A method of forming a post-tensioned concrete member comprising: positioning a post-tensioning tendon within a concrete form , the post-tensioning tendon including a tension member , fixed anchor , and a stressing end anchor ; positioning a pocket former between the stressing end anchor and the concrete form , the pocket former including: a pocket former body , the pocket former body having an outer surface , the pocket former body having a tension member channel therethrough; and a collapsible element , the collapsible element formed on the outer surface of the pocket former body , the collapsible element extending radially outwardly from the pocket former body ; inserting the tension member through the tension member channel of the pocket former body ; placing concrete into the concrete form such that the post-tensioning tendon and the pocket former are encased in the concrete ; applying force to the pocket former body ; collapsing the collapsible element toward the pocket former body ; and forming a cavity within the concrete by removing the pocket former body from the concrete ; optionally, further comprising after forming a cavity : applying tensile stress to the tension member ; and filling the cavity with filling material, the method being characterised in that the pocket former further comprises pocket former bridges , and in that the method further comprises: applying force to the pocket former bridges ; and separating the pocket former body into two or more segments. positioning a post-tensioning tendon within a concrete form , the post-tensioning tendon including a tension member , fixed anchor , and a stressing end anchor ; positioning a pocket former between the stressing end anchor and the concrete form , the pocket former including: a pocket former body , the pocket former body having an outer surface , the pocket former body having a tension member channel therethrough; and a collapsible element , the collapsible element formed on the outer surface of the pocket former body , the collapsible element extending radially outwardly from the pocket former body ; a pocket former body , the pocket former body having an outer surface , the pocket former body having a tension member channel therethrough; and a collapsible element , the collapsible element formed on the outer surface of the pocket former body , the collapsible element extending radially outwardly from the pocket former body ; inserting the tension member through the tension member channel of the pocket former body ; placing concrete into the concrete form such that the post-tensioning tendon and the pocket former are encased in the concrete ; applying force to the pocket former body ; collapsing the collapsible element toward the pocket former body ; and forming a cavity within the concrete by removing the pocket former body from the concrete ; optionally, further comprising after forming a cavity : applying tensile stress to the tension member ; and filling the cavity with filling material, the method being characterised in that the pocket former further comprises pocket former bridges , and in that the method further comprises: applying tensile stress to the tension member ; and filling the cavity with filling material, the method being characterised in that the pocket former further comprises pocket former bridges , and in that the method further comprises: applying force to the pocket former bridges ; and separating the pocket former body into two or more segments. <EOS>