Protecting concrete usually means shielding it from the elements of nature or from harsh manmade chemicals. But it’s not just concrete that needs such protection. Corrugated metal pipe, steel surfaces, material hoppers, rail cars and masonry all can come in contact with corrosive or abrasive materials or harsh conditions.
The geotechnical needs of DOTs and other agencies responsible for roads and bridges are vast. Issues include: Culvert repair Soil stabilization Void filling Concrete slab lifting Sinkhole remediation Slope control Slough control in tunneling
General Contractor: West Coast Construction
PROBLEM: West Coast Construction subcontracted to a local contractor for seawall repair at Lake Park Marina in Lake Park, Fla. Voids had developed beneath the sidewalks and under the toe of the seawall, plus many of the joints were leaking.
SOLUTION: West Coast removed the sidewalks and pavers adjacent to the seawall. The consulting engineer identified the exact locations for repairs. The contractor injected Prime Flex 920 through ½” probes approximately 12’ deep to fill the voids and seal the joints. Prime Flex 920 is a super low viscosity hydrophobic polyurethane resin that reacts with water to form a rigid, watertight mass. Its low viscosity, water-reactivity and the fact that it meets NSF/ANSI Standard 61 for contact with potable water, make it a good choice for seawall repair. The work was done in five or six phases so that the entire marina wasn’t torn up at one time. West Coast would prepare a section, then the contractor would grout that section with about a week between each phase.
CHALLENGES: “The job was fairly standard,” said the contractor, “but one challenge was that some of the boats in the marina were docked very close to the location we were working.” The crew had to be especially vigilant about avoiding overspray that could contact the boats. They also established floating barriers in the water to contain grout that flowed through the seawall in the process of sealing the leaks. These barriers ensured that the reacted grout could easily be contained, removed and disposed of.
Each section of wall required 100-120 gallons of 920 to complete repairs, so 500-600 gallons were used in total for the project by a four-man crew.
OUTCOME: The grouting was successful and without complications.
“Everything went really well,” said the contractor. “The material worked well. It was a nice, straight forward job that was actually pretty easy, which is always great.”