Re-entrant corner using straight formwork panels

 

This method describes the construction of a re-entrant corner in a GBE wall using straight formwork panels.

To make the method shown in this document easier to understand, the insertion of GBE spacers used with formwork systems incorporating tie rods has intentionally been omitted from the explanatory diagrams.

This method must be adapted as necessary to comply with the installation recommendations, particularly the safety requirements, specified by the suppliers of the equipment and materials used to construct a GBE wall.

Phase 0:

  • It is recommended to provide a starter at the base of the wall by leaving the concrete facing from the previous lift projecting. This will facilitate positioning of the formwork panels.
Phase 0 - starter at the base of the wall
  • Break back part of the projecting concrete from the previous lift to allow installation of the internal formwork panel.
Phase 0 - preparation for installation of the internal formwork panel

Phase 1:

  • Position the internal formwork panels.
  • Install the structural reinforcement using conventional reinforced-concrete construction methods.
Phase 1 - installation of the internal formwork panels and reinforcement

Phase 2:

  • Position the insulation panels with the GBE components assembled beforehand.
  • Leave an open space at the corner.
Phase 2 - installation of the insulation panels

Phase 3:

  • Position the corner insulation panel.
  • Insert external connectors into the corner panel. Where an external connector does not connect to one of the insulation panels installed previously, fit an internal connector onto it.
Phase 3 - installation of the corner insulation panel and connectors

Phase 4:

  • Install the reinforcement for the external concrete leaf.
  • Position the concrete placing hatch(es).
  • Position the external straight formwork panels and tighten them in accordance with the formwork manufacturer's recommendations.
  • Place the concrete simultaneously on both sides of the insulation, for the external and internal concrete leaves.
Phase 4 - closing the formwork and placing concrete

Phase 5:

  • Strip the formwork.
  • Point of attention: controlling the construction joint at the location where the previous concrete lift was broken back can be more complex.
Phase 5 - formwork removal from the re-entrant corner