Post Tension Cable Slab Foundation
A post tensioned foundation is a concrete slab foundation that is reinforced with stranded steel cables that are tensioned after.
Post tension cable slab foundation. The post tensioning institute designed post tensioned foundations. Post tensioned slabs are thinner and lighter which have trickle down effects on the both the building gravity and lateral force resisting systems including columns shear walls and foundations. A post tension slab is a slab of concrete that has been pre stressed using a specific method to increase the strength of the concrete. As a result it s best to construct a post tensioned slab giving the slab the strength to resist stresses caused by the soil.
A post tension slab is a concrete slab that has steel cables running through it that have been placed under 33 000 pounds of tension. The home builders theory is that they can achieve a minimum of 50 psi pounds per square inch compression throughout the slab and most importantly at the middle of the. We specialize in elevated and slab on grade post tensioning and post tension repair work for both commercial and residential applications in dallas fort worth arlington keller plano mansfield and throughout the dfw metroplex texas oklahoma colorado louisiana and new mexico. A primer a basic concept to understand is that concrete is strong in compression and weak in tension.
Many modern homes are built on post tension slab concrete. Flexural cracks develop when. Campbell the post tension cable system for concrete slab foundations that has and is replacing the standard steel rebar system has a fundamental flaw. Errors that lead to cracks in post tensioned slabs.
Construction of post tensioned slabs on grade is very similar to using reinforcing steel except for the tensioning step. When errors are made on site during the post tensioning process the ability of the reinforcement to prevent cracking is decreased. Foundation repair of post tension foundation including cables. Cables are arranged as indicated by the engineer and chaired to run through the center of the slab.
This tension makes the concrete slab and foundation much stronger than concrete without reinforcement and helps reduce cracking. Several methods exist for pre stressing concrete with post tensioning being a very common one. For residential construction tendons at 48 inches on center are common.