On Monday, Southern Arizona experienced its wettest day in recorded history. Remnants from Hurricane Norbert mixed with pre-existing monsoon humidity to cause over 3.25 total inches of rainfall in a single day. Typically, the region sees 2.71 inches of rain for the entire monsoon season. However, on Monday alone, 2.96 inches had already fallen by 8:30 am, and the downpour didn't let up throughout the day. Tragically, two people lost their lives while attempting to escape the rushing waters, and more than 10,000 homes and businesses were left without power. Entire sections of interstates in Phoenix were washed away, while here in Tucson, high waters in the Santa Cruz River have threatened the structural integrity of all bridges along that river. The damage from Monday's flood continues to mount as saturated soils create instability all around us. As the damage climbs, so does the repair bill. In addition to the countless homes and businesses needing restoration, bridges and entire road sections will require rebuilding. Regrettably, this isn't the first time that floods have caused extensive damage to our transportation infrastructure, and it won't be the last.
In 1927, a flood in Vermont resulted in 84 fatalities, left another 9,000 people homeless, and destroyed 1,250 bridges. An 1891 flood in Arizona caused a railroad bridge across the Salt River to collapse, leading to shortages during the 3-month repair process. A 20-day flood in Oregon and Northern California in 1964 claimed 19 lives and destroyed over 20 major highway and county bridges, resulting in hundreds of millions of dollars in damages. While many of these disasters occur without warning, preemptive efforts can help prevent such extensive damage to our infrastructure.
One DOT (Department of Transportation) recently decided to use carbon fiber to preemptively strengthen one of their highway bridges. Tiny cracks had developed as a result of vibrations from daily traffic passing overhead. Over time, water and oxygen had seeped into the cracks, causing them to expand and corrode the concrete and reinforcing steel rebar within. The bridge had more than 60 corroded concrete columns; the columns were so corroded that whole sections of concrete had fallen off, exposing corroded rebar throughout. Recognizing the imminent risk of a bridge collapse, the DOT opted to repair the bridge with HJ3's carbon fiber solution. Before installing the HJ3 Civil™ system on the bridge columns, all the damaged concrete was removed with chipping hammers. The exposed rebar was cleaned to near-white and protected. Wooden forms were constructed around the columns to encase a high-strength grout that was poured in place. Finally, the resurfaced columns were primed, wrapped with HJ3's carbon fiber fabric, and layered with a protective topcoat.
The HJ3 Civil™ system successfully restored the columns' shear and tensile capacities in only three weeks. The DOT saved 50% of the replacement costs, and the entire repair was completed with minimal road closures. Thanks to HJ3's system, the bridge is now corrosion-resistant, eliminating the need for future maintenance. Additionally, repairing the bridge rather than replacing it saved months of downtime and prevented more than a million gallons of water from being wasted in the construction of new columns.
If you have a bridge that requires strengthening, please let us know! Shoot us an email at Info@hj3.com.
