"Un-bonded post-tensioned (PT) reinforcement in waffle slabs has been popularly used in parking structures for many decades. Its use greatly reduces the amount of cracking and possible leakage in the structure and also allows economical long-span construction.

The boom of the construction of waffle slabs in the United States began in the 1970s. However, many of the early PT structures have since been encountered in a deteriorated condition with varying degrees of damage to the PT systems.

This article explains the deterioration mechanisms that affect post-tensioned waffle slabs and, more specifically, addresses sheathing strand systems. A case study illustrates the detrimental effects of deterioration mechanisms on PT structures, providing specific repair recommendations in order to mitigate and prevent structural related problems for un-bonded post-tensioned waffle slabs..."