Sika Sikadur-31 SBA S-09 IN
A hot-weather grade, high-modulus epoxy paste that bonds match-cast precast segments into watertight, load-transferring joints for viaducts, flyovers and metro bridge decks.
What is it?
A two-part, thixotropic epoxy segmental bridge adhesive (SBA) supplied as a pre-batched Part A resin and Part B hardener that cure to a concrete-grey paste.
Where is it used?
Match-cast joints between precast concrete segments in balanced-cantilever and span-by-span bridge decks, metro viaducts and elevated corridors.
Why use it?
It develops high early strength and a high modulus, transfers compression and shear across the joint, and stays watertight, making segment erection fast and structurally continuous.
How is it applied?
Mix the full 3:1 unit, trowel a thin non-sag layer onto both mating faces, then post-tension the segments together within the open time to squeeze out a thin, uniform glue line.
About Sika Sikadur-31 SBA S-09 IN
Sikadur-31 SBA S-09 IN is Sika’s segmental bridge adhesive engineered specifically for the joints between match-cast precast concrete segments. In modern precast bridge construction, each segment is cast against its neighbour so the two faces mate perfectly. On site those faces are glued together with a structural epoxy and immediately stressed with post-tensioning tendons. The adhesive is not a cosmetic sealer; it is the medium that fills the micro-gaps in the joint, lubricates the segment during positioning, transfers shear and compression once cured, and keeps water and chlorides out of the tendon ducts for the life of the structure. The S-09 IN grade sits within a temperature-graded family, formulated for the higher substrate temperatures common on Indian sites, with a working window suited to roughly +20 to +50 degrees C.
For engineers and erection contractors, the appeal is predictability under pressure. The paste is thixotropic, so a 2 to 3 mm layer stays put on a vertical or overhead segment face instead of slumping. It bonds to dry or damp concrete without a separate primer, tolerates the moisture that is unavoidable on real construction joints, and cures without shrinkage so the glue line does not open up. Strength gain is deliberately quick: enough compressive capacity builds within hours to allow tendon stressing to schedule, while the seven-day figures confirm the joint’s long-term structural performance. Supplied as a pre-weighed 6 kg unit, it removes the site guesswork of proportioning two components by hand and keeps every mixed batch on-ratio.
The technical insight
The behaviour that matters in a segmental joint is high modulus combined with high early strength, and this is where the S-09 IN formulation is tuned. A segmental bridge works as a series of precast blocks held in compression by post-tensioning. When the tendons are stressed, the adhesive in the joint is squeezed to a very thin film and must behave almost as stiffly as the concrete around it, otherwise the joint would creep and the prestress would drift. An instantaneous modulus of elasticity of around 13,000 N/mm2 keeps the cured film stiff enough to act with the segments rather than as a soft interlayer. The epoxy chemistry, filled with selected mineral fillers, is what delivers this stiffness together with a compressive strength of roughly 60 N/mm2 at 24 hours climbing to at least 75 N/mm2 at seven days. Because the resin is moisture-tolerant, it displaces the thin film of water on a damp face and still develops a full chemical bond, which is why no primer is needed. The thixotropic, non-sag rheology comes from the filler system and is what lets a thin bond line be held on a vertical face during the minutes between buttering the segment and locking it in with the tendons.
Where it is used
- Bonding match-cast precast concrete segments in balanced-cantilever bridge decks
- Span-by-span erection of precast box-girder viaducts on gantries
- Metro and elevated-corridor viaduct segment jointing
- Flyover and grade-separator precast segmental superstructures
- Coastal and marine bridge crossings where chloride tightness of the joint is critical
- Desert and hot-climate projects where high substrate temperatures rule out normal-set grades
- Structural bonding of hardened concrete to hardened concrete in precast assembly
- Filling and sealing fine gaps at segment interfaces to create watertight, load-bearing joints
Key advantages
- High instantaneous modulus of around 13,000 N/mm2 keeps the thin joint stiff and compatible with the concrete
- Rapid early strength (about 60 N/mm2 at 24 hours) lets post-tensioning proceed to programme
- Thixotropic and non-sag, so a thin layer holds on vertical and overhead segment faces
- Moisture-tolerant and bonds to dry or damp concrete without a separate primer
- Cures with negligible shrinkage, so the glue line stays closed and watertight
- Formulated for high ambient and substrate temperatures typical of Indian summer sites
- Pre-batched 3:1 unit removes on-site proportioning error and keeps every mix on-ratio
- Meets recognised FIP, BS and ASTM (C-881 Type VI) segmental adhesive requirements
Limitations & considerations
- Grade-specific: S-09 IN is matched to a hot-weather window (approx +20 to +50 degrees C); cooler conditions need a different grade in the range
- Pot life is short at high temperature (around 30 minutes per 100 g at +50 degrees C), so mixed material must be applied and stressed quickly
- Not a general-purpose gap filler or bonding agent; it is designed for structural match-cast segment joints
- Segment faces must be sound, match-cast and free of laitance, oil and loose material for full bond development
- Post-tensioning must follow while the joint is still within its open time, demanding tight erection coordination
- Being a filled epoxy, it will not bridge poorly matched or badly formed joint faces that leave a thick, uneven gap
Selection & best practice
Confirm the grade against the expected substrate temperature before ordering; S-09 IN is the hot-weather choice and should not be used outside its window. Store the units in shade and, on very hot days, keep them cool before mixing to protect the pot life. Prepare both mating faces so they are sound, match-cast and free of laitance, curing compound, oil and standing water; a damp face is acceptable but pooled water is not. Mix the entire pre-batched 6 kg unit fully to a uniform concrete-grey colour with no streaks, never a part-unit, so the 3:1 ratio is preserved. Trowel a thin, even layer onto both faces, position the segment and begin post-tensioning within the open time so the excess adhesive is squeezed to a thin uniform film and full bearing is achieved. Check that adhesive extrudes continuously around the joint perimeter as confirmation of complete coverage, and clean tools with solvent before the epoxy sets.
Specifications
| Product type | Two-part thixotropic epoxy segmental bridge adhesive (SBA) |
| Mixing ratio | Part A : Part B = 3 : 1 by weight |
| Pack size | 6 kg pre-batched unit (Part A 4.5 kg + Part B 1.5 kg) |
| Colour | Concrete grey when mixed (Part A off-white, Part B black) |
| Application / substrate temperature | Approx. +20 degrees C to +50 degrees C (hot-weather grade) |
| Pot life | About 30 minutes per 100 g at +50 degrees C |
| Compressive strength | About 60 N/mm2 at 24 hours; at least 75 N/mm2 at 7 days |
| Shear strength | Around 12 N/mm2 at 7 days |
| Instantaneous modulus of elasticity | Around 13,000 N/mm2 |
Industry use cases
Metro rail viaducts
Jointing precast box-girder segments during span-by-span or cantilever erection of elevated metro corridors, keeping the programme on gantry cycle times.
Highway flyovers and grade separators
Bonding precast segmental superstructures for urban flyovers where fast, watertight, load-transferring joints are essential.
Coastal and marine bridges
Sealing segment joints against chloride and water ingress on sea crossings and estuarine bridges to protect internal tendons.
Desert and high-temperature projects
Erecting precast bridge decks in hot-climate regions where the S-09 grade’s high-temperature working window suits the ambient conditions.
Long-span river crossings
Providing stiff, high-modulus joints in balanced-cantilever bridges where segment continuity under prestress governs deck behaviour.
Frequently asked questions
What does the S-09 IN suffix mean on Sikadur-31 SBA?
Do I need a primer before applying it?
How quickly can I post-tension after gluing the segments?
Can it be used as a general concrete bonding agent or gap filler?
What is the coverage from one 6 kg unit?
Does Space Arc supply it Pan-India with application support?
How we position Sika Sikadur-31 SBA S-09 IN
Within the Sika range, Sikadur-31 SBA S-09 IN is the hot-weather grade of a temperature-graded family; if your site temperatures are lower, a cooler-climate grade of the same Sikadur-31 SBA line is the correct choice, so specify by expected joint temperature. For adjacent structural work on the same bridge, the wider Sikadur epoxy family covers crack injection and general structural bonding, and Sika’s post-tensioning duct grouts complement the tendon works that follow segment jointing. Across our other brands, we can pair the segment adhesive with protective anti-carbonation and anti-corrosion coatings for the finished deck and pier surfaces. For teams that standardise on Fosroc, a directly comparable segmental bridge adhesive is available, so specifiers can match to their approved-vendor list without changing the joint concept.
Fosroc Nitobond SBA — Choose the Fosroc option when the project or client specification is standardised on Fosroc’s approved-vendor list, as Nitobond SBA is a directly comparable temperature-graded epoxy segmental bridge adhesive for match-cast joints.
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