Time and the environmental factors within industrial plants are significant contributors to the degradation of concrete structures. Without regular inspections and maintenance, these structures can become safety hazards and lead to unplanned downtime.

An FCC Unit, also known as a “cat cracker”, located in a Mid-Western refinery had visible signs of deterioration on the structural steel frame. The conditions observed included corrosion of the steel, failed coatings and delaminated fireproofing.

Based upon the success of past projects, the owner contracted with STRUCTURAL using Investigate-Design-Build (IDB) project delivery. IDB is a turnkey approach that includes evaluation of the structure, solution and design development, and field construction of repairs.

With a scheduled turnaround approaching, STRUCTURAL and its engineering partner STRUCTURAL TECHNOLOGIES, performed a condition assessment of the Cat Cracker. Using non-destructive and semi-destructive testing, the Cat Cracker and supporting pipe racks were evaluated to determine the level of degradation. Based upon these results a repair plan was developed and designed for work to take place during the upcoming turnaround.

STRUCTURAL mobilized and implemented the repairs, which included full and partial depth concrete repairs, fireproofing, and full structural steel replacement. Because of the integrated approach using IDB, a large portion of the repair work was completed pre-turnaround, saving the plant time and money. The project was safely and successfully completed, and the potential risk was mitigated effectively using IDB delivery.