November 8, 2018
The Contractor has wrapped up work for the winter as of today. The patch and repair, underground work, installation of electrodes/anodes, and carbon fiber wrap has been completed on the west side of the bridge. The Contractor has also completed the two rectifier pads on each side of the railroad tracks and the patch and repair, underground work on pier 10. Work is anticipated to start up again April 15, 2019 by finishing the patch and repair of pier 9. During the work in the spring there will be a period of time that traffic will be reduced to one lane in each direction while a crane is used to access pier 7 and 8 from the top of the bridge. We ask for your patience with the traffic controls as we work to complete this project.”
October 10, 2018
The contractor has begun testing the strength of the carbon fiber wrap. The first step is to use a hole saw to cut a 2” dia hold in the carbon fiber wrap. Then they bond a little metal piece to the carbon fiber wrap with epoxy. After it has dried for 24 hrs, they use a machine to fit over the metal piece and apply pressure to test how much the fiber can withstand before it lifts free. The requirement is to get at least 200 PSI. We are getting over 500 so far and the fiber is not failing, the grout is breaking instead. The carbon fiber is passing the tests with flying colors so far.
October 5, 2018
Mid-July through the beginning of September the contractor has been rehabilitating the west side of the bridge then moved to the east side mid-September. The shoring for pier 9 and 10 has been installed and the contractor has been working on concrete patch and repair on those piers. The cathodic protection installed so far has been tested and has passed. Next week the contractor will be working on the pier caps on 9 and 10 as well as testing the strength of the carbon fiber wrap. The work on this bridge will stop for the winter around the first of November. For the remainder of October they will be focused on finishing the rehabilitation process on piers 9 through 12.
July 19, 2018
The contractor has begun installing the carbon fiber wrap to the structure. The purpose of the carbon fiber wrap is to reinforce the tensile strength of the rebar. First they roll down epoxy primer (dark gray color), then a layer of epoxy filler (light gray colored, fills in pock marks in concrete to increase surface contact), then epoxy saturant (blue, this saturates the fiber wrap bonding it to the concrete), and finally they install the carbon fiber strips. Depending on the strength needed some areas have two layers of the carbon fiber wrap and some have 4 layers. There is an epoxy saturant coat between the carbon fiber wrap layers and on top of the last fiber wrap. These areas will be painted gray when the process is completed. The carbon fiber system has to cure for 3 days before they can take out the shoring and it will be 7 days before it is maximum strength.
July 13, 2018
The contractor is approximately half way through the patch and repair portion of the work on the structure. Crews have bored 2-inch diameter holes in the columns and caps and are placing rust-prevention anodes into the structure. The photos below show the process, first the holes are filled with grout and then the anode is pushed into the grouted hole. The anodes will be connected with wire to an electrode (shown with yellow cords) that is producing current (.85 and 1.2 volts DC). This will cause the anode to rust instead of the rebar in the structure. Once the project is complete, 518 anodes and 79 electrodes will be installed which will help extend the life of the bridge. The contractor is working on installing the anode system on piers 1-6 currently. Next week they will begin the carbon fiber wrap to further strengthen the columns and pier caps.
May 18, 2018
Removal of faulty concrete on pier 5 continues. Next week patches will be repaired on pier 5 and they will continue to form pier 3 to prep for pouring. The contractor will also work on cutting groves in the columns for the wires and drill holes for the anodes which are part of the cathodic protection.
April 12, 2018
Construction on the Benton Street Bridge Project continues on Pier 4, which is adjacent to the eastern edge of the railroad track. In order to protect the track, plywood catchers were installed to minimize the amount of falling debris. Additionally, three shoring columns were installed on the bridge concrete beam to ensure safety. A comprehensive survey was done by City staff of the railroad track to ensure that the track is properly restored at the end of the project.
April 6, 2018
Construction on the Benton Street Bridge Project continues on Pier 1 and 2. These steel columns will be used to shore up the bridge to strengthen it while unsound material is removed. Finally, the contractor installed a camera system so the construction team can monitor the construction process.
March 29, 2018
Construction on the Benton Street Bridge Project has started this week. The bridge has 12 piers; the work so far has been on pier 1 and 2 on the east side of the bridge. Accomplishments this week have been the erection of shoring, testing of the bridge concrete piers, and beginning of removing the unsuitable material.