Application Details

Due to their ever-active fault lines, many California buildings are undergoing seismic upgrades to prevent potential damage and injury from earthquakes. In fact, the Mandatory Soft Story Retrofit program, which was created in 2013 by the Department of Building, mandates that “all older, wood-framed, multi-family buildings in San Francisco with a soft-story condition” be seismically upgraded.

Many buildings throughout California, especially those built from concrete, aren’t required to upgrade, but in several cases, building owners are having upgrades completed anyway. One such owner recently called upon HJ3 to complete its building’s seismic upgrade; HJ3’s Civil™ system was chosen to complete the upgrade because of its incredible strength. More than 3,900 square feet of HJ3’s carbon fiber, including 1,700 carbon fiber anchor dowels, were installed on several of the building’s concrete walls, successfully increasing the walls’ shear and flexural capacity.

 

 

 

Installation

 

 

Before the HJ3 Civil™ Seismic Upgrade system was installed, all walls were cleaned of dust and debris. Holes for the carbon fiber dowels were drilled at intervals of 2 square feet all along the walls to achieve a homogeneous distribution over the CFRP-wrapped region. After priming, HJ3’s carbon fiber fabric was saturated with resin and applied to the walls, followed by the carbon fiber dowels. A few inches of loose carbon fibers were left to smooth radially against the newly-strengthened walls before HJ3’s ultra-durable topcoat was applied.

 

 

 

 

 

 

 

 

Conclusion

 

 

The entire seismic upgrade was successfully completed within 7 days. Not only is the building earthquake-resistant, but the carbon fiber upgrade saved a significant amount of money, downtime, and environmental costs compared with steel upgrades. Furthermore, since carbon fiber weighs only four ounces per square foot, upgrading their building with the ultra-light fabric resulted in practically no added weight to the structure; had the client chosen a steel upgrade instead, it would have added a dangerous amount of weight to the already-heavy concrete building.

 

 

 

If you have a building that requires a seismic upgrade or retrofit, and would like additional information about HJ3’s carbon fiber systems, contact us today at info@hj3.com.