About Fosroc Nitomortar TS

Fosroc Nitomortar TS (previously sold as BJ Trans Strip) is a purpose-built epoxy nosing mortar for the most punished part of any bridge — the expansion-joint edge. On a deck, the concrete or asphalt immediately adjacent to a movement joint takes hammering from every axle that crosses, plus water, grit and de-icing chemicals. Plain concrete arrises crack and ravel quickly there, and once the nosing fails the joint seal follows. Nitomortar TS exists to replace that vulnerable edge with a tough, slightly flexible epoxy block — an “armoured nosing” — that takes the impact instead of the structure.

It is supplied as a three-part system: Part A and Part B are the liquid epoxy resin and hardener, and Part C is a graded calcined-bauxite (high-hardness) fine aggregate that gives the cured mortar its abrasion resistance and bulk. Mixed together they produce a black, dense mortar (around 1.7 kg/litre) that develops 25 N/mm2 compressive strength in 24 hours, rising to roughly 70 N/mm2 at full cure, with about 30 N/mm2 flexural and tensile strength. Crucially, it is formulated to absorb impact and resist road salts, petrol, lubricating oils and de-icing chemicals — the cocktail a bridge joint actually sees.

For Indian contractors, consultants and bridge authorities (NHAI, state PWDs, metro-rail and expressway projects), Nitomortar TS is a specialist line item rather than a general repair mortar. It is specified hand-in-glove with Fosroc’s bridge expansion-joint systems — Fosflex, Compression Seal and the A7 system — to form the nosings those joints seat into. Space Arc Engineering, as an authorised Fosroc distributor and applicator across Delhi NCR and Pan-India, supplies it alongside the matching primer (Surface Conditioner P23) and the joint systems so the full nosing assembly comes from one source.

The technical insight

The defining feature of Nitomortar TS is that it is an epoxy mortar tuned for toughness and resilience rather than maximum hardness. Many high-strength repair epoxies are rigid; a rigid nosing on a moving, flexing deck would debond or crack under impact. Nitomortar TS instead trades some peak strength (about 70 N/mm2 at full cure, versus 80-100+ N/mm2 for a structural epoxy grout) for the ability to absorb continual traffic impact without failing at the bond line. The calcined-bauxite aggregate is the second key: it is far harder than ordinary silica sand, so the cured nosing resists the studded-tyre and grit abrasion that strips softer surfaces. The system is also fast: a 30-45 minute setting time at 30 degrees C and 24-hour initial cure mean a lane can be reopened to traffic the next day, which is why it suits night-possession bridge work. Two practical constraints drive site discipline: the application (working) life of the mixed mortar is only 30-60 minutes, and the primer-to-mortar window matters — the nosing must be placed while the P23 primer is still tacky, or the primer must be re-coated. The product is sized for joints not exceeding 65 mm gap width on medium-span decks, with DOE-derived nosing geometry of typically 50 mm deep x 180 mm wide on carriageways.

Where it is used

• Forming armoured epoxy nosings to the arrises of open or sealed expansion joints on bridge and flyover decks (gap width up to 65 mm)
• Building transition strips between an asphalt wearing course and a high-movement surface joint system
• Nosings seating Fosroc Fosflex, Compression Seal and A7 bridge expansion-joint systems
• Reinstating and repairing spalled or raveled joint edges on existing bridges, viaducts and elevated metro/expressway structures
• Nosings on footways and central reservations at reduced geometry (e.g. 100-125 mm wide, minimum 40 mm deep) where traffic is lighter
• Joint-edge protection on structures exposed to de-icing salts, fuel and oil spillage

Key advantages

• Excellent adhesion to correctly prepared concrete and render arrises
• Absorbs continual traffic impact loads thanks to a flexible, resilient cured matrix
• Resistant to road/de-icing salts, petrol, lubricating oils and occasional chemical spillage
• Fast curing — sets in 30-45 minutes at 30 degrees C and reaches initial cure in 24 hours, allowing rapid return to traffic
• High abrasion resistance from the calcined-bauxite aggregate filler
• Negligible shrinkage on curing, so the nosing stays tight to the joint and substrate
• Designed to integrate with Fosroc Fosflex, Compression Seal and A7 joint systems as a complete assembly
• Formulated for tropical climates, suiting Indian ambient temperatures

Limitations & considerations

• Short working window — mixed mortar must be placed within a 30-60 minute application life
• Substrate must be genuinely dry; persistent water in the joint must be eliminated (gas torch if needed) or the nosing will fail
• Requires the matched Surface Conditioner P23 primer, and the nosing must be laid while the primer is still tacky
• Limited to joints not exceeding 65 mm gap width on medium-span decks — not a general-purpose structural repair mortar
• Contains epoxy resins that can cause skin sensitisation; barrier cream/gloves and good site hygiene are required
• Specialist machine mixing (e.g. a Creteangle-type forced-action mixer) is recommended for proper aggregate dispersion
• No water or solvent may be added to adjust workability — stiffness varies with ambient temperature
• Hardened material can only be removed mechanically; tools must be cleaned with Fosroc solvent before cure

Selection & best practice

Specifications

Industry use cases

How we position Fosroc Nitomortar TS

Nitomortar TS sits in a narrow, specialist niche: it is not a general concrete repair mortar like Fosroc’s Renderoc range, but a dedicated bridge-deck joint nosing epoxy. The natural cross-links are to the systems it serves — Fosroc Fosflex, Compression Seal and A7 expansion-joint systems — and to its mandatory companion primer, Surface Conditioner P23. Where a project needs general structural concrete repair around the joint zone rather than the nosing itself, Fosroc Renderoc (cementitious) and Nitomortar FC/Nitomortar S (epoxy repair mortars) are the more appropriate Fosroc lines to specify alongside it. On competitive footing, the closest credible alternatives in India for bridge expansion-joint nosings and edge-protection mortars are Sika’s joint-nosing epoxy systems (e.g. Sikadur-based nosing mortars used with Sika expansion joints) and the joint-and-repair ranges from MBS (MB Solutions) and STP Limited; Dr. Fixit (Pidilite) competes strongly in general concrete repair and waterproofing but is less specialised in heavy-duty bridge joint nosings. For a Fosroc-standard bridge joint where the nosing must match an approved Fosflex/Compression Seal detail, Nitomortar TS remains the system-compatible choice, and Space Arc Engineering can supply it as part of the complete, single-source joint assembly.

Related Concrete Repair products

View all Concrete Repair products →