Concrete Repair According to the new European Standard EN 1504

Er. Devinder Chawla Managing Director

European standard EN 1504 The European standard EN 1504 is entitled: Products and

systems for the repair and protection of concrete structures.

EN 1504 is aimed at all those involved with the repair of concrete.

For the first time in the industry, EN 1504 deals with all aspects of the repair and / or protection process including: – definitions and repair principles; – the need for accurate diagnosis of deterioration causes before

specification of the repair method; – detailed understanding of the needs of the client; – product performance requirements and test methods; – factory production control and evaluation of conformity,

including CE marking – site application methods and quality control of the Works

EN 1504 – The Documents The European Standards EN 1504 consist of 10 parts.

PARTS OF BS EN 1504

• Protection, repair and reinforcement (i.e. rehabilitation) of concrete structures requires relatively complicated design, dimensioning and control. The series of CEN standards under EN 1504 defines the principles of rehabilitation of concrete structures, which are damaged.

• These standards specify guidelines for the choice of repair materials and systems that are appropriate for rehabilitation and maintenance of concrete structures. These standards describe the main points of rehabilitation of a damaged concrete structure:

• Assessment of the registered state of a concrete structure

• Determination of the courses of damage

• Determination of the objective of the rehabilitation of a damaged concrete structure concrete structure or its members

• Specification of requirements for the maintenance that should always follow rehabilitation of a damaged concrete structure or its members.

IMPORTANCE OF BS EN 1504

EN 1504 -REVIEW

• Part 1 only reports introductory definitions, while Parts 8 and 10 concern quality control and site application.

• Parts 2-7 describe the products and systems suggested for the repair and protection of the concrete structures.

• Part 9 reports the general principles and the methods for the use of such products and systems.

Design Philosophy - Specifying to BS EN 1504

Part 9 of BS EN 1504 outlines a structured approach to the investigation of the causes of defects in concrete and explains the 11 Principles of remedial action which clients and designer/specifiers should use to prepare their specification.

The system of options, principles and methods is the basis for the selection of products and Designers can make optimal use of the repair principles to find the most appropriate action taking into account health and safety, structural and environmental factors.

BS ENV 1504-9 General Principles for the Use of Products and Systems

BS DDENV 1504 defines the principles for protection and repair of concrete structures which have suffered or may suffer damage or deterioration

The standard also provides guidance on the key stages in the repair and protection process 1. Assessment of defects 2. Identification of the causes of defects 3. Objectives of protection and repair 4. Selection of the appropriate principles and methods 5. Properties of products and systems (1504 parts 2-7) 6. Maintenance management

ENV 1504, Part 9 – Basic considerations

• This part of the EN 1504 specifies the basic principles which shall be used, separately or in combination, where it is necessary to protect or repair concrete structures, above or below ground or water.

• Successful repair of a structure starts with a correct condition assessment and identification of the cause of degradation. All other stages in the repair and protection process depend on these matters.

• The methods for the repair and protection of concrete structures detailed in ENV 1504, part 9 are grouped in 11 principles which relate to

– degradation of the concrete matrix, or

– defects caused by reinforcement corrosion membranes

The 11 Principles for concrete repair and rehabilitation (BS EN 1504-9 )

SKETCH SHOWING ALL 11 PRINCIPLES AT ONE LOCATION

Systematics of planning according to EN 1504-9

FLOW CHART FOR REPAIR

Decision Making Tree

The phases of repair projects

Structural and Non-structural repair (BS EN 1504-3)

Range of different mortars has been developed to provide appropriate solutions to the wide variety of problems resulting in defective concrete. These pre-bagged single component products are available in the 4 different classes specified in BS EN 1504 for structural and non structural concrete repair products:

This basic classification is by compressive strength, however additional test data is required for each product depending on the application for which it is being used.

Repair Mortar Classification

4 Classifications

• Class R1 – Non Structural

• Class R2 – Non Structural

• Class R3 – Structural

• Class R4 – Structural

CONCLUSIONS AND OUTLOOK A new European standard on protection and repair of concrete structures has been worked out, based on the actual state of knowledge regarding the properties of the products, the principles for the use of the products, application and quality control. Parts 2 to 7 regulate the performance of the products and systems for protection and repair of concrete structures with respect to CE marking. The use of the products is based on a logical sequence consisting of options (repair strategies), repair principles and repair methods, which are listed in tables in part 9 of EN 1504. This scheme ensures that suitable products are selected based on the requirements of the practical case. This new series of standards has already replaced all the existing national standards in Europe from JAN 2009 and that it will also have significant impact for other countries also.