Challenge:
An aggregate reaction is causing ongoing degradation of the reinforced concrete structures at this facility. This main pipe rack is one of the more heavily deteriorated structures. The facility operator and regulators asked our team to estimate the margin of safety against collapse.
Resolution:
Our engineering team evaluated the structure in its design condition for current code loads and found that significant margin existed. Upon this conclusion, a second evaluation was performed to capture the structure’s behavior in its deteriorated condition. For this second evaluation, individual section geometries were reduced on account of spalling, loss of rebar and loss of bond between rebar and concrete. Further, boundary conditions were changed and idealized to reflect connection deterioration. It was found that the global structure had some reserve capacity even in its deteriorated state and was not in danger of collapse; however, it was recommended to strengthen some members. Several repair options were considered including concrete repair, FRP and steel augmentation.
