Manual mechanical prestressing system of thin shallow curved slab

A manual mechanical prestressing system was manufactured which used to apply a post-tension force to the high-stress steel wires in the curved slab member. The study aims to experiment with the use of a mechanical prestressing technique of thin curved sections to assess the prestressed force influencing the behavior of a curved slab at the initial and final loading stages. Two advantages achieved in the system; pulling the steel wires at all positions simultaneously and application of the pulling force perpendicular to the cross-section of the curved slab. To check the efficiency of the prestressing system, two reactive powder concrete curved slab members were cast and tested under a uniformly distributed load. The first one is reinforced with micro steel fibers while the second one is reinforced with micro steel fibers in addition to four high-stress steel wires. The experimental results showed the applicability and facility of using this manual mechanical system to perform the post-tension forces of thin curved slabs. Applying the post-tension prestressing force in the curved slab member increased the cracking and ultimate loads to about 311% and 381% respectively compared to the non-prestress curved slab, whereas the failure mode was occurred by flexural-tensile stress near the edge beams for both curved slabs. (paper)