Technical Specifications:
- Item: ST12
- Stitch Description: Engineered anchor stitch structural system
- Installation Spacing: 1-stitch per foot of crack -typical
- Stitch Tensile Strength: 60,000 psi
- Anchor: 2 1/2 ” Custom Sleeve Type
- Horizontal Dimensions: 13-1/4” long by 1-1/4”
- Bridge Length: 12” overall length extending 6” on each side of fracture
- Hook Length: 2-1/4” wedged into concrete
- Anchor Length: 2-1/4” wedged into concrete
- Wedge Mechanism: Precision machined case hardened 1018 steel
- Bridge Material: A-706 rebar
- Niche: Saw Cut 14-1/2” long by 1-3/8” wide by approx. 1-1/2” deep
Technical Summary:
To correct cracking of a beam or slab the American Concrete Institute (ACI 224.1R-07) outlines post-tensioning anchor stitching as desirable to strengthen the fractured area. As with any repair, the extent and cause must be identified and addressed. The TorqueStitchTM technique uses post-tensioning rebar stitches, anchored into solid concrete to bridge the crack and apply a compressive force over the fracture. Post-tensioning is achieved by tightening the anchor on the machined wedge applying force along the 12-inch long stitch and rebar hook. The stitches bridge the crack by extending into the unaffected areas well into solid reinforced concrete. The tensioning mechanism is engineered to provide sufficient tension across the affected area while minimizing migration to other parts of the slab. When stitches are anchored into the rebar web cement areas, fewer loads are exerted on the weak surface substrate and are transferred into actual reinforced areas to restrain future movements.