Condition Assessment of Antenna Mast and Guy Anchor Concrete Foundations Constructed in 1988

After 35 years of service, the condition of the mast and guy anchor concrete foundations supporting a tall antenna structure was evaluated in the present study. A visual examination was conducted to classify the severity of the concrete damage, and ultrasonic pulse velocity and half-cell potential measurements were taken to examine the integrity of the concrete and levels of corrosion of the steel bars. A long crack was observed in the corner of the pedestal and spread through the near vertical faces of the foundation of the mast. Concrete delamination and spalling, as well as cracks, were seen on the mast and guy anchors at several locations. Core samples were carefully extracted from the concrete foundations of the mast and anchor guy, and multiple tests were performed in the laboratory. Their average compressive strength was found to be 57 and 60 MPa, respectively, and the levels of water absorption and penetration of chloride ions within such concrete structures were well within acceptable limits. These findings highlight that the initiation of cracks was not due to the quality of the concrete. Repair techniques such as epoxy injection and chicken wire mesh reinforcement were suggested to the client to improve the useful life of the structure and to avoid further propagation of cracks.