Is the Process Compromising the Service Life of Encapsulated PT?

Unbonded post-tensioned (PT) concrete slab construction is commonly used for many types of structures, from high-rise towers to low-rise concrete podiums and parking structures. Since the adoption of ACI 318-14, Building Code Requirements for Structural Concrete and Commentary, many jurisdictions now require fully encapsulated PT tendons for building applications in all environments to prevent moisture intrusion and improve durability. The effectiveness of full encapsulation, however, can be highly dependent on the PT system installation, specifically the cutting of the tendon tails. This operation may not be done with enough precision and care to protect the grease caps, which encapsulate the tendon tails and complete the PT system’s continuous moisture barriers.