(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

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

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organisation (WTO) principles in the Technical Barriers to Trade (TBT) see

www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 71, Concrete, reinforced concrete and pre-

stressed concrete, Subcommittee SC 7, Maintenance and repair of concrete structures.

A list of all parts in the ISO 5091 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
© ISO 2022 – All rights reserved
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ISO/DIS 5091-4:2022(E)
Introduction

As a repairing and strengthening method, attaching of cementitious material layer to surface of

existing concrete structures has been widely accepted. Since the cementitious layer does not have

enough tensile strength, tension reinforcement is generally placed in the cementitious layer. There are

two types of attaching way. For the first way, the cementitious layer is attached either on top surface

or bottom surface of horizontal concrete members, especially slabs, while, for the second way, the

cementitious layer is attached to jacket vertical concrete members, especially columns. There has not

been ISO standard on design, execution and maintenance for this method with attaching cementitious

layer. This ISO 5091 serves as the first ISO standard for the intervention by attaching cementitious

material layer with tension reinforcement inside.

At the same time, this ISO 5091 is the first ISO standard developed for a specific intervention method,

which conforms to the umbrella code, ISO 16311 Maintenance and repair of concrete structures,

especially ISO 16311-3 – Part 3: Design of repairs and prevention and ISO 16311-4 – Part 4: Execution of

repairs and prevention.

ISO 5091 Structural intervention of existing concrete structures using cementitious materials consists

of four parts; ISO 5091-1 – Part 1: General principles, ISO 5091-2 – Part 2: Top-surface overlaying,

ISO 5091-3 – Part 3: Bottom-surface (soffit) underlaying, and ISO 5091-4 – Part 4: Jacketing. ISO 5091-1

provides the issues common to all three parts, while ISO 5091-2, 3 and 4 provide the issues specific to

each attaching way of cementitious material layers.

It is expected that this ISO 5091 could serve as a practical standard for construction industry, such as

client, design consultant and general contractor, to apply the structural intervention with externally

attached cementitious layer. Additional technical information, which is not provided explicitly in

ISO 5091, needs to be provided in each application case with consideration of the provisions of ISO 5091.

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DRAFT INTERNATIONAL STANDARD ISO/DIS 5091-4:2022(E)
Structural intervention of existing concrete structures
using cementitious materials —
Part 4:
Jacketing
1 Scope

This document specifies the standard requirements regarding design, construction and maintenance

to be applied for structural intervention using the jacketing method, which places reinforcing materials

such as reinforcing steel or FRP grids around the periphery of existing concrete column or beam and

jackets these members with cementitious materials. The requirements not mentioned in the Jacketing

shall be as set forth in ISO / NP 5091-1.

NOTE Jacketing is a construction method that restores or improves mechanical performance, such as flexural

load-carrying capacity, shear capacity and ductility, as well as durability and other performance properties, by

placing reinforcing steel or FRP grids around existing concrete members or in the grooves on the concrete surface

and jacketing the entire periphery of the members with cementitious materials, such as concrete or polymer

hydraulic cement mortar, so that the materials integrate with the existing concrete members. Generally, when

concrete is used as the jacketing material, the concrete jacketing method is adopted whereby concrete is placed

in set up molds, or when polymer hydraulic cement mortar or other types of mortar is used as the jacketing

material, the mortar jacketing method is adopted whereby the thickness of members is increased by spraying or

trowelling. Jacketing is often employed for seismic strengthening mainly of column members such as bridge piers

and beam members of rigid-frame piers. The Jacketing specifies the standard requirements regarding design,

construction and maintenance to be applied for structural intervention of existing concrete structures using the

jacketing method. The requirements not mentioned in the Jacketing shall be as set forth in ISO / NP 5091-1.

NOTE The Jacketing also covers cases of intervention in which the jacketing method is used to repair or

strengthen concrete structures such as reinforced concrete bridge piers damaged by seismic actions. When a

damaged concrete structure is repaired or strengthened using the jacketing method, the status of damage such

as concrete cracking and spalling shall be grasped through a prior investigation and crack injection or sealing,

patching repair and other measures shall be taken in advance as necessary
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 16311-1:2014, Maintenance and repair of concrete structures — Part 1: General principles

ISO 16311-2:2014, Maintenance and repair of concrete structures — Part 2: Assessment of existing concrete

structures

ISO 16311-3:2014, Maintenance and repair of concrete structures — Part 3: Design of repairs and

prevention

ISO 16311-4:2014, Maintenance and repair of concrete structures — Part 4: Execution of repairs and

prevention
ISO 22966:2009, Execution of concrete structures
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ISO/DIS 5091-4:2022(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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 General

The definitions of the terms used in the Jacketing shall be as defined in Clause 3 of ISO / NP 5091-1.

4 Investigation of existing structure
4.1 General

The investigation of the existing structure for which to consider intervention using the jacketing

method shall be conducted as set forth in Clause 4 of ISO / NP 5091-1.

When an earthquake-affected structure is repaired or strengthened using the jacketing method, the

status of damage to that structure shall be studied in detail.

NOTE Jacketing is often employed for seismic strengthening of vertical members such as reinforced concrete

bridge piers. In some cases, it is also used for intervention of earthquake-affected structures. An earthquake-

affected structure may have been suffered from with different types of damage including cracking of concrete,

spalling of cover concrete, crushing of concrete, buckling and rupture of reinforcing steel and so on. Depending

on the status of damage, it may be necessary to take measures such as crack injection or sealing, patching repair,

restoration of deformation of reinforcement and replacement of reinforcement before intervention using the

jacketing method. These types of damage may significantly impact the mechanical performance of the existing

structure and the repaired or strengthened structure. Therefore, when an earthquake-affected structure is

repaired or strengthened using the jacketing method, it is necessary to grasp the status of damage through an

investigation, evaluate the impact that these types of damage have on the performance of the structure by means

of an appropriate method and ensure that the intervention design and construction plan reflect the evaluation

results.
4.2 Investigation
4.2.1 Investigation using documents, records, etc.

A investigation using documents, records, etc. shall be conducted in accordance with 4.2.1 of ISO / NP

5091-1.

Details of the materials used in the target existing structure and the structural specifications shall be

understood from the design documents created at the time of construction, the design documents for

the intervention work performed before the consideration of intervention.

NOTE The structural specifications mean the cross-sectional dimensions and reinforcement arrangement.

These are necessary for evaluating the performance of the existing structure and verifying the performance of

the repaired or strengthened structure.
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ISO/DIS 5091-4:2022(E)
4.2.2 On-site investigation

The on-site investigation on the existing structure shall be conducted in accordance with 4.2.2 of ISO /

NP 5091-1.

NOTE Obtaining the expected effect of intervention through the use of the jacketing method requires

ensuring the integrity between the existing structure and the jacketing parts. It is therefore advisable to grasp

the status of degradation and damage on the surface and inside of the existing structure through the on-site

investigation.

The on-site investigation on an earthquake-affected structure shall involve studying the status of

damage caused by the earthquake in detail.

NOTE An earthquake-affected structure may have been suffered from different types of damage including

cracking of concrete, spalling of cover concrete, crushing of concrete, buckling and rupture of reinforcing steel

and so on. Therefore, when an earthquake-affected structure is repaired or strengthened using the jacketing

method, the status of damage shall be studied in detail by means of an appropriate method. The methods

commonly used in the on-site investigation are visual inspection and tapping inspection.

NOTE It is advisable to grade the changes in the appearance, taking into consideration the degree of damage

to the concrete, steel, etc. and changes in the mechanical performance, and evaluate the structural performance

according to the grading of the appearance changes. In the structural performance evaluation based on the

appearance changes, the grades of structural performance shall be established on mechanical grounds taking

into full consideration the degree of each graded appearance change and the impact of the changed region on

structural performance. Appearance changes may be classified into the following three grades.

— Grade I: No or minor damage
— Grade II: Moderate damage
— Grade III: Severe damage

The mechanical resistance of the change region should be classified into the following 4 levels.

— Level a: Resistance remaining intact
— Level b: Slightly degraded resistance
— Level c: Significantly degraded resistance
— Level d: No resistance

NOTE As for reinforced concrete bridge piers damaged by an earthquake, the methods of inspecting the

damaged bridge piers and determining the degree of damage should be set properly. In the case of reinforced

concrete bridge piers, both the position and degree of damage are important. It is, therefore, necessary to

investiga
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