AC Mitigation – Out of the Box Thinking


An AC Mitigation bid opportunity  brought out the best of Mears’ innovative, “Out of the Box” thinking. The project required the installation of an AC Mitigation System near Sacramento, CA. The design and specifications were provided by the client. The installation called for bare copper cable to be installed in a horizontal column of Conducrete®, a conductive concrete that is often incorporated into Cathodic Protection and AC Mitigation designs where low-impedance grounding is required.

The challenge Mears faced was how to effectively install the Conducrete material to the design specifications, which were complicated by the narrow Right-of-Way, and called for the type of innovative thinking for which Mears is known. From the start of the bidding process it was evident that traditional trenching of the cable and installing the Conducrete in the open trench would not be feasible. The copper cable was required to be centered in a column of Conducrete with specific dimensions. Adherence to these specifications would be verified by both third-party and customer inspectors on site throughout the entire project.

The concept for achieving the AC Mitigation project objectives was loosely adapted from Mears’ patent pending proprietary technique for installing a conductive cable-type linear anode centered in a horizontal column of coke breeze. That process has been used successfully for hundreds of miles of linear anodes throughout the United States. The solution Mears developed for this project involved design and fabrication of a custom piece of equipment for placing the cable and Conducrete as specified. This piece of custom equipment was towed behind the trenching machine, allowing for the copper cable and Conducrete to be installed in a single pass.   If the copper cable and Conducrete were not installed at the same time it would have been difficult to prevent the trench from caving in and nearly impossible to maintain the cable’s centered position during a second pass.

The development of this specialized equipment allowed for a high level of production, and the project was completed on time and on budget.   The successful completion of the work in 2013 led to the opportunity for Mears to perform the second phase of the AC Mitigation project; again the project was completed on time and on budget.

Though the equipment was developed for placing Conducrete, it can be adjusted to handle different types of engineered materials that may be called for in other designs.