Rehabilitating concrete along interstates is not at all glamourous. In fact, when it’s done successfully, that’s the point – to complete the work quickly, and ideally, with little notice by the traveling public. But these projects can also be very challenging, often requiring constant coordination, attention to detail, and a particular emphasis on safety. Therefore, when the Florida Department of Transportation (FDOT) District 2 contracted with RS&H to lead the construction engineering and inspection of eight miles of concrete rehab along I-95 in North Florida, our team got to work on several behind-the-scenes measures for saving time and money, enhancing safety, and improving the overall public perception of the project.
Innovative Traffic Control Measures
From the project’s onset in May 2011, RS&H was proactive in identifying traffic control solutions that not only improved safety but also reduced time and costs. The team developed an alternative traffic control plan (ATCP) that allowed for simultaneous work in both directions of I-95, reducing the duration of the project by approximately 500 days. The plan also incorporated more than $550,000 worth of safety features at no cost to the FDOT, including eliminating traffic shifts within lane closures, removing channelizing devices from between active travel lanes, and adding contrast pavement striping to improve daytime visibility and performance. This revised plan also placed more emphasis on completing the mainline slabs before working on the ramps, which allowed the team to finish the most heavily used sections of roadway faster.
The team also utilized new technology, including eight GoPro cameras attached to an inspection vehicle, to safely monitor the work zone. Documenting the effectiveness of a traffic control plan while ensuring the safety of the team can be challenging. However, with the use of the GoPro cameras, which were linked to GPS coordinates, RS&H efficiently identified deficiencies or risk areas from multiple perspectives, as well as documented and communicated them instantly for correction.
The team also regularly monitored the effectiveness of reflective pavement striping using “reflectometers.” Since temporary striping can fade quickly, causing confusion for motorists, monitoring the reflectiveness and replacing when needed, reduced risk to both the contractor and the FDOT while improving lane visibility to the public.
Despite the number of safety improvements implemented, working along the interstate is still risky. On one occasion during nighttime operations, the driver of a small Honda was clipped by a semi-truck merging at the last minute where RS&H and the contractor were working. The car spun backwards and came to a rest in the middle of the interstate. Members of the contractor’s team responded immediately, pushing the vehicle into a lane closure to avoid any further collisions. The team was recently recognized with a Florida Transportations Builders Association (FTBA) Safety Award for their efforts.
Cost-Saving & Quality Improvements
In addition to traffic control and monitoring measures that focused on enhancing safety, we also implemented several changes to improve the overall quality of the project, including what the public notices most – ride quality. The original design called for grinding the final surface in one swoop at the end of the project, which isn’t expected to be completed until the spring of 2015. Instead, RS&H recommended phasing the grinding process, which provided finished sections years ahead of schedule at no added cost. The end result – a much smoother ride for motorists as each section was completed.
The original plans also placed the replacement of damaged slabs along the mainline, ramps and shoulders at the same priority, which would have left marginal slabs within the mainline. RS&H redesigned the work with emphasis on the mainline slabs as top priority since a cracked mainline slab will likely need to be replaced, whereas a shoulder slab can still perform for many years. The redesign minimized the overruns while maintaining a very high level of quality.
The team also worked very hard to defend the client from claims. At one time, the FDOT faced five claims by the contractor. Due to RS&H’s thorough documentation, negotiations, and open communication among all stakeholders, the contractor rescinded the claims. Other team successes included identifying and resolving issues with the contractor’s application of epoxy to help connect and secure the slab sections, which saved FDOT potentially more than $1 million in future repairs. Additionally, the team developed a solution for preserving an existing guardrail, which was originally planned for removal to allow for the assembly of sign structures. By keeping the guardrail in place, the FDOT saved more than $100,000, as well as both time and resources.
At completion in the spring of 2015, the project will have replaced more than 102,000 square yards of concrete pavement (10,250 slabs). The 8.25-mile project is expected to finish ahead of schedule and will be the only major concrete rehab project in District 2 completed without any contractor claims. The success is a testament to the team’s meticulous inspection, documentation, and engineering improvements.
— By Ryan Poulsen, PE