The California Department of Transportation District 7 will begin the first of two weekend repairs on the Santa Ana Freeway (Interstate 5) bridge over the Rio Hondo River on Oct. 17 following damage from a fire that started in a homeless camp under the bridge this past July.

Caltrans will use an innovative, rapid-set concrete mix to reduce the curing time to six hours instead of 36 hours, allowing the road to be closed for a shorter period.

All southbound lanes and one northbound lane will be repaired on the bridge. Work will be phased over two weekends in order to minimize impact to traffic. Two southbound lanes will be repaired the first weekend with the remaining two southbound lanes and one northbound lane repaired during the following weekend, October 24, weather permitting.

“Using this approach allows us to open the freeway in two days while also keeping two lanes open during construction,” said Caltrans District 7 Director Carrie Bowen. “It is important to finish the repairs to the bridge prior to the rainy season and for our community and businesses to have the work completed before the holiday shopping begins.”

Southbound I-5 will be closed each weekend between Slauson Avenue and Paramount Boulevard from 2 a.m. to 6 a.m. on Saturdays to re-stripe the freeway and place temporary K-rail in preparation for deck removal in two lanes. Only two of four lanes will be open during the day as crews tear out damaged concrete. During the second weekend, a northbound lane will also be closed during the day while the deck and median barrier are demolished.

At 11 p.m. each Saturday night during these weekend closures, the entire I-5 freeway will be closed between Slauson Avenue and Paramount Boulevard along with connector closures from I-605 while concrete is poured and cured. The first weekend, northbound I-5 will re-open at 5 a.m. and southbound I-5 will re-open at 9 a.m. The second weekend, northbound I-5 will re-open at 7 a.m. and southbound I-5 will re-open at 10 a.m.

On both weekends, motorists can expect nearly two hours of travel time on southbound I-5 with backup as much as three miles. Travel time on northbound I-5 through the area is anticipated to be 30 minutes with a one-mile backup.

Motorists should plan ahead and use public transit when possible. Alternate routes are strongly recommended to reduce traffic in the area. Businesses will remain open.

This unique concrete mixture hardens quickly but cannot experience any vibrations or it may crack requiring crews to rip it out and start over, so the freeway must be completely closed.

The deck over the Rio Hondo River was damaged beyond repair and is slowly crumbling. Additionally, the deck has surpassed its 50-year service life, so patching it is not an option.

Full and partial freeway, ramp and connector closures can be found on http://dot.ca.gov/dist07/rio-hondo.

The emergency contractor on these repairs is Flatiron Construction, Inc. of San Marcos, Calif.