Converting more than 256,000 barrels of crude oil per day, one of the largest refineries in the United States needed to bring a 9,600-square-foot dock into compliance with environmental regulations. It is critical that any accidental spills are contained on the dock and do not make their way into the nearby Mississippi River. To comply with environmental regulations, the dock needed to act as a secondary containment structure. The dock had no coating to contain spills, so the owner decided to hire a specialty contractor to install a protective coating.

Having worked with this owner since 2001, Structural Preservation Systems (SPS) was brought onto the project to bring the dock into full containment. The dock had been in operation for more than 30 years, so decades of dirt, grime and oil had settled onto the dock's surface. In addition, heavy machinery used on the dock had damaged the surface. Ten months before the start of the project, SPS conducted a pilot test on two different coatings to see which one would perform best. After months of testing, it was clear that the polyurea coating was the best solution.

SPS recognized from the onset that the key to success on this project would be the surface preparation for the coating. Since the concrete surface was contaminated by oils and gas, a degreasing agent was put on the concrete. The damaged portions of concrete were removed via pneumatic chipping hammers and failed joint material was removed in its entirety. All cracks were routed out using crack chasing "V-blades'" and an elastomeric polysulfide joint filler was installed. Crews saw cut the perimeter of broken or damaged concrete in a rectilinear configuration a minimum of ½-inch to prevent featheredging of the new repair material. Crews also had to resurface large sections of the concrete because of the extensive damage. Both sandblasting and shotblasting equipment were used to remove all embedded contaminants and to prepare the concrete for the new coating. Concrete needs to have an aggressive profile to enhance the mechanical bond of the new material to the existing concrete. To verify that all the contaminants were gone and the surface preparation was sufficient, the crew performed direct tension pull-off tests. The team also confirmed that the concrete did not contain excess moisture, which would impact the coating's performance, by performing calcium chloride tests. A complex maze of pumps and pipes location on the dock made the surface preparation additionally challenging. SPS used shrink-wrap to cover the piping before the spray-applied coating was installed.

Crews installed a penetrating primer to the concrete to seal the pores of the concrete from potential moisture vapors coming from the river in the future. The team installed coves at all horizontal and vertical interfaces to prevent coating failure and cracks at these locations. Utilizing specialized equipment, crews then installed the polyurea coating, which cures to the touch in seven seconds. Because there are concerns with concrete outgassing, the team installed the coating system in the evening when the ambient temperature was dropping. Pin holes would have developed if the coating was applied during the day because of the concrete outgasing.

Schedule was a primary concern on this project. SPS performed the work during a planned short duration outage and had to coordinate with several other contractors who were working on the dock during the project. SPS completed the project 1.5 weeks ahead of schedule and the owner was extremely satisfied  with the result. They were impressed that the extremely high quality of work could be performed during such a short time.