Research aimed toward understanding the underlying mechanics and behavior of curved posttensioned concrete structures subject to prestressing loads (eg, nuclear containment buildings, storage silos, and similar structures) is presented. Previous research focused on radial (ie, out-of-plane normal) stress development has been primarily analytical in nature and there is essentially no experimental research on this topic currently available in the open literature. This study is aimed at producing unique experimental data to gain insight into the effect of localized radial tensile stresses and concrete delamination behavior in curved post-tensioned structures. Three 90 curved post-tensioned concrete wall assemblies (referred to as Specimens 1, 2, and 3) were constructed and tested to delamination failure under monotonically increasing prestressing loads. In an effort to study the influence of wall size-effect, all dimensions of Specimen 2 were doubled those of Specimen 1. In Specimen 3, the size of the maximum aggregate was changed, while the dimensions and nominal design strength of the concrete were maintained. Test results showed a size-effect related influence on the delamination failure loads. Furthermore, it was revealed that the onset and propagation of the delamination cracking loads were affected by the radial stress concentration and specimen size factor. Delamination cracks for all specimens were initiated at compressive stresses which were lower than the allowable stress limit for a service load conditions specified in ASME BPVC Section III, Division 2.