Sika Sikadur-31 SBA S-02 IN
Two-part, moisture-tolerant epoxy segmental bridge adhesive formulated for hot-climate match-cast joints between +25 C and +45 C, supplied and supported by Space Arc across Delhi NCR and Pan-India.
What is it?
A two-component, solvent-free, thixotropic epoxy paste that bonds match-cast precast concrete segments into watertight, load-transferring bridge joints.
Where is it used?
Precast segmental bridge and viaduct construction on sites where substrate and ambient temperatures sit between +25 C and +45 C.
Why use it?
It lubricates and seals the epoxy joint while it cures, transfers shear and compression across segments, and hardens without shrinkage even on damp concrete.
How is it applied?
Mix Part A and Part B 3:1 by weight, apply by trowel or gloved hand to both prepared match-cast faces, stress the tendons within the open time, and let the squeeze-out confirm a full joint.
About Sika Sikadur-31 SBA S-02 IN
Sikadur-31 SBA S-02 IN is Sika’s epoxy jointing adhesive for precast segmental bridge decks, and the “S-02 IN” suffix matters: it is the Indian-market grade tuned for a working window of +25 C to +45 C, the substrate temperatures a segment sees on an open casting yard through most of the Indian construction calendar. The product is a two-part system of epoxy resin with selected fillers, supplied in pre-batched 6 kg units so the correct 3:1 ratio is locked in at the factory rather than measured on site. Its job during erection is threefold: it lubricates the mating faces so a segment can be slid and seated onto its shear keys, it fills and seals the joint to keep it watertight, and once cured it transfers compression and shear stresses across the interface as if the two segments were monolithic.
What makes it site-friendly is a deliberately thixotropic, non-sag consistency and genuine moisture tolerance. The paste holds on vertical and overhead faces without slumping, and because hardening is not affected by humidity it can be brushed into matt-damp concrete rather than demanding a bone-dry substrate that is rarely achievable outdoors. The two components are supplied in contrasting colours so the crew can see, by uniform colour, when mixing is complete. It carries no primer requirement, hardens without shrinkage, and is formulated against the FIP/fib acceptance criteria that specifiers cite for segmental construction, with a Bureau Veritas India test report on record. This is a specialist structural product for experienced precast crews, not a general-purpose bonding agent.
The technical insight
The engineering value sits in the epoxy joint itself. In external post-tensioned segmental construction the deck is held in compression by the tendons, and the thin epoxy layer between segments has to do two contradictory things at once. While wet it must stay fluid enough to lubricate and let the shear keys nest, then it must build strength fast enough to be stressed within a working shift. Sikadur-31 SBA S-02 IN is engineered around that curve: at 100 g and +45 C it gives roughly 35 minutes of pot life and about 65 minutes of open time to place and align, then develops a compressive strength of at least 60 N/mm2 by 24 hours and 75 N/mm2 by 7 days at +25 C. Its high instantaneous compression modulus of around 14,000 N/mm2 means the cured film barely deforms under the permanent prestress, so the joint behaves stiffly and shear is transferred cleanly rather than through creep. Bond is validated to 100% concrete failure on wet concrete in both tension and bending at 24 hours, meaning the adhesive is stronger than the parent concrete it joins. Because it hardens without shrinkage (shrinkage held at 0.4% or less) the film does not pull the faces apart or leave a leak path, which is what keeps the joint watertight and the tendons protected from ingress.
Where it is used
- Bonding match-cast precast segments in balanced-cantilever and span-by-span bridge and flyover decks
- Precast segmental metro and rail viaduct erection
- Sealing and stress-transferring the joints of box-girder segments in externally post-tensioned decks
- Lubricating shear keys so segments seat cleanly during dry-run and final assembly
- Creating watertight joints that protect internal or external post-tensioning tendons from water ingress
- Hot-weather and coastal casting yards where substrate temperatures run between +25 C and +45 C
- Overhead and vertical joint faces where a non-sag, thixotropic paste is essential
- Segmental construction on matt-damp concrete where a moisture-tolerant adhesive is required
Key advantages
- Moisture tolerant: bonds to dry or matt-damp concrete and hardens unaffected by humidity
- Thixotropic and non-sag, so it stays put on vertical and overhead joint faces
- Factory pre-batched 3:1 units remove on-site measuring error
- Contrasting component colours give a clear visual check that mixing is complete
- High initial and ultimate strength: at least 60 N/mm2 compressive at 24 hours, 75 N/mm2 at 7 days
- High compression modulus (~14,000 N/mm2) for a stiff, low-creep joint under prestress
- Hardens without shrinkage and stays impermeable to liquids and water vapour
- Formulated to FIP/fib, ASTM and BS criteria for segmental construction, with a Bureau Veritas India test report
- No primer needed, keeping the erection cycle short
Limitations & considerations
- Temperature-specific grade: S-02 IN is only for +25 C to +45 C substrate and ambient conditions; cooler or hotter sites need the matching S-04 IN, S-03 or S-09 IN grade
- Short working window in the heat: about 35 minutes pot life and 65 minutes open time at +45 C, so mixed material must be placed quickly
- For experienced professionals only; correct erection sequencing and tendon stressing within open time are essential
- Substrate must be at least 28-day-old, mechanically prepared, laitance-free open-textured concrete free of standing water, oil and dust
- Long-term structural design load must be kept below roughly 20 to 25% of failure load to allow for creep in all polymer adhesives; a structural engineer must sign off the design
- Cured epoxy can only be removed mechanically, so tools must be cleaned with Sika Colma Cleaner immediately after use
Selection & best practice
Confirm the substrate and ambient temperature are genuinely within the +25 C to +45 C band before choosing S-02 IN; if the yard is cooler or hotter, switch to the correct grade in the range rather than forcing this one. Prepare both match-cast faces by abrasive blasting to an open-textured, laitance-free profile and remove all dust; concrete must be at least 28 days old and either dry or matt-damp with no standing water, and the substrate must sit at least 3 C above dew point. Mix full units only: stir Part A briefly, add Part B and mix continuously for at least three minutes to a uniform colour, then decant and mix a further minute, avoiding over-mixing that entrains air. Only mix what can be used within the pot life, and never open the next unit until the previous one is placed. On matt-damp concrete brush the adhesive well into the surface, apply to both faces, then close and stress the joint so a continuous bead of squeeze-out confirms a full, void-free joint. Clean tools with Sika Colma Cleaner immediately, before the epoxy hardens.
Specifications
| Chemical base | Two-part epoxy resin with selected fillers, solvent-free |
| Mixing ratio | Part A : Part B = 3 : 1 by weight (factory pre-batched) |
| Colour | Part A off-white, Part B black, mixed concrete grey |
| Density (mixed) | 1.9 plus/minus 0.1 kg/L at +30 C |
| Application / substrate temperature | +25 C min. to +45 C max. |
| Pot life / open time | ~35 min / ~65 min (100 g mass at +45 C) |
| Compressive strength | >=60 N/mm2 at 24 h; >=75 N/mm2 at 7 days (+25 C) |
| Shear strength | >=12 N/mm2 (7 days / +25 C) |
| Modulus of elasticity | ~14,000 N/mm2 instantaneous (compression) |
| Shrinkage / max layer thickness | <=0.4% (7 days / +45 C); 30 mm max. thickness |
| Packaging / shelf life | 6 kg pre-batched unit (4.50 kg + 1.50 kg); 12 months, stored +5 C to +40 C |
Industry use cases
Highway & Expressway Flyovers
Jointing precast box-girder segments in balanced-cantilever and span-by-span decks on hot-climate expressway projects across Pan-India.
Metro & Rail Viaducts
Erecting precast segmental viaducts where fast, watertight joints keep the erection cycle moving and protect the post-tensioning tendons.
Coastal & Marine Bridges
Sealing segment joints against water and vapour ingress in humid, high-temperature coastal environments where its moisture tolerance is decisive.
Precast Yards & Casting Sites
Match-cast segment assembly in open yards through the Indian summer, where the +25 C to +45 C grade suits real substrate temperatures.
Post-Tensioned Segmental Decks
Transferring shear and compression across externally post-tensioned segments with a stiff, low-creep, shrinkage-free epoxy joint.
Frequently asked questions
What does the S-02 IN grade mean, and how do I pick the right one?
Can it be applied to damp concrete?
How long do I have to work with it once mixed?
What strength does the cured joint reach?
Does it need a primer, and how is it packed?
Is Space Arc an authorised Sika supplier, and do you support application?
How we position Sika Sikadur-31 SBA S-02 IN
Sikadur-31 SBA S-02 IN sits within Sika’s segmental bridge adhesive family, and choosing the correct temperature grade matters more than the brand: pair it with S-04 IN for cooler +10 C to +20 C work, S-03 for +15 C to +35 C, or S-09 IN for hot +20 C to +50 C sites. On the same projects Space Arc typically supplies Sika’s structural range alongside it, including Sikadur epoxy anchoring and bonding grades, SikaGrout cementitious grouts for bearings and pedestals, and Sika post-tensioning and expansion-joint systems. Where a client’s approved vendor list or commercial preference points to Fosroc, we also stock the directly equivalent Fosroc segmental bridge adhesive, so we can specify either brand to match the project’s technical and procurement requirements.
Fosroc Nitobond SBA — Choose the Fosroc option when the project’s approved vendor list, tender specification or commercial preference calls for Fosroc, as Nitobond SBA is a directly equivalent two-part epoxy segmental bridge adhesive.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.