Our auscultation and testing expertise include non-destructive testing (NDT) methods and destructive or semi-destructive tests carried out in the field are essential diagnostic tools.
These methods provide a better understanding of the structure, detect weaknesses and quickly assess the quality of mechanical, electrochemical and physicochemical properties of materials. They also estimate the extent, intensity and kinetics of degradation and identify pathologies affecting the structure.
Structure radar, ground penetrating radar (GPR) and pachometer
These methods, which are based on the propagation of electromagnetic waves, are primarily used to detect reinforcement in concrete. They can be used to determine the position of passive reinforcement and measure the thickness of the concrete cover in reinforced concrete elements. For prestressed concrete structures, they can be used to reconstruct the layout of the cables.
Corrosion potential, corrosion rate and electrical resistivity of concrete
These electrical and electrochemical methods are used to evaluate the level of corrosion protection of the reinforcing steel within the concrete. They enable corrosion zones to be located and the intensity and kinetics of corrosion to be determined. When combined with laboratory tests on concrete samples, these methods can be used to evaluate the concrete’s ability to provide long-term corrosion protection for reinforcement.
US measurements, 3D tomography, acoustic admittance and impact echo
Ultrasonic methods applied to concrete are based on the propagation of longitudinal (P) or shear (S) waves. These methods are primarily used to characterise the homogeneity of concrete and to detect internal defects in large components. Applications include measuring crack depths, determining material thicknesses, locating voids or delamination planes, and detecting the position of prestressing ducts. Some techniques can achieve investigation depths of around 2 metres.
Infrared thermography
The thermal inspection methods used for buildings and bridges are primarily based on infrared thermography. Using a thermal camera, it is possible to detect the position of networks inside a heated floor, check the quality of composite material bonding or identify defects in waterproofing applications. Although the cameras are easy to use, interpreting the resulting thermograms remains a task for specialists.
Centre hole method (ASTM E837-20)
This method is based on the principle of stress relief and is also known as Centre Hole Drilling (CHD). Gauges are positioned at 120° around the future centre hole, and stresses are released by drilling a small-diameter, shallow hole at a controlled speed in stages. Removing the stressed material during drilling causes the surrounding material to adjust its stress state to restore equilibrium.
Opposite: an example of an HBM strain gauge rosette for the centre hole method.
Slotstress
Slotstress helps you to understand the distribution of loads within a structure, enabling you to verify its structural resistance and long-term service load trends. During its service life, the forces and stresses within a structure can change due to variations in loads and the structure’s natural ageing process. These stresses may then become incompatible with the use criteria or pose a risk to the structure’s safety.
Slotstress therefore enables engineers to implement optimised maintenance or reinforcement strategies.
We carry out static and dynamic tests on engineering structures in accordance with professional recommendations. Each assignment is based on a rigorous protocol involving modelling and determining load cases, installing instrumentation, monitoring the structure during loading and analysing its behaviour.
These tests allow us to validate compliance, refine calculations and authorise commissioning. We work on new, existing or renovated structures for public and private clients. Each test is documented in a comprehensive report that can be used immediately.
Operational Modal Analysis (OMA) involves measuring the natural vibrations of a structure in operation, for example those caused by wind or traffic. This allows the dynamic behaviour of a structure to be analysed without the need for heavy and costly testing.
When regular measurements are taken, this technique can be used to monitor changes in a structure’s condition and anticipate maintenance requirements.
Follow-up of structures state of health by vibration monitoring
Our global structural monitoring solution Build’Health allows you to: