Projects
Road embankment strengthened with concrete column
Historical post-tensioned bridge over Motława river
Railway line above the substrate strengthened with slurry walls
Teeth-shaped cable anchorage during its tensioning in steel truss bridge
Smart composite components for FRP bridge engineering
Research on composite wind turbine blade for bridge applications
Steel ground anchorages in an axial tension test
Fatigue strain measurements in different layers of a road structure
Monolithic vs. layered – the first such comparison in RC structures
The second bridge in Germany equipped with embedded DFOS Nerve-Sensors
Museum of Modern Art: load tests of large-diameter piles
The project is one of the most prestigious investments built in the heart of Poland’s capital. Museum of Modern Art is a structure with unique design, built close to existing infrastructure. Foundations include deep large-diameter piles equipped with EpsilonRebars for safety reasons. Measurements were done during load tests and allowed for detailed analysis of piles structural performance and force transfer to the surrounding ground.
One of the largest concrete bridge in Poland – crack detection
EpsilonRebars had been chosen for this project as the best solution dedicated to crack detection and estimation of their width changes. Four sensors were installed in the pylon’s horizontal beam, supporting the deck slab. In this case, a near-to-surface installation method was applied (grooves) to provide appropriate integration of EpsilonRebars with the existing concrete and to create natural protection against the environmental impacts.
Foundation monitoring within the ’Central Point’ skyscraper
Nowadays, spectacular skyscrapers are built in the centres of large cities. This project refers to a structure located in the centre of Warsaw. Due to the proximity of the surrounding infrastructure, it is very important to monitor the interaction of the foundations with the ground during the entire construction (raising the subsequent floors). That is why EpsilonRebars were chosen to control Strains and cracks both in deep barrette piles as well as the foundation slab.
The first bridge in Germany equipped with embedded DFOS Nerve-Sensors
EpsilonRebars and EpsilonSensors were integrated (embedded) inside the steel-concrete bridge, which is the first such type of smart bridge in Germany. The DFOS-based monitoring system was designed to provide the possibility of analysing strains in concrete, in steel reinforcing bars, as well as to detect all the microcracks and calculate vertical displacements (deflections). Also, additional distributed temperature measurements were applied for appropriate thermal compensation.
High pressure gas pipeline: measure-ments of safety-critical structure
EpsilonRebars and EpsilonSensors were integrated (embedded) inside the steel-concrete bridge, which is the first such type of smart bridge in Germany. The DFOS-based monitoring system was designed to provide the possibility of analysing strains in concrete, in steel reinforcing bars, as well as to detect all the microcracks and calculate vertical displacements (deflections). Also, additional distributed temperature measurements were applied for appropriate thermal compensation.
Idustrial tower in the largest mining tailings reservoir in Europe
Żelazny Most Reservoir is the largest reservoir for copper mining tailings in Europe, owned by KGHM Polska Miedź. It was put into exploitation on February 12, 1977. There are four industrial overflow towers on the site. One of them in 2018, was equipped with vertical 3DSensors to monitor temperatures and horizontal displacements. One of the reasons for DFOS-based monitoring system installation was the construction of the tower’s new floors.
Sewer concrete collector during its strengthening with GRP panels
The concrete sewage collector was constructed in 1964 and is now reinforced with Glass-fiber Reinforcement Plastic (GRP) panels. EpsilonRebars (ER) and the EpsilonSensor (ES) from the Nerve-Sensors family were installed inside the near-to-surface grooves to verify the strengthening process. ERs were placed longitudinally over the entire 150 m long section, while ES was installed in selected key circumferences. The system allowed for detailed analysis of strains, cracks, displacements and temperatures.
24 m long prestressed concrete girders as a part of the smart production hall
Three 24 m long prestressed concrete girders were quipped with EpsilonRebars embedded inside. The sensors were delivered on-site in coils and tightened to the existing reinforcement. This fast and easy installation process allowed the creation of smart elements able to self-diagnose during all stages: concrete hardening, prestressing, mounting in the structure, as well as during the load tests. Currently, the girders are under continuous operation in one of Polish production halls.
EpsilonRebars as a Nervous System of hybrid footbridge in Nowy Sącz
EpsilonRebars in the form of composite rods, being simultaneously the structural reinforcement for the concrete deck, were placed along the entire footbridge span of nearly 80 m. Thanks to the application of distributed optical fibre sensing technique, it was possible to perform measurements of strains, cracks, displacements (deflections) and temperatures during the hydration of early-age concrete (thermal-shrinkage strains) as well as during the load tests.
Vertical displacements of the ground around footing being pulled out
This project aimed to determine the potential slip plane that occurred during the concrete footing pullout. For this purpose, 3DSensors (DFOS displacement sensors) were installed around the structure in two planes, and vertical displacements were measured. Thanks to the cutting-edge technology of 3DSensors, an advanced analysis of the interaction between the footing and the surrounding ground were possible without any distortions and reinforcing effect in the ground.
Displacements of a road embankment above the strengthened substrate
Within this project, two 3DSensors were installed along a road embankment to measure its vertical displacements. Two independent lines of 3DSensors, each 48 m long, were provided, together with multiple reference measurement techniques: longitudinal and transverse inclinometers, spot tiltmeters and geodetic benchmarks. Vertical displacements were measured in a distributed way with 3DSensors and compared with the results of reference methods.
Cable-stayed bridge: localised effects due to the steel anchorage
The steel cable-stayed bridge in Przemyśl was put into the service in 2012. At the time of construction, it was the fourth highest bridge in Poland. It is supported by two 61.5 meter high pylons, and its total length (inc. overpasses) is equal to 530 m. In 2017, the bridge was equipped with distributed fibre optic sensors (DFOS) dedicated for strain and temperature measurements. Two measurement sections were installed in collaboration with university graduate students.
Strains and displacements at the base of a road embankment
The road embankment was designed above the substrate, strengthened with concrete columns. The transmission layer between the columns and earth body of the structure was equipped with Nerve-Sensors: EpsilonRebars (ER) and 3DSensors for measuring strains and vertical displacements respectively. A total number of 16 sensors were installed both in longitudinal and transverse directions. Furthermore, the sensors were used for simultaneous measurements of temperatures.
Strains in composite reinforcement at the base of a road embankment
In the present case study, the base of the road embankment was reinforced by composite rebars in two directions. This solution is favourable in the context of durability due to the high resistance of composites to corrosion. Some of the bars were replaced with EpsilonRebars, which now have a double function in the structure: both sensing and reinforcing. Two measurement layers also allowed for the calculation of vertical displacement profiles.
The highest road embankments in Poland – temperature measurements
To monitor the structural behaviour of the largest road embankments in Poland, we applied three independent measurement solutions: Inclify, SHMProfiler and EpsilonRebars from Nerve-Sensors. The latter were used to measure temperature distributions at the base along the entire width of the structure. Temperature results were used, among other things, to compensate for data from the two other measurement techniques.
Steel-concrete railway bridge: strains and cracks during load tests
The composite (steel-concrete) bridge in Dąbrowa Górnicza was designed according to a new approach and put into the service in 2019. This is why verification of its structural performance under real operating conditions was of significant importance. The bridge was equipped with DFOS strain sensors, installed both on the concrete and steel surfaces. The measurements during load tests allowed for detailed analysis of the deformation state, including the detection of all microcracks.
Strains and displacements in asphalt layers: static load tests & SHM
This project involved two types of road surface structures equipped with Nerve-Sensors, measuring both strains (EpsilonRebars) and displacements (3DSensor). All of them were embedded into the road layers during its construction, providing the possibility of analyzing its internal structural behaviour under static proof load tests. Our nervous system, supplemented by spot temperature sensors, was used successfully also in terms of long-term structural health monitoring (SHM).
Strains and displacements in asphalt layers: dynamic load tests
This project involves two types of road surface structures equipped with Nerve-Sensors, measuring both strains (EpsilonRebars) and displacements (3DSensor). All of them were embedded into the road layers during its construction allowing for analysis of its internal behaviour under dynamic load tests (truck’s runs). Our system was successfully applied for analysing the structural response in real time, including all dynamic effects registered using high-frequency mode.
Strains and cracks in a new type of slurry wall: research field (1)
The subject of the project was the slurry wall made of a new type of material: fibre-reinforced concrete mixed with the ground. As this technology must be carefully checked before use, the EpsilonRebars were used for this purpose. The structural performance of the wall was monitored during deepening of the excavation area as well as load tests. Thanks to Nerve-Sensors, it was possible to detect cracks and fractures invisible to other techniques.
Strains and displacements in a new type of slurry wall: research field (2)
The subject of the project was a slurry wall made of a new type of material: fibre-reinforced concrete mixed with the ground. As this technology must be carefully checked before use, EpsilonRebars were used for this purpose. The structural performance of the wall was monitored during the deepening of the excavation as well as during the mechanical load tests. Thanks to Nerve-Sensors, it was possible to detect cracks but also to calculate horizontal displacements.
Concrete column-slab system: simulation of column failure
The performance of a full-scale concrete structure was investigated during the simulation of column failure. EpsilonSensors were installed inside the slab by tightening to the existing reinforcement. The main aim was to observe the crack morphology. Additional optical fibres were glued to the steel reinforcement to analyse its behaviour during the yielding process. The Nerve-Sensor system measured strains successfully during the entire research until the planned structural failure.
„Concrete tomograph” – early-age behaviour of massive element
The very challenging experiment was a concrete cube equipped with embedded optical sensors in three directions XYZ. The total number of 75 sections for strain and 25 sections for temperature measurements were created without disturbing the structural performance of the concrete. The research aimed to analyse the spatial behaviour of the massive element during the hydration and shrinkage process, including temperatures and heat transfer.
Concrete slab strengthened with FRP composites: strains & cracks
The reinforced concrete slabs were investigated in laboratory conditions in mechanical four point bending tests. Some were strengthened with FRP material to analyse this solution’s effectiveness. However, the application of FRP prevented visual inspection of cracks. That is why all the slabs were equipped with distributed optical fibre strain sensors placed in-between the concrete and the strengthening material, which allowed for the detection of all cracks invisible to the naked eye.
Steel girders during mechanical load tests: elastic and plastic strains
A number of steel girders designed for bridge applications were investigated in laboratory conditions during mechanical tests. The research includes MCL girders as well as I- and H-beams. The challenge in this project was to measure extremely high strains, exceeding the range of elastic behaviour significantly. Thanks to DFOS strain sensors, it was possible to analyse the yielding process up to 20 000 µε in tension and 10 000 µε in compression.
100 m long section of smart highway reinforced with composite bars
The project involves a 100 m long section of a highway in Poland, which was reinforced with only composite bars, including EpsilonRebars from the Nerve-Sensors family. The entire experimental section was concreted without any dilatations, which is a pioneering approach in road engineering. Our DFOS-based monitoring system provided essential information on strain profiles and crack morphology, while also becoming structural reinforcement.
Concrete cylinders – mechanical tests in laboratory conditions
Nerve-Sensors provide new tools for structural analysis of small-size laboratory specimens made of concrete. In this case, 20 standard cylinders were investigated in mechanical axial compression tests up to their failure. DFOS strain sensors allowed for measurements of both compression (longitudinal) and tension (circumferential) strains at the same time. Thanks to the unique data, advanced structural analysis was possible.
Experimental prestressed concrete truck scale platforms
Three 8 m long prestressed concrete truck scale platforms were quipped with EpsilonRebars embedded along the main tendons both in the lower and the upper part. DFOS strain sensors were installed on both surfaces after concrete hardening. The structural performance of the slabs was investigated during all critical stages, including thermal-shrinkage strains of early-age concrete, prestressing & activation of dead weight and finally, during mechanical bending tests.
CFA concrete column: strains & shape analysis during mechanical load tests
The subject of the project was to analyse strain distributions in CFA concrete columns during their hydration (early-age concrete) as well as during mechanical load tests. EpsilonRebars were used for this purpose. Because there was no reinforcement inside the columns, a special mounting process had to be designed and implemented. Nerve-Sensors allowed for detailed assessment of columns’ technical conditions along their entire depth.
Smart composite FRP panel for bridge engineering
In this unique project, it was possible to create a smart element capable of self-diagnosis. Nerve-Sensors, including full integration of optical fibre with composite core, as well as displacement (shape) calculation, was implemented in a single bridge panel dedicated for smart bridge engineering. Many laboratory tests with both strain and displacement measurements were performed under the control of independent reference techniques.
Anchorage zone in 57-year-old post-tensioned precast girder
Ageing infrastructure is a growing problem in many countries, making it a challenge to take optimal decisions for their further safe operation. Therefore, effective diagnostic solutions are being sought, enabling reliable technical condition assessments. The case study presents the results of static and dynamic DFOS strain measurements of a 57-year-old girder dismantled from one of the production halls. Nerve-Sensors were successfully applied for this purpose.
Famous University Bridge in Bydgoszcz: anchorage zone yielding
After seven years of operation, University Bridge in Bydgoszcz became famous because of its structural failure. Significant deformations of the steel anchorage plates beyond the elastic range were identified. All the cables were relieved and then prestressed again after strengthening. Nerve-Sensors were used to monitor this process and identify the safety-critical areas most probable to yield. Now, this unique and essential to the city bridge came back to regular operation.
Gdański Bridge in Warsaw: DFOS-based monitoring of a historical monument
The Gdański Bridge is a six-span steel truss bridge, 406.5 m long and 17 m wide, across the Vistula River in Warsaw. It was opened in 1959 after three years of construction. Its characteristic features are two decks: the upper for road traffic and the lower for trams. EpsilonSensors from the Nerve-Sensors family were selected and installed on the bridge (surface installation with an appropriate adhesive) to monitor the structural performance of safety-critical steel elements.
Prestressed concrete beams working in the extreme large crack state
Prestressed concrete beams, equipped with EpsilonSensors, were investigated during prestressing and mechanical load tests. Twelve beams were made to provide statistical confidence about the obtained results. One EpsilonSensor was arranged in such a way to create four measurement sections at different beam heights. Thanks to that approach, it was possible to detect cracks and calculate their widths, but also to assess the crack depths depending on the load step.
Strains measurements in asphalt layers during dynamic truck runs
This experimental project involved a road structure equipped with EpsilonRebars for strain measurements. Our sensors provided the unique possibility of analysing the internal behaviour of asphalt layers under dynamic truck’s runs. The measurements were done in real-time with extremely high spatial resolution and extreme accuracy. This was due to the high elastic composite core, monolithic design and perfect bonding of the sensors with surrounding asphalt.
Strain measurements in asphalt layers during dynamic truck runs
This experimental project involved a new type of road with a foam-concrete substructure. EpsilonRebars were used to monitor structural response on mechanical load tests. Thanks to the appropriate installation methods, it was possible to provide measurements not only along the horizontal sections but also along with the vertical ones. It’s worth noting that there was no reinforcement facilitating the installation within the entire structure.
DFOS monitoring of an active road located within mining area
EpsilonRebars were integrated (embedded) inside the asphalt layer of a real road structure running in mining areas, i.e. where very large deformations are expected. A new road's structural performance was first investigated during shot-term mechanical load tests. They were performed a few times over the year analyse temperature influence. However, the DFOS-based nervous system will also be a useful diagnostic system for long-term monitoring.
Steel truss bridge with concrete slab with embedded Nerve-Sensors
EpsilonRebars with lengths of 60 m and 90 m were installed within two similar steel truss bridges, crossing the Noteć River in Poland. Nerve-Sensors were embedded inside the concrete slabs over their entire length. They were delivered on-site in coils and secured to the existing reinforcement along the main prestressing tendons. The designed and implemented nervous system of the structure is a perfect solution for both short-term load tests and long-tem monitoring.
Smart composite pipelines capable of DFOS-based self-diagnosis
Composite collectors and pipelines were investigated in collaboration with the Warsaw University of Technology. The specimens were equipped with surface-mounted optical fibres for internal and external strain measurements. Thanks to that approach, 3DSensor could be utilised to calculate displacements (shape changes) expressed directly in millimetres. The research included pipe specimens with different geometry of the cross-section.
Renovation and monitoring of the historical brick masonry walls
This unique research was performed at the Cracow University of Technology. Even though it was a laboratory test, the lessons learned will be beneficial during the monitoring and maintaining the real brick masonry walls of the barracks located in Auschwitz Birkenau camp. Thus, the project is of significant historical meaning. DFOS strain sensors were used to monitor the wall response (built with all imperfections corresponding to the actual state) during mechanical load tests.
Strain and displacement monitoring inside a road structure
EpsilonSensors and 3DSensors were used to create embedded nervous systems in a test environment, simulating the structural behaviour of the actual road substructure. Both longitudinal and transverse sections were investigated at two levels. Despite many sensors installed inside the box, they were not acting as reinforcement and thus, they did not influence the response of the substructure. Strains and displacements were measured at the same time during mechanical loading.
EpsilonSensor and 3DSensor used in a composite deck
The innovative foot deck was designed and implemented within an existing bridge in Rzeszów. DFOS fibres were integrated within the composite panels during their production (infusion), so sensors became an integral part of the entire structure. Appropriate fibres arrangement and their full integration inside the composite panels allowed us to utilise the idea of both strain sensing with the EpsilonSensor and vertical displacement sensing with 3DSensor. The ready-to-use smart panels were delivered on-site.
The first Polish full composite bridge with DFOS-based monitoring system
The innovative DFOS-based monitoring system was applied within the first Polish full composite bridge (composite girders + composite slabs). DFOS strain fibres were installed on the surface in the production hall, and then pre-prepared smart elements were delivered on-site. The system’s design, including the appropriate arrangement of the fibres, allowed us to utilise the idea of both strain sensing with the EpsilonSensor and vertical displacement sensing with the 3DSensor.
Cable-stayed bridge in Rzeszów: steel girder as a displacement sensor
The T. Mazowiecki cable-stayed bridge in Rzeszów was put into service in 2015. The bridge is 482 m long, with two traffic lanes in each direction. The structure is supported by a 107-m long A-shaped pylon with 64 cables. In 2018, the bridge was equipped with distributed fibre optic sensors for strain and temperature measurements. One of the main aims was to create the displacement 3DSensor from the steel girder itself along the 150-metre long river span.