Repair Systems — Concrete & Structural Defects

Concrete crack stitching

Technical product reference for crack stitching across dormant structural cracks in concrete — proprietary carbon-fibre stitches and custom-fabricated austenitic stainless staples/dowels bonded with a structural epoxy to re-establish tensile continuity. Stitch size, number, spacing and embedment are engineer-determined to ACI 224.1R / AS 3600.

3
Products covered
Dormant / structural
Crack condition
Engineer-determined
Sizing basis
ACI 224.1R / AS 3600
Standard

When crack stitching is the right choice

Crack stitching re-establishes tensile continuity across a dormant structural crack by anchoring stitches — proprietary carbon-fibre stitches or custom-fabricated austenitic stainless staples/dowels — across the crack plane, bonded with a structural epoxy. It is specified where the loss of tensile continuity across the crack reduces the element capacity and the crack is confirmed dormant. Stitching is frequently paired with epoxy injection: injection re-bonds the crack faces, and the stitches carry tension across the plane.

Sizing is engineer-determined — there is no crack-width → size table

Crack stitching is not specified from a crack-width lookup. Proprietary carbon-fibre stitch spacing follows the manufacturer detail within an engineer’s design; custom stainless staples/dowels are fabricated and bonded entirely to the engineer’s specification. In all structural cases the stitch size, number, spacing and embedment are designed by a structural engineer to ACI 224.1R / AS 3600. Steel stitches/dowels are bonded with a structural epoxy anchoring adhesive — see the Epoxy anchoring adhesives reference.

Product Reference

Individual products — one card each — scroll to view all

3 products2 visible, scroll for more

Ardex Australia (Rhino)

Ardex Concrete Crack Lock (CCL)

Carbon-fibre crack-bridging stitch for concrete

Ardex Concrete Crack Lock (CCL) is a carbon-fibre crack-bridging stitch used to re-establish tensile continuity across dormant cracks in concrete. The stitch is bedded into a prepared slot/route and bonded with a structural epoxy. It is a proprietary stitch system — stitch spacing and number follow the manufacturer detail within an engineer's design; all structural cases must be designed to ACI 224.1R / AS 3600. CONFIRM the bonding adhesive, slot detail and installation method against the current Ardex Australia TDS.

Fortress (imported)

Fortress Crack Stitch / StitchDog

Carbon-fibre crack stitch (imported)

Fortress Crack Stitch / StitchDog is an imported carbon-fibre crack-stitching system for re-establishing tensile continuity across dormant cracks. The stitch is bonded into a prepared slot with a structural epoxy. Confirm current Australian availability and all installation and performance detail against the manufacturer TDS. All structural stitching must be designed to ACI 224.1R / AS 3600.

Confirm AU availability

Custom-fabricated (no proprietary brand)

Steel stitching dog / dowel (custom-fabricated)

Austenitic stainless staple / dowel — fabricated to the engineer's detail

A custom-fabricated steel stitching dog or dowel is an austenitic stainless (304 / 316) staple or dowel fabricated to the engineer's detail and bonded across a dormant crack with a structural epoxy anchoring adhesive to re-establish tensile continuity. There is no proprietary product and no size table — staple/dowel size, number, spacing and embedment are subject to engineer specification to ACI 224.1R / AS 3600. The bonding adhesive is selected and installed per its own TDS (see the Epoxy anchoring adhesives page).

System Comparison

Concrete crack stitching — confirm all selections against the current manufacturer TDS before specifying.

Scroll the table sideways to see every column →

ProductTypeMaterialSizing basisBonding mediumStandard
Ardex Concrete Crack Lock (CCL)Ardex Australia (Rhino)Carbon-fibre crack-bridging stitchCarbon fibrePer manufacturer detail / engineerStructural epoxy — CONFIRM (Ardex AU TDS)ACI 224.1R / AS 3600
Fortress Crack Stitch / StitchDogFortress (imported)Carbon-fibre crack stitchCarbon fibrePer manufacturer detail / engineerStructural epoxy — CONFIRM (manufacturer TDS)ACI 224.1R / AS 3600
Steel stitching dog / dowel (custom-fabricated)Custom-fabricated (no proprietary brand)Stitching staple / dowel (fabricated)Austenitic stainless steel (304 / 316)Engineer-specifiedStructural epoxy anchoring adhesiveACI 224.1R / AS 3600

Do not confuse crack stitching with:

  • CFRP laminate strengthening — externally bonded carbon-fibre strips/fabric add flexural or shear capacity to a whole member; crack stitching re-establishes tensile continuity locally across a single crack plane — different function and design basis (ACI 440.2R / AS 5100.8 vs ACI 224.1R / AS 3600)
  • Epoxy injection — low-viscosity epoxy injected into a dormant crack re-bonds the crack faces into a monolithic section; stitching mechanically carries tension across the crack with anchored stitches — the two are frequently paired but are not interchangeable
  • Epoxy anchoring adhesives — anchoring adhesives are the bonding medium used to fix a steel stitch/dowel into drilled holes; they are not the stitch itself — the stitch (carbon-fibre or fabricated stainless) and the adhesive are separate, both required

Disclaimer

This page provides general technical information only. All crack stitching is a structural intervention and must be designed by a structural engineer to ACI 224.1R / AS 3600 — there is no crack-width → size lookup. Final product selection, stitch sizing, spacing, embedment and bonding adhesive must be confirmed against the current manufacturer TDS and the engineer’s design. Do not rely on this reference as a substitute for professional engineering advice.

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