FORTA Corporation


Lanai Breakwater Core-Loc Dolos


Lanai, Hawaii

The relatively small island of Lanai, Hawaii, depends heavily on the Kaumalapau Harbor for tugboat and barge deliveries for all commercial goods. The Kaumalapau Harbor needed 800 Core-Loc dolos to protect its breakwaters and shore. The durable concrete used in Core-Loc dolos creates a strong, interlocking unit with high stability and relatively low cost. However, the significant heat of hydration produced during mass concrete placement of the Core-Loc dolos presented a challenge.

To help eliminate cracking, the approach included applying several inches of insulating foam to the steel form exterior prior to concrete placement, the use of a 60/40 ratio of chilled water to ice, and the inclusion of FORTA-FERRO macrosynthetic reinforcing fibers at a dosage rate of 5 lbs/yd3. In total, the project required 70,000 pounds of FORTA-FERRO to reinforce 14,000 cubic yards of concrete. It has been honored with several national and regional project awards for its remarkable innovation and solutions to challenging construction issues.