Heavy Equipment Guide Logo

Ground penetrating radar provides critical insight for maintaining Canada's aging roads and bridges

GPR data is captured at posted speeds, often eliminating the need for traffic disruption or road closures.
GPR data is captured at posted speeds, often eliminating the need for traffic disruption or road closures.

Company info

325 Matheson Blvd E
Mississauga, ON
CA, L4Z 1X8


Read more

Municipalities across Canada are burdened with aging transportation infrastructure, much of which was constructed in the post-war era and is nearing the end of its useful life. The 2016 Canadian Infrastructure Report Card (CIRC) found that one third of municipal infrastructure across the country is in fair, poor or very poor condition, and this includes 39 percent of roads and 26 percent of bridges. Cold weather and the use of corrosive de-icing salts further threaten the reliability of the transportation infrastructure we rely on every day.

The estimated replacement value of these roads and bridges is upwards of $380 billion, and municipalities are responsible for covering 60 percent of their own costs. As such, finding cost-effective, efficient condition assessment tools and techniques has become vitally important. Municipalities are now looking beyond traditional methods to assess road and bridge conditions and strategically prioritize maintenance and rehabilitation activities.

Gaining insights with GPR
From 2006 to 2015, the second Strategic Highway Research Program (SHRP2) was launched south of the border as a mechanism to find strategic solutions to three national transportation challenges: highway safety, congestion, and bridge and road renewal. The report concluded that non-destructive condition assessment significantly reduces the overall resources and expenditures required for bridge and road renewal. It also concluded that capturing data via non-destructive methods helps to prevent premature, unexpected failure.

Ground Penetrating Radar (GPR) ranked highest in overall value for assessing bridge deck deterioration based on accuracy, precision, speed, ease of use and cost. GPR is a technology that transmits high frequency radio waves into the ground or structure and analyzes the reflected velocity and energy to create a profile of the subsurface features. The reflections are caused by a contrast in the electrical properties of subsurface materials which can be indicative of changes in water content, void spaces in the ground or structure, rebar or post tension cable corrosion, asphalt deterioration and other factors.

By revealing the complex substructure of a road or bridge, GPR can detect anomalies between coring locations, and allow project stakeholders to achieve a continuous profile of subsurface conditions. As an added benefit, fewer core samples are required because they can be strategically placed based on the GPR results - for example, in areas where the road or bridge appears to be in the worst condition. Dan Conte, Senior Bridge Engineer for URS Canada (an AECOM company) explains:

"GPR evaluation provides an additional dataset that can be cross-compared and correlated with results from traditional condition survey techniques. This makes it possible to readily identify locations of suspected deterioration and therefore target areas where destructive or intrusive sampling should be carried out during follow-up condition surveys." 

Once a GPR survey is complete, reports illustrating the internal condition of a road or structure can be generated in many formats, including plan maps, colour contour maps and 3D. This information can then be integrated into a GIS or CADD-based system for reference years down the line, so that patterns of deterioration can be evaluated over time. 

Rehabilitating roads in our nation's capital
GPR has been applied on multiple highways and roads across the City of Ottawa and surrounding area, including Highway 417 which connects Montreal with Ottawa and is considered the backbone of the transportation system in the National Capital Region. The technology has been applied to assess road structure, pavement, concrete and asphalt thickness in order to inform strategic decision-making around improved driving surfaces, localized repairs, and accessibility improvements and updates.
GPR surveys were carried out using a ground-coupled, high-speed system that allows for surveying up to 1.5 metres in depth and incorporates real-time GPS synchronization. Survey profiles and reference stations for the data acquisition were established according to the customer's base maps and project requirements. Data was collected at posted travel speeds, eliminating the need for traffic disruption or road closures. 

Data collected in the field was digitally recorded and backed up on site. The data was then processed and analyzed to determine the average thickness of pavement, concrete and asphalt subgrade layers. Results were presented in scaled and referenced colour contour maps along with plan and sectional views of the road and bridge structures. Statistic summary tables were also provided that depicted average, maximum and minimum estimated thicknesses. 

Preserving Toronto's main artery
The City of Toronto's Gardiner Expressway serves as the main artery into the City, stretching 18 kilometres from the Don Valley Parkway to the Queen Elizabeth Way (QEW). In operation since 1955, structural concerns have required sections of the Highway to be rehabilitated and, in some cases, replaced.

To get an accurate picture of the Expressway's condition, GPR was used to map bridge deck deterioration over a vast, geometrically complex area. All continuous east and westbound lanes of a 6.1 km raised section were analyzed, along with access ramps. High-resolution GPR observations were collected during an overnight survey from curb to curb, less than a metre apart at a speed of 60 kph, so traffic flow was only minimally disrupted. Six lines of data were captured for each vehicle lane and over 1.3 million targets within the project area were processed and georeferenced to assess deterioration. 

Data was then digitally recorded to produce colour-coded contour maps for each section of the highway. A bridge deck deterioration index was also developed that indicated the percentages of each section appearing to be above the deterioration threshold. To ensure accuracy, data was correlated with known structure information, including existing coring data. Dr. Peter Annan, P.Eng, Ph.D, Founder of Sensors & Software, explains: 

"Non-destructive technology has the unique ability to detect deterioration and other subsurface anomalies before they develop into serious concerns. Techniques such as GPR reveal changes in subsurface properties that allow suspicious areas to be targeted for further evaluation and preventative remediation. Many traditional methods of inspection will detect deterioration only once the concrete or bridge deck has already become cracked or delaminated."

Ground Penetrating Radar (GPR) reveals changes in subsurface properties between widely spaced core samples so that a continuous profile can be achieved.

Maintaining safer bridges
As part of a coordinated bridge maintenance and rehabilitation program, GPR was applied to assess the condition of various bridges connected to the Queen Elizabeth Way (QEW) highway from Mississauga to St. Catherine's, a stretch of approximately 90 kilometres. The objective of the survey was to determine the condition of concrete decks, pinpoint areas of potential deterioration and delamination, and confirm the thickness of concrete slabs below the asphalt surface.

The client was provided with a digital geophysical interpretation report that included plan maps, cross sections and mapping profile images of the subsurface layers, and corresponding thicknesses. The report also included recommendations for follow-up testing based on areas that demonstrated deterioration and delamination. The information provided was used to support strategic decision-making around the prioritization of maintenance and rehabilitation activities. 

Looking ahead
Over the next several decades, much of our municipal transportation infrastructure will be in need of costly repair and rehabilitation. Adding Ground Penetrating Radar (GPR) to the infrastructure inspection process can improve reliability and assist municipalities in planning strategically. As road and bridge defects are often not visible, particularly when a surface has been repaved, GPR has the ability to detect areas that are unusually thin or thick and identify subsurface defects below asphalt overlaid roads and structures. This is accomplished non-intrusively so that structural integrity remains intact. Furthermore, with the cost of traffic congestion estimated to be upwards of $6 billion annually for Canada's largest metropolitan areas, GPR offers the added advantage of capturing data at posted speed limits, often eliminating the need for road closures and traffic control.

Kevin Vine is president of multiVIEW Locates Inc. 

Benefits of GPR

Ground Penetrating Radar (GPR) transmits high frequency radio waves into a ground or structure and analyzes the reflected velocity and energy to create a profile of the subsurface features. These subsurface features can include reinforcement bar or post tension cables, changes in water content, void spaces, rebar or post tension cable corrosion, asphalt deterioration and other factors. Benefits of GPR for bridge and road infrastructure assessment include: 
•  Achieve a continuous profile of subsurface conditions while minimizing the need for intrusive testing: GPR detects anomalies that exist between widely spaced core samples. Fewer cores are required because data collected by GPR fills in information gaps and provides new insights into subsurface conditions. Cores that are applied can be strategically targeted based on the GPR results, rather than randomly placed.
•  Detect subsurface threats before serious issues develop: Defects and wearing reduce structural capacity over time and can lead to an eventual failure. These defects are often not visible, particularly when a surface has been repaved. GPR has the ability to detect areas that are unusually thick or thin and identify subsurface defects below asphalt overlaid roads and structures. 
•  Obtain a rich source of data that can be leveraged years down the line: GPR data can be combined with countless other datasets to provide a complete picture of subsurface conditions. Project stakeholders can visualize deterioration and rebar corrosion along with the position of post tension cables and other subsurface features. This supports a better understanding of lifecycle costs throughout the aging process. The GPR data can also be saved and referenced years down the line when the infrastructure is re-inspected.
•  Minimize and eliminate service disruptions: With the cost of traffic congestion estimated at more than $6 billion per year across Canada's major metropolitan areas, GPR offers an advantage in that data can be captured at posted speed limits, often eliminating the need for road closures and traffic control.

More from Roadbuilding

Contractors hit compaction quality targets with Cat COMMAND

Caterpillar has announced the release of Cat COMMAND for Compaction, an operator-assisted technology that automates the soil compaction process and helps contractors achieve compaction quality. The COMMAND for Compaction system is available for use on select Cat vibratory soil compactors as a dealer installed kit on both new and existing B-Series machines.

New generation of pneumatic tire rollers

The HP series of pneumatic tire rollers is packed with technical innovations and further developments. Hamm has developed a common platform as the basis for all model variants in every market throughout the world. In addition, there are important innovations affecting the operator's platform, the water and additive sprinkling system as well as the ballasting.

Neal Manufacturing's High-Volume Road Maintenance Vehicle boasts efficient, clog-free movement of material

Neal Manufacturing, a division of Blastcrete Equipment LLC and a manufacturer of asphalt pavement preservation equipment, offers its High-Volume Road Maintenance Vehicle for maximum efficiency and high-quality results on large road projects. With innovative features and in-cab controls for key variables, the High-Volume Road Maintenance Vehicle allows for fast, precise sealcoat application, even with larger aggregate mixes.

Bomag adds 10-foot highway-class paver with new features, improved operator experience

BOMAG 10-ft (3.0-m) pavers now include significant upgrades to the operator's platform, which improve visibility and the operator experience. New dual swing-out operator stations feature BOMAG's SIDEVIEW innovation in which the seat and console swivel outward at four differing angles to deliver unobstructed views to the sides of the paver and the screed end gates. An open-grate design on the platform floor affords the operator direct-line sight of the screed spreading augers.

How technology is boosting cold milling productivity

Asphalt milling, asphalt grinding and asphalt planing describe the same process by which weathered, oxidized asphalt pavement is removed from a driving surface in varying depths, as specified, done in advance of a fresh asphalt overlay or pavement preservation treatment. 

Bergkamp Pivot Tack System for FP5 Flameless Pothole Patcher eliminates tripping hazards and keeps tack off of equipment

Tack that is sprayed into potholes to increase adhesion within a patch can also adhere to equipment hoses. In addition, the hoses can present jobsite tripping hazards. To address these common issues, Bergkamp Inc. has engineered a new Pivot Tack/Air Hose System for its FP5 Flameless All-In-One Pothole Patcher. Located at the back-right side of the FP5's hopper body, the system's pivoting arm holds the original tack hose off of the ground and parallel to the hopper, locked in place for transporting with a spring-loaded pin. 

Subscribe to our free newsletter

Get our newsletter

Learn more

Recycled aggregates for roads

Municipalities are responsible for the care and maintenance of vast amounts of roads, from lanes to highways. When those roads are repaired or replaced, there's the potential to generate a significant amount of aggregate material - concrete and asphalt removed from the surface that must be dealt with.
Today's roadbuilding contractors are taking this material and recycling it more than ever before. However, research is showing that some municipalities are far better than others when it comes to using this type of aggregate in their roads - and some are far behind.

Case adds two new vibratory rollers to DV Series

Case Construction Equipment has introduced the latest additions to the DV Series of vibratory rollers. With models available in both double drum and combination (front drum with rear pneumatic tires) configurations, these rollers are powerful, easy to transport and nimble enough to work in a variety of residential and commercial construction applications where the operator may encounter tight quarters, curbs, structures and other obstacles.

State-of-the-art high-performance W380 CRi cold recycler from Wirtgen

Due to the rapid increase in heavy-duty transport, the global road network is showing visible signs of aging in many places. In order to ensure that the road infrastructure remains functional over the long term, roads are increasingly requiring structural rehabilitation. Wirtgen developed the high-performance W 380 CRi cold recycler specifically to meet these requirements. This innovative machine will be unveiled to the world at the Bauma trade show. 

Wacker Neuson restyles ride-on roller for improved visibility and curb clearance

Wacker Neuson has updated its 1.2-ton tandem vibratory roller line to include improved visibility, curb clearance and easier service access. The RD12 series has dominated the industry since it was originally developed and introduced to the North American market 30 years ago. These popular ride-on rollers are the perfect fit for residential and commercial construction for asphalt and subbase soil compaction of parking lots, driveways, secondary roads and nature trails. Additionally, they are an excellent choice for landscape and golf course contractors to statically roll sod, fairways and greens.

Efficient fleet management with WITOS FleetView from Wirtgen Group

"A penny saved is a penny earned." WITOS FleetView is a must-have for anyone who takes this old proverb to heart, because with the fleet and service management solution from the WIRTGEN GROUP, users and machine operators have diverse advantages that are worth their weight in gold. An example from the field confirms it: GSI-Asphalt, a medium-sized enterprise in Eging am See, near Passau, Germany, has been using WITOS FleetView for years in conjunction with the SmartService service agreement. While SmartService provides for regular inspections in accordance with the instruction manual, the telematics solution WITOS FleetView additionally supports proactive maintenance planning and a rapid response in the event of faults. Both services guarantee maximum machine availability - enhancing the cost-efficiency and value retention of the machinery.

Subscribe to our free magazine

Get Our Magazine

Paper or Digital delivered monthly to you

Subscribe or Renew Learn more

World premiere of Bell Equipment's B45E 4x4

With the launch of the new Bell B45E 4x4 at bauma, Bell Equipment will add a new model to its range of articulated 4x4 two-axle ADTs. Similar to the sixty-tonner B60E and the smaller Bell B30E 4x4, the new truck is configured to provide a highly efficient and cost-effective transport solution for niche applications in the mining and construction industry.

New Dynapac pavers take commercial class to the next level

Dynapac North America upgrades its commercial class paver range with the new FC1700C, FC1400 II, and FC1300 II.  The new pavers are equipped with EPA Tier 4 Final certified emissions regulations-compliant engines and offer new features that takes the Dynapac commercial class paver range to the next level.  The launch of the new FC1700 will take place at the National Pavement Expo in Nashville, TN.  

Bomag BF300 commercial pavers bring unique features to improve quality and efficiency

BOMAG introduces the new BF 300 series of commercial pavers that offers big paver features and efficiency in a 6-ft (1.8-m) paver. The rubber tire BF 300 P-2and BF 300 C-2 track pavers are designed to elevate paving quality and productivity, while reducing costs on a range of municipal, department of transportation, city development, and bike and cart path applications. 

Volvo CE expands ActiveCare Direct to pavers

Originally launched in 2017 for excavators, articulated haulers and wheel loaders, ActiveCare Direct is now available on select Volvo asphalt pavers. Starting February 2019, the P7110B and P7170B will be eligible for a one-year free subscription to ActiveCare Direct with a new machine purchase.

Bridgestone brings portfolio of OTR tire solutions to AGG1

Bridgestone Americas, Inc. will exhibit its integrated portfolio of off-the-road (OTR) products, technologies and services at the National Stone, Sand and Gravel Association Aggregates Academy and Expo (AGG1) and World of Asphalt 2019 Show and Conference, Feb. 12-14 in Indianapolis, Indiana. Located at booth 31089, Bridgestone will showcase the benefits of using products backed by integrated technologies to drive increased productivity for customers.

Subscribe to our free newsletter

Get our newsletter

Learn more

CASE launches new series of small-frame vibratory rollers

Case Construction Equipment has announced a new series of small-frame vibratory rollers. Available in both double drum and combination (front drum with rear pneumatic tires) configurations, these compact rollers are easy to transport and are ideal for working in residential and commercial construction applications where the operator may encounter tight quarters, curbs, structures and other obstacles.

Komatsu America and Bomag distribution partnership paves way to new market opportunities

Bomag Americas, Inc. and Komatsu America Corp. are pleased to announce that Komatsu's six company owned dealerships (Edward Ehrbar, Komatsu Equipment Company, Komatsu Northeast, Komatsu Southwest, Midlantic Machinery and Pine Bush Equipment) have entered into an arrangement for the sale and support of Bomag compaction, milling, paving and reclaiming/stabilizing equipment for roadbuilding and other construction markets. 

Bomag's new paving training programs help operators and companies get the most from their equipment

For asphalt contractors to be successful in today's competitive paving market, paver and roller operators must acquire a deep knowledge of the equipment's features and put this knowledge into practice at the jobsite. With long-time equipment operators retiring at a high rate, the next generation of operators must receive extensive in-depth training on the equipment in order to meet project specifications without costly rework so companies can maximize equipment return on investment.

Asphalt Drum Mixers offers crane-set and self-erect asphalt storage silos

Asphalt Drum Mixers, Inc. offers crane-set and self-erect asphalt storage silos, which are compatible with both the company's own and similar competitive models of asphalt plants. ADM silos are available in many configurations from single self-erecting silo to multiple crane-set silos and several drive-through configurations. Capacities are available between 30 and 300 tons. Custom designs and capacities are also available to accommodate any producer.

Road Dryer RD-1200 safely dries pavement in one pass for paving, surface treatments

The RD-1200XT pavement-drying unit from Greenville, South Carolina-based Road Dryer, LLC, quickly dries asphalt and concrete pavement, allowing crews to pave or apply surface treatments or striping after just one pass. The unit, which blows heated air up to 300° F directly downward through multiple nozzles, eliminates the risk of "flying objects," and allows traffic to flow in nearby lanes — reducing congestion caused by traffic restrictions. Available as a simple-to-operate trailer- or truck-mounted unit, the RD-1200XT can be adjusted for 8-ft to 12-ft (2.4m to 3.7m) drying widths. Because it dries pavement on demand, it provides flexibility for contractors and government agencies to meet timetables by minimizing delays from weather- and project-related wet conditions.

Move big snow with Torwel's heavy-duty snow pushers

Torwel Limited has announced its new and improved Heavy-Duty Snow Pushers in widths from 8' through 18'. All models boast robust design and upgrades that include adjustable skid/wear shoes and easy to use attachment systems that include the universal skid steer mounting system and the new versatile utility tractor/loader global mounting system.

In-depth report: asphalt pavers

Trends in asphalt paving centre around making it easier and faster to lay down the highest quality pavement. In our latest in-depth report, our panel of experts from five manufacturers take a look at advances and technologies that are available in asphalt pavers, their current level of adoption, the advantages they offer, plus considerations when looking at the purchase of a new machine. 

Vögele offers new app for paver operators

JOSEPH VÖGELE AG are further extending their range of service and training options for users: using a specially developed app and the associated web special, job-site professionals can now get to grips with the ErgoPlus 3 operating concept quickly and easily with the aid of numerous animations. 

Subscribe to our free magazine

Get Our Magazine

Paper or Digital delivered monthly to you

Subscribe or Renew Learn more