STP ShaliMulsion A / C / P
Cold-applied anionic, cationic and polymer-modified bitumen emulsions for tack coats, patching and cold mix asphalt work — laid without a boiler or a hot-mix plant on site.
What is it?
A family of three cold-applied bituminous emulsions — ShaliMulsion A (anionic), C (cationic) and P (polymer-modified) — each offered in Rapid, Medium and Slow Setting grades for different road jobs.
Where is it used?
Highway and PWD road resurfacing, rural road works, township and parking-area roads, utility trench reinstatement, and cold mix asphalt patch repair.
Why use it?
Applied cold, so sites skip the boiler and hot-mix plant, cut fuel and labour cost, avoid the fire hazard of heated bitumen, and can still work through most of the monsoon.
How is it applied?
Sprayed or brushed onto a cleaned, dampened surface as a tack or prime coat, or mixed cold with aggregate for patching; tools are rinsed with water before the emulsion ‘breaks’ and turns black.
About STP ShaliMulsion A / C / P
STP Limited has traded construction chemicals in India for eight decades, and ShaliMulsion is one of its most utilitarian families — a cold bitumen emulsion built for the realities of Indian road sites rather than a lab bench. A contractor draws it straight from a drum or tanker instead of firing up a boiler, and it does its job as it “breaks” on contact with aggregate. The line has three chemistries: ShaliMulsion A, anionic, tested to IS 3117:2004; ShaliMulsion C, cationic, tested to IS 8887:2004 and ASTM D2397-02; and ShaliMulsion P, polymer-modified, tested to the EN 13808 series of methods. Each of those comes in Rapid, Medium or Slow Setting, so what a site actually orders is one of several combinations chosen against the aggregate and the job.
The choice isn’t cosmetic. Anionic ShaliMulsion A suits electropositive stone such as limestone and marble and prefers warm, dry weather; cationic ShaliMulsion C bonds a wider range of aggregate, including the granite and quartzite common on Indian highways, and tolerates more weather; ShaliMulsion P layers polymer modification onto that cationic base for better elastic recovery on heavier-traffic stretches. As an authorised STP distributor and applicator for Delhi NCR and pan-India project supply, Space Arc Engineering stocks ShaliMulsion alongside STP’s wider road-surfacing range and helps contractors match grade to aggregate before a drum is opened on site.
The technical insight
The A/C/P split comes down to electrochemistry. An emulsifier keeps bitumen droplets apart by giving them a surface charge; when contact with aggregate neutralises that charge, the droplets coalesce and the emulsion “breaks,” bonding bitumen to the stone. Anionic ShaliMulsion A carries a negative charge, so it bonds best to electropositive minerals like limestone and marble. Cationic ShaliMulsion C carries a positive charge, which is why it grips the electronegative, silica-rich aggregate that most Indian quarries produce, and why practice generally leans cationic for highway work. ShaliMulsion P keeps that cationic charge but adds polymer to the base bitumen before emulsification, lifting softening point and elastic recovery beyond plain A/C — properties tested to EN methods rather than the IS methods used for A and C. The Rapid/Medium/Slow Setting split, in turn, is a viscosity and demulsibility control: RS grades are formulated to break within minutes of spraying, MS grades resist breaking on contact so they stay mixable with coarse aggregate, and SS grades are stable enough to survive dilution for slurry and fog-seal work.
Where it is used
- Tack coat between an existing bituminous layer and a fresh asphalt overlay, using Rapid Setting grade
- Prime coat and surface dressing over WBM (water-bound macadam) bases before surfacing
- Cold Mix Asphalt (CMA) patch repair of potholes and edge failures without a hot-mix plant
- Grouting and sealing of pavement formations and sub-bases ahead of construction
- Soil stabilisation work, typically with the anionic ShaliMulsion A grade
- Slurry surfacing and fog seals using diluted Slow Setting grade
- Dust palliative treatment on unpaved haul roads and rural stretches
- Lean-mix curing and patching on internal roads, yards and parking areas
Key advantages
- Cold-applied — no boiler or hot-mix plant on site, saving fuel, labour and the fire risk of heated bitumen
- Works in most Indian weather including light rain, short of frost or a heavy downpour
- Three chemistries (A/C/P) let a site match emulsion charge to its actual aggregate for real adhesion
- Three setting speeds (RS/MS/SS) cover tack coats through to slurry seals inside one product family
- Tested to IS 3117:2004, IS 8887:2004, ASTM D2397-02 and EN 13808-series methods across the grades
- Stays fluid until it has fully penetrated the aggregate mass, so crews aren’t tempted to over-dose bitumen
- Non-toxic and pollution-free relative to hot bitumen handling, per the manufacturer’s data sheet
- Polymer-modified P grade adds elastic recovery and a higher softening point for heavier-traffic stretches
Limitations & considerations
- Grade selection isn’t optional — the wrong A/C choice for a given aggregate genuinely weakens adhesion
- Cannot be used in frost or heavy downpour, and must never be heated, which narrows the working window
- Two ShaliMulsion types or grades must never be mixed together, or the emulsion coagulates
- Sprayers, brushes and tools must be rinsed with water before the emulsion sets, or they’re effectively lost
- It is a road/pavement bituminous binder, not a roof or basement waterproofing membrane, despite the STP name
- Sold in bulk tankers and 200 kg drums, sized for contractor and project-scale road work, not small DIY jobs
Selection & best practice
Match the grade to the job before opening the drum: Rapid Setting for a fast-gripping tack coat, Medium Setting for premix and surface dressing, Slow Setting (diluted where needed) for prime coats and fog seals — and default to cationic C or polymer-modified P for the granite and quartzite common on most Indian projects, reserving anionic A for genuinely limestone or marble aggregate. Clean the surface of loose material and dampen it lightly before spraying. Never heat ShaliMulsion and never mix two grades or types together. Keep traffic and foot movement off the treated area until it has visibly “broken” and turned black, and rinse tools with water before that happens. Store drums sealed, under cover, between 5°C and 35°C, protected from frost, and roll them before drawing emulsion so settled solids remix. On an unfamiliar aggregate source, run a small trial patch first — the manufacturer’s own coating-ability rating drops from “Good” to “Fair” on wet aggregate, so site conditions matter more here than with a hot-applied binder.
Specifications
| Chemistry / grades | ShaliMulsion A – Anionic; ShaliMulsion C – Cationic; ShaliMulsion P – Polymer-modified (cationic base) |
| Setting speed ranges | Rapid Setting (RS), Medium Setting (MS), Slow Setting (SS) — offered across all three chemistries |
| Governing standards | IS 3117:2004 (ShaliMulsion A); IS 8887:2004 and ASTM D2397-02 (ShaliMulsion C); EN 13808-series test methods (ShaliMulsion P) |
| Bitumen/binder content | 57–67% by mass, min., depending on grade (per IS 3117/8887 annexures) |
| Particle charge | Negative (ShaliMulsion A); Positive (ShaliMulsion C and P) |
| Viscosity (Saybolt Furol) | Approx. 20–100 SFS at 25°C for most RS/SS grades; MS grades up to ~450 SFS at 50°C (ASTM D2397-02) |
| Storage/settlement stability | Max. 3% settlement in 5 days (IS); max. 1–2% in the 24-hour storage stability test |
| Sieve residue (600 micron) | Max. 0.05–0.50% by mass, depending on grade |
| Packing & storage | Bulk tankers and 200 kg HMHDPE/mild steel drums; store sealed, 5°C–35°C, protected from frost |
Industry use cases
Highway & PWD road resurfacing
RS-grade ShaliMulsion as an IS-compliant tack coat before a fresh bituminous overlay, cutting the need for an on-site boiler.
Rural road contracting
Cold Mix Asphalt patching of potholes and edge breaks on rural stretches where a hot-mix plant isn’t practical to mobilise.
Township & industrial internal roads
Prime coat and surface dressing over WBM base for internal roads, yards and parking areas in townships and industrial parks.
Pipeline & utility trench reinstatement
Sealing and grouting of formations and sub-bases when a trench is reinstated after utility work.
EPC & highway contractors on international-spec projects
Specifying polymer-modified ShaliMulsion P where the contract cites ASTM D2397 or EN 13808-series testing for better elastic recovery.
Frequently asked questions
What’s the actual difference between ShaliMulsion A, C and P?
Which setting speed — RS, MS or SS — should I order?
Can ShaliMulsion be applied during the monsoon?
What application rate or coverage should we plan for?
How is it packed, and how should we store a drum?
Can we use ShaliMulsion as a rooftop or basement waterproofing coating?
How we position STP ShaliMulsion A / C / P
ShaliMulsion sits in STP’s Road Surfacing business line, alongside ShaliBond bonding agents and the ShaliCryl/ShaliSBR polymer emulsions, and is distinct from STP’s building-side waterproofing range such as ShaliCem and ShaliPlast — though all of it ships under the same STP Limited name. As an authorised STP distributor and applicator, Space Arc Engineering supplies and specifies ShaliMulsion for Delhi NCR and pan-India road and infrastructure projects, and can pair it with STP’s own repair and grouting materials for a single-brand road package. Fosroc’s India range is built around structural repair, concrete admixtures, waterproofing and flooring chemistry rather than road-grade bituminous emulsions, so it isn’t a genuine like-for-like substitute here; contractors comparing options for tack coats and cold mix binders typically look at other dedicated bitumen-emulsion suppliers instead. Where a project actually needs a building-side waterproofing membrane rather than a road binder, Space Arc points to STP’s own waterproofing range instead of reaching for ShaliMulsion.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.