Construction and Stressing sequence of PT slabs


  • The soffit of the slab shall be marked directly below each duct.
  • Stressing can commence when the specified transfer strength, minimum of 25 MPa has been reached (single phase stressing)
  • Stress all PT tendons not exceeding 80% of the characteristics strength of tendon. Additional consideration is to be given to safety and tendon load/extension characteristics as per clause 4.7.1-section 4-BS8110-1
  • Stressing sequence of strand within a duct to be:
  • In general band beam tendons shall be stressed first, then slab tendons, unless noted otherwise.
  • Stressing sequence may only continue when specified concrete strength at that stage has been achieved.
  • Grout tendons after cable extensions have been approved by the structural engineer.
  • Stressing recesses and pockets:
  • After grouting, the temporary sealing mortar is to be removed where applicable, form sides and bottom faces of recesses and fill with well vibrated stiff concrete mix.



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