The switch to Mateenbar increases float lifespan considerably. “The American Concrete Institute developed an accelerated test method to determine deterioration of GFRP rebar,” says Renshaw. “This test indicated that we should expect a strength retention of around 96% after 100 years.” At 25% the weight of traditional rebar, Mateenbar also reduces shipping costs and eases installation.
The GFRP thru-rods and Mateenbar have been standard in Bellingham’s Unifloat concrete dock system in New Zealand for the past three years, including more than a dozen projects. Last year, Bellingham introduced the final GFRP reinforcement into its floating concrete dock system – the waler.
Traditionally built with treated timber, walers are mounted to the side of multiple concrete floats and fasten them together. Pultron manufactures the walers with a pultrusion process similar to thru-rod production. However, in addition to the ECR glass rovings and polyester resin, the waler has a continuous filament mat for transverse strength and a surface veil that provides a smooth finish and additional UV protection.
Measuring 12 meters long and weighing 330 pounds, the waler is the largest, heaviest profile that Pultron has made.
“This created some challenges. For example, the waler required so many rovings that we had to extend the roving bay, which feeds glass fibers into the pultrusion machines, making it both longer and taller to increase the capacity by 30%,” says Renshaw.
Pultron also had to modify its handling processes. While other products could easily be moved by one or two people after production, the waler required installation of a moveable gantry.
“When the factory was built over 35 years ago, the longest product that Pultron regularly made was much smaller,” says Renshaw. “Trying to maneuver a 12-meter-long waler weighing 150 kilograms around a factory that was never built for such large, heavy profiles is not easy.” Pultron is currently expanding its factory to increase capacity, improve efficiencies and allow for easier handling of such large sections.
The first installation of the GFRP-reinforced Unifloat concrete dock system added 100 new berths and a fuel jetty in Half Moon Bay Marina in Auckland. Bellingham will soon begin installation on the first Unifloat dock system in the United States to systematically refurbish and rearrange 2,400 traditionally reinforced berths in Dana Point Harbor, Calif., while the marina remains open. Sustainability was a selling point for the California marina.
“FRP walers are considered to preserve water quality and ensure no treated timber [chemicals] leaches into the water,” says Chris Lamont, general manager of Bellingham Marine New Zealand. “Dana Point has large sea lion populations, and this was very important to the project to ensure that they and other marine life were not compromised.”