About STP ShaliFix FRM CI

STP ShaliFix FRM CI sits in the Restofix concrete-repair range as the corrosion-inhibiting member of the ShaliFix FRM family. It arrives as a single-component blend of cement, graded aggregates, polymers and selected fibres, needing only clean water on site to become a cohesive, thixotropic mortar. What sets the CI grade apart from a plain fibre-reinforced mortar is the corrosion inhibitor built into the mix. On a typical repair, the reinforcement you expose is already the problem, pitted, rusting and expanding, and a standard patch simply buries that steel again without addressing it. This grade puts an inhibitor in contact with the rebar it encases, so the repair works on the chemistry of corrosion rather than just the geometry of the defect.

For engineers and applicators across Delhi NCR and the rest of India, that combination is genuinely useful on the structures that fail first: marine jetties, coastal balconies, bridge soffits and industrial frames where chloride ingress and carbonation have already set the steel corroding. The polypropylene and steel fibre blend gives the mortar tensile toughness and holds it together through plastic shrinkage, letting it be built up in reasonable thickness on vertical and overhead faces without slumping or formwork. Space Arc Engineering supplies ShaliFix FRM CI as an authorised STP distributor and applicator, so you can source the material, the compatible primers and bonding aids, and site guidance from a single point.

The technical insight

Reinforcement corrodes because chloride ions and carbonation strip away the passive alkaline film that fresh concrete normally maintains around the steel; once that film breaks down, moisture and oxygen drive an electrochemical cell where iron dissolves at anodic sites and the resulting oxide expands, cracking and spalling the cover. A conventional repair mortar restores cover and re-alkalises the immediate zone, but it does little for steel just outside the patch, where a new corrosion cell can form at the interface, the well-known incipient-anode or ring-anode effect. ShaliFix FRM CI addresses this by carrying an inhibitor within the mortar itself: the active component reaches the embedded and adjacent steel and interferes with the corrosion reaction, slowing the rate at which the anodic and cathodic processes proceed. Layered over sound surface preparation and a zinc-rich or cementitious rebar primer, the inhibitor becomes one part of a defence-in-depth strategy rather than a single line of protection. The fibres play a separate mechanical role, bridging micro-cracks and restraining plastic shrinkage so the patch develops its strength without the early cracking that would otherwise re-admit the very chlorides you were trying to keep out.

Where it is used

• Reinstating spalled cover on chloride-contaminated reinforced-concrete columns, beams and slabs
• Repairing bridge and viaduct soffits, piers and crossheads where rebar corrosion has begun
• Patch repairs on marine and coastal structures, jetties, sea walls, splash-zone balconies and parapets
• Rehabilitating industrial structures exposed to aggressive, salt-laden or chemical atmospheres
• Overhead and vertical repairs that must be built up in lifts without shuttering
• Restoring concrete around embedded steel in water-retaining and effluent-handling structures
• Making good after breaking out to expose and clean corroded reinforcement
• Sprayed application over larger repair areas where hand placement would be slow

Key advantages

• Combines structural patching with active rebar corrosion inhibition in a single product
• Single-component, just add clean water, which keeps site batching consistent and mistake-proof
• Fibre reinforcement restrains plastic-shrinkage cracking and adds toughness to the patch
• Thixotropic consistency allows vertical and overhead build-up without formwork
• Good bond to both concrete substrate and prepared steel reinforcement
• Can be placed by hand trowel or by spray, so it scales from small patches to large areas
• Targets the underlying cause of concrete distress rather than only the visible symptom
• Backed by STP’s Restofix repair system, with compatible primers and coatings available through Space Arc

Limitations & considerations

• Not a substitute for proper surface preparation, corroded steel must still be exposed, cleaned to bright metal and primed before application
• The integral inhibitor supplements, but does not replace, mechanical repair and adequate cover to reinforcement
• Placement thickness per lift is limited; deep or full-section reinstatement needs to be built up in layers or reconsidered as micro-concrete
• Being cementitious, it needs proper curing and is sensitive to application in very hot, windy or freezing conditions
• Heavily chloride-laden or structurally deficient members may require cathodic protection or realkalisation that no patch mortar alone can deliver
• Structural repairs should be designed and signed off by a qualified engineer to IS 456 and relevant repair codes

Selection & best practice

Specifications

Industry use cases

How we position STP ShaliFix FRM CI

Within the STP Restofix range, ShaliFix FRM CI is the corrosion-inhibiting choice; where the reinforcement is sound and you simply need a high-strength structural patch or micro-concrete, ShaliFix FRM 40, FRM 70 or ShaliFix MC are the natural siblings, and STP’s own rebar primers and protective coatings complete the system. Across our other brands, similar corrosion-led repairs can be built with Fosroc’s Renderoc high-build mortars paired with Nitozinc rebar primer, Sika’s MonoTop repair range with FerroGard corrosion inhibitors, or MC-Bauchemie’s Nafufill repair mortars, any of which we can specify if your project or client has a preferred brand.

Related Concrete Repair products

View all Concrete Repair products →