Materials diagnostics and sustainability engineering

Structures can be affected by ageing-related problems and material damage, which can reduce their level of service, compromise user safety, and potentially lead to premature collapse.

Materials diagnostics allow us to identify the cause of issues, evaluate their severity and potential progression, and design effective, sustainable solutions.

Following a preliminary diagnostic phase involving an analysis of the problems encountered, our experts design and tailor diagnostic programmes based on on-site investigations, such as inspections, measurements and sampling. These programmes may be supplemented by laboratory tests, including mechanical, physical-chemical and petrographic analyses.

Based on the diagnostic results, our specialists will advise and support you in developing effective repair and maintenance strategies to extend the service life of your structures.

Some areas of expertise:

Diagnosis of corrosion in reinforced concrete reinforcement

Diagnosis of a reinforced concrete structure damaged by reinforcement corrosion must determine the cause and extent of the corrosion. This process involves collecting all the necessary data to make repair recommendations that align with the client’s durability requirements. The aim is to study different repair strategies and ultimately select the most suitable technical and economic solution from a range of options.

Corrosion diagnosis comprises three main phases:

On-site investigations, including visual inspection, auscultation (see our dedicated tools), and concrete sampling
Laboratory analyses and tests (see specific tests)
The final phase involves determining the condition of each part of the structure and recommending a repair strategy tailored to the operational and durability requirements

Diagnosis of internal swelling reactions in concrete (RSI, RAG)

Concrete structures suspected of being affected by internal swelling reactions (ISR) require a specific diagnosis. This diagnosis should enable the origin of the problems to be determined, a prognosis of their likely development to be established, and appropriate treatment and monitoring solutions to be proposed.

Diagnosis of concrete suspected of triggering an Alkali-Aggregate Reaction (AAR) or an Internal Sulphate Reaction (ISR) involves the following steps:

initial assessment and information gathering
record of defects and establishment of a reference system for monitoring trihedral-type cracking
concrete sample collection and laboratory testing (see specific tests)
identification of the nature of the reaction (GRAR and/or ISR) and determination of its expansion potential
assessment of the consequences for the structure, if necessary by modelling the evolution of the swelling and determining the associated loss of resistance
recommendations on actions to be taken in terms of monitoring or works

Post-fire diagnosis of reinforced or prestressed concrete structures

Diagnosing a structure damaged by fire (e.g. a building, tunnel or bridge) is an essential step in optimising the repair work required to enable the structure to be put back into service. This requires a precise assessment of the damage’s severity and extent, as well as the residual mechanical characteristics of the materials (concrete and passive and/or active reinforcement).

The following steps are involved:

initial assessment of the situation and definition of immediate safety measures
survey of apparent damage and state of deformation of the structure
non-destructive testing (NDT) is used to distinguish between sound and damaged areas, and samples are taken (e.g. concrete, reinforcement)
determination of the temperatures reached in the focal area and assessment of the residual mechanical characteristics of the materials
definition of repair and/or reinforcement work on the structure

Diagnosis of embankments reinforced with metal elements of the Terre Armée type

Reinforced earth structures, such as retaining walls and bridge abutments, are sensitive elements of road infrastructure and are subject to specific monitoring and assessment procedures.

Sixense can support you throughout the diagnostic process:

risk analysis and definition of the inspection programme
assessment of the corrosion status of reinforcements by extracting durability samples, excavating or sampling reinforcements from the facing
laboratory analyses and tests: determination of the mechanical characteristics of the reinforcement; assessment of the residual thickness of the galvanisation; and assessment of the aggressiveness of the backfill material
diagnosis and recommendations for monitoring and managing structures

Find out more about our tools

Auscultation and Testing

Materials Laboratory

A chain of expertise mastered from start to finish

On-site assessment of pathologies

and the severity and stage of the disorder

Monitoring conditions over time

modelling, accelerated ageing in the laboratory, auscultation and monitoring

Treatment solutions

design, programming, monitoring and control of implementation