These high-tech construction techniques can help civil contractors do their work safely and in less time.
Earlier this month, the American Society of Civil Engineers designated 13 new projects as Infrastructure Gamechangers — groundbreaking projects and programs that represent the latest innovations in transportation, water and energy infrastructure. Located across the country, these projects make use of the latest practices, principles and technologies to build and maintain infrastructure such as roads, bridges and tunnels more efficiently and safely and for less cost.
Four of these Gamechangers involve construction techniques currently in use by departments of transportation that could change the way that civil contractors operate. They are:
The Indiana Department of Transportation is using a concrete sensor system developed by Purdue University researchers to better pinpoint how far along concrete is in the maturation process. By leaving the sensors within the concrete for an extended period, engineers can study the effectiveness of their work over time, as opposed to the conventional testing period of just 28 days. The system also communicates to INDOT when concrete needs to be replaced.
The team is tracking concrete strength development in real time through measurements of hydration, stiffness, compressive strength and other properties. So far, the researchers and INDOT engineers have embedded the sensors into three highways and the Purdue team also is working with the Federal Highway Administration on a nationwide pooled fund study to implement the technology in other states.
The researchers say the policies could save millions of dollars per year and cut down on traffic.
“Being able to track concrete strength over a longer period of time would help engineers to know if they’ve over- or under-designed roads and better determine when to replace the concrete,” said team leader Luna Lu, an associate professor in Purdue’s Lyles School of Civil Engineering, in a release.
Unmanned bridge inspections
Scour, the removal of sediment around bridge substructures by fast-moving water, is a leading cause of bridge failure, according to the Michigan Department of Transportation. The agency has identified more than 400 bridges on the state highway system and nearly 1,200 on local roads that are ”scour critical” and in need of close monitoring during high-water events.
Typical inspection for scour involves inspectors launching a boat and probing the channel bottom with metal rods, weighted tape measures or sonar devices. During high-flow events, this can be a dangerous task, according to MDOT, and this is where the unmanned surface vehicle can come in.
The department is employing an autonomous boat-like device, called an unmanned surface vehicle (USV) to inspect bridge footings beyond what is usually possible during human dives. The 4-foot-long USV, named EMILY, uses cameras and sonar technology to investigate conditions around a bridge before determining if a crew member needs to get in the water.
Recycled road pavement
California-based TechniSoil Industrial's Neo product is a recycled road substance created by blending recycled plastics with reclaimed asphalt pavement. The company mills the existing roadway and mixes a polymer-infused substance with the reclaimed pavement, and then immediately re-paves the recycled substance back onto the road.
Neo uses 150,000 plastic bottles per lane mile to create a 90% reduction in greenhouse gas emissions, a decrease of 84 truckloads per mile of hauling waste asphalt out and new asphalt in, and provides the opportunity for same-day returns to traffic. In addition, Neo roadways are expected to last three times longer than asphalt and are about five times as strong as traditional materials, according to ASCE.
Highway worker protection vehicle
North Dakota Department of Transportation’s Autonomous Impact Protection Vehicle is used to protect construction crews from other drivers on the road who may not be paying attention to the construction site or have lost control of their vehicle. In 2019, 261 work zone related crashes occurred on North Dakota highways, resulting in 64 injuries and two fatalities.
The autonomous vehicle will improve safety in work zones by removing the driver from the impact protection vehicle during normal operation, according to NDDOT.
The technology, developed by Kratos Defense in partnership with Royal Truck & Equipment, converted a current NDDOT truck into a self-driving vehicle. The autonomous vehicle is monitored and controlled by a human-operated lead vehicle and will automatically follow behind construction equipment without putting a driver in danger.