Fiber-Reinforced-Polymer Smart Composite Bridge Deck

A demonstration of FRP -- modular solution for the future of road infrastructure

Fiber reinforced polymer vehicular bridges and its components are a sustainable solution to the nation’s crumbling infrastructure

With built in sensors, this “smart” bridge can be monitored throughout its lifecycle to ensure stability and performance

This privately funded infrastructure is project aimed at demonstrating fiber-reinforced-polymer composite materials, or FRPs, as a fast and easy sustainable solution for improving the thousands of structurally deficient rural bridges that plague financially strapped counties across the U.S.

Why FRP?

150,000 US Bridges are Structurally Deficient or Obsolete

Many Bridges can be RESTORED rather than REPLACED

Composite Bridge Deck Technology

• Proven Technology (100+ Pilot Projects Complete)
• Restoration vs High Cost Replacement
• Lower Life Cycle Cost for New Bridges
• Installation in Days, Better Survivability
• Costs have Limited the Market Penetration

New Low Cost High Performance Composites

• SBIR Technology “Bridges” the Price and Performance Gap
• Co-Cure Allows Technology to apply to New Construction

“The full scale, prototype FRP deck panels performed exceptionally during all phases of testing. In general, results of the study indicated that the panels significantly exceeded the code required design forces in all instances. In flexure, shear and bearing, the average failure load exceeded the AASHTO Design Truck factored wheel load by nearly three times. Even more importantly, the panels behaved linearly-elastically throughout the full range of loading and possessed significant post-buckling strength. ” – MISSOURI DOT (JUNE, 2017)

About This Project

The University of Tennessee and the Institute for Advanced Composites Manufacturing Innovation (IACMI) has partnered with Morgan County, TN and Morgan County Highway Superintendent Joe Miller to create an affordable bridge that can be installed quickly and will safely meet transportation needs

Morgan County will now be home to a low-cost, low-maintenance, technologically advanced composites bridge deck system with a 100-year lifespan

Located one-hour northwest of Knoxville on Elizabeth Church Road, Miller said the two-lane bridge has needed repair for many years, with rainstorms causing the road to flood to the point of being impassable

A team of researchers at the University of Tennessee’s Fibers and Composites Manufacturing Facility and Joint Institute for Advance Materials is working with IACMI and the bridge project team to equip the new FRP bridge deck with high-density fiber optic sensors and a state-of-the-art wireless sensor module system to monitor the composite bridge deck system while in-service.

“Lack of durability data is one of the major barriers of the adoption of novel and advance materials including carbon, basalt, or glass fiber reinforced polymeric composites in civil infrastructure,” said Dayakar Penumadu, the Fred N. Peebles Professor in the Tickle College of Engineering at UT and Characterization Fellow for Materials and Processing for IACMI.

Optical Sensors:

Composed of high density optic fiber and fiber bragg grating sensors developed by Luna Inc. A single 10-meter sensor can provide strain from mechanical loading or thermal/hygroscopic loading from thousands of locations simultaneously with exceptional precision. These are easy to install while composite decks are manufactured and become part of the structural component. Because of its expense and susceptibility to theft or damage, the optical system interface is not employed continuously but is easily attached and activated on demand.

“This is a major obstacle for integrating new materials and structures quickly and thus require successful demonstration as being done through this IACMI project. Bridge decks are the most damage prone elements, and we are integrating smart sensors distributed throughout the composite bridge deck that will provide us valuable performance data with time for years to come.” Professor Penumadu

Wireless Sensors:

Wireless technology developed at the University of Tennessee is being utilized to continuously monitor the response of the bridge system. Because of its low cost and protected position embedded in the bridge structure, the wireless sensing system can be continuously active. A narrowband LTE wireless interface transports the data to a cloud database system where it is archived for subsequent analysis by human and automated tools to rapidly identify variation from nominal conditions. Any variations would then trigger a more detailed analysis by the fiber system.

Lack of durability data is one of the major barriers of the adoption of novel and advance materials including carbon, basalt, or glass fiber reinforced polymeric composites in civil infrastructure. This is a major obstacle for integrating new materials and structures quickly and thus require successful demonstration as being done through this IACMI project. Bridge decks are the most damage prone elements. The optical and electronic instrumentation created by this project team will provide valuable performance data in real time for years to come.

Wireless Sensing System Specifics…

The Wireless Sensing System utilizes an array of electronic and electro-mechanical sensors with individual wireless controllers inunique configurations enabled by the composite construction of the bridge deck.

Data Collection

Example Displacement Data with Time for Extreme Loading Conditions

hover over any object for more information

Temperature

Multiple digital temperature sensors are embedded directly in the composite upper and lower surfaces to track thermal cycles and uneven thermal stresses on the bridge deck

Accelerometer & Magnetometer

Multiple 3 Axis magnetometers & accelerometers are embedded in voids in structure under the deck. The magnetometers cooperate to avoid false triggers while counting vehicles directly through the composite deck. The accelerometers search for threshold events and provide 20mS resolution envelope profiles to the archive for analysis.

Accelerometer & Magnetometer

Multiple 3 Axis magnetometers & accelerometers are embedded in voids in structure under the deck. The magnetometers cooperate to avoid false triggers while counting vehicles directly through the composite deck. The accelerometers search for threshold events and provide 20mS resolution envelope profiles to the archive for analysis.

Local Concentrator

The local concentrator creates and manages the wireless sensor network, relays data via traditional wireless or narrowband LTE in remote areas, and records data if no communications are present. The concentrator can also accept commands from the admin console or software running in the cloud interface.

Narrow Band Cellular Network

A custom Narrow Band LTE interface is incorporated in the concentrator. This interface accesses the new AT&T CAT-M1 wireless backbone to cost effectively transport data to the Amazon Cloud from remote or mobile locations where traditional cellular is unavailable.

Server

Multiple secure servers are run virtually in the Amazon cloud to accept and archive data from multiple field deployments and return commands to sensor networks on the bridge. The entire system may be distributed across multiple servers for load balancing and reliability.

Database

An sql compatible mongo database holds all data and configuration. Data is timestamped to the microsecond and open interfaces allow data analytics tools and AI engines to analyze data independent of the collection and conditioning software.

Web interface

A custom web interface for data analytics has been designed to let researches look search data, view it graphically, and extract it for further analysis. This interface also provides the ability to monitor and push commands to the bridge to change sampling parameters and check on overall health of the wireless sensor network

Camera

A custom camera solution monitors the bridge in real time and simultaneous records and timestamps motion events. This allows events in the database to have associated video to observe exactly what was occurring in the event of an anomaly. Or to look up data based on an observed video event. All clocks are synchronized for accurate retrieval

Deflection Ambient Temp & Humidity

A hall effect deflection sensor is positioned under the bridge deck to monitor absolute flex offset to sub millimeter levels during vehicle passage. Data is recorded at 20mS intervals to give a time domain profile. This sensor also incorporates local air temperature and humidity under the bridge

Strain Gauge

Multiple Strain Gauges are placed on metallic members to record offsets of the supporting members independent of the deck during load events

Optical Sensing

Fiber Optic Sensor utilizes proprietary sensing technology for continuous and on-demand sensing for detecting strains and damage locations along the bridge deck panels. As an examples bridge is routinely subjected to tension and compressive force in response to normal vehicular traffic. Fiber Optic sensors are able to detect loads from vehicular traffic to access the health of the bridge. Tension and compressive strains along the bridge deck with external loading are monitored with multiple continuous fiber optic senses and an examples result if shown below.

Ways fiber optic sensing shows what you've been missing

Small, lightweight, flexible

More data, more insight

Electrically passive and environmentally stable

Distributes

Multi-parameter

Future Viability of Composite Bridges

Technology ready for installation

Seeking funding for implementation

Invest in the next generation infrastructure

• Durability
• Factory jobs
• Rapid deployment
• Reduced onsite construction impact
• Life cycle cost benefits

For more than 20 years, FRP composites have been used in bridge applications, and they’ve met and exceeded all performance and safety standards set by the Association of State Highway and Transportation Officials. But, when it comes to composite bridge decking, many transportation departments across the country are unfamiliar with the technology. The transportation market sector has huge growth potential as per the recent survey of Lucintel and ACMA