STP ShaliPlast PCE 300-VM
Third-generation polycarboxylate ether superplasticizer with a built-in viscosity modifier — engineered so self-compacting concrete flows through congested steel without bleeding or segregating.
What is it?
A liquid PCE (polycarboxylate ether) superplasticizer from STP Ltd with an integral viscosity-modifying agent (VMA), formulated for self-compacting and high-flow concrete and mortar.
Where is it used?
SCC pours through heavily reinforced sections, precast elements on fast stripping cycles, flowing and sprayed concrete, lightweight-aggregate mixes and fast-track construction.
Why use it?
One admixture delivers high-range water reduction and mix cohesion together, so highly fluid concrete stays homogeneous instead of bleeding, segregating or blocking the pump line.
How is it applied?
Dosed at 0.5–2.0% by weight of cementitious material into the mixing water — batch with roughly the last 15% of gauging water and mix 2–3 minutes; never onto dry cement.
About STP ShaliPlast PCE 300-VM
Self-compacting concrete lives or dies on a narrow balance: the mix must flow like a fluid yet hold its coarse aggregate in suspension. Most producers strike that balance with two chemicals — a PCE superplasticizer for flow and a separate viscosity-modifying admixture for cohesion — which doubles the batching steps and the chances of getting one of them wrong. ShaliPlast PCE 300-VM from STP Ltd folds both functions into a single light-brownish liquid, giving batching plants and site engineers one dosing decision instead of two.
The product conforms to IS 9103:1999 and ASTM C494 Type G as a high-range water-reducing and retarding admixture, and additionally complies with IS 2645:2003 as an integral waterproofing compound — a useful secondary credential when the pour doubles as a water-retaining element. It is chloride-free, compatible with all Portland cements including sulphate-resisting cement, and works alongside fly ash, GGBFS and microsilica blends common in Indian ready-mix practice. Space Arc Engineering supplies ShaliPlast PCE 300-VM in 225 kg barrels across Delhi NCR and pan-India, with technical support for trial mixes and dosage optimisation.
The technical insight
The PCE fraction works by adsorption and steric hindrance: comb-shaped polymer molecules anchor onto cement grains while their long side chains physically push neighbouring particles apart. That releases the water trapped between flocculated grains, so the mix flows dramatically better at a lower water-cement ratio. On its own, though, that extra fluidity is dangerous — a very flowable paste lets coarse aggregate sink and bleed water rise. The integrated VMA counters this by raising the plastic viscosity and thixotropic behaviour of the paste: the mix stays fluid while being pumped or placed, then stiffens at rest, holding aggregate in suspension through transport, pumping and placement. The Type G classification also means a controlled retarding action, which helps slump retention in Indian ambient temperatures — but it is the same mechanism that punishes overdosing with delayed set, which is why the 0.5–2.0% dosage window must be pinned down by site trials rather than assumed.
Where it is used
- Self-compacting concrete for rafts, columns, walls and beams with congested reinforcement
- Precast and prestressed elements where fast form stripping drives production cycle times
- Flowing and sprayed concrete applications
- Lightweight-aggregate concrete, where segregation risk is inherently high
- Lean concrete mixes that need workability at low cement contents
- Fast-track construction requiring high early strength development
- Architectural and fair-faced concrete where a blemish-free surface finish matters
- Long pump lines and high-lift pumping where reduced pump pressure is valuable
Key advantages
- Single-product SCC chemistry — high-range water reduction and viscosity modification in one admixture, with no separate VMA to batch or mis-dose
- Improves thixotropic behaviour, keeping the mix stable through transit, pumping and placement
- Controls bleeding and segregation even in highly fluid mixes, protecting dimensional stability and surface finish
- Powerful plasticizing action improves compaction and lowers pump pressure
- Promotes early strength gain, enabling faster stripping in precast and in-situ work
- Reduces permeability and shrinkage, and doubles as an integral waterproofing compound per IS 2645:2003
- Chloride-free — safe for reinforced and prestressed concrete
- Compatible with all Portland cements including SRC, and with PFA, GGBFS and microsilica
Limitations & considerations
- The 0.5–2.0% dosage window is wide; the working dose must be fixed by site trials with the actual cement and mix design — it cannot be assumed from the datasheet
- Overdosing delays concrete setting, an inherent trait of its ASTM C494 Type G retarding character
- Slump loss and setting times shift with concrete temperature — hot-weather performance needs trial validation before production pours
- Supplied only in 225 kg barrels, which suits RMC plants and large sites but not small repair jobs
- The admixture must never contact dry cement — it has to enter the mix through the gauging water
- SCC made with it exerts near-full hydrostatic pressure on formwork; walls and narrow sections need watertight, adequately designed forms
Selection & best practice
Charge all concrete materials into the mixer with about 85% of the mixing water and mix normally. Add ShaliPlast PCE 300-VM with the remaining water to reach the target consistency, then mix for a further 2–3 minutes — direct contact with dry cement must be avoided. Establish the dose (0.5–2.0% by weight of cementitious material) through trial mixes with the project cement, supplementary materials and target slump flow, and re-verify whenever the cement source changes. Treat formwork as an SCC-specific design item: forms for walls and narrow sections must be watertight and strong, because during the flowing period the concrete exerts higher pressure at the base of the form than conventional concrete; slab formwork is unchanged. Wear gloves and eye protection when handling, store barrels in a cool, dry, shaded place away from heat, and use stock within 12 months of manufacture in unopened condition.
Specifications
| Chemistry | Third-generation polycarboxylate ether (PCE) with integral VMA |
| Form / Colour | Liquid, light brownish |
| Specific gravity at 30°C | 1.06 ± 0.04 |
| pH | > 6 |
| Chloride content | Nil |
| Dosage | 0.5–2.0% by weight of cementitious material (finalise by site trial) |
| Standards | IS 9103:1999; ASTM C494 Type G; IS 2645:2003 (integral waterproofing) |
| Packing | 225 kg barrel |
| Shelf life | 12 months in original unopened packing |
Industry use cases
Metro & Infrastructure
SCC for pile caps, pier caps and diaphragm walls where reinforcement congestion makes vibration impractical and honeycombing is the chief defect risk.
High-Rise & RMC
Pumped self-compacting mixes for tall pours — the VMA keeps the mix cohesive over long pump lines while the PCE cuts pump pressure.
Precast Plants
High early strength and vibration-free casting shorten demoulding cycles and improve surface finish on repetitive precast elements.
Architectural Concrete
Fair-faced walls and exposed structural elements where bleed marks, sand streaking and blowholes would be unacceptable.
Water-Retaining Structures
Tanks and basements benefit from the reduced permeability and the admixture’s IS 2645:2003 compliance as an integral waterproofing compound.
Frequently asked questions
What dosage should we start trial mixes at?
How is PCE 300-VM different from a standard PCE superplasticizer?
Which standards does it comply with?
Is it compatible with fly ash, GGBS and microsilica mixes?
What happens if the admixture is overdosed?
What pack size does it come in, and how long does it keep?
How we position STP ShaliPlast PCE 300-VM
Within the STP admixture family, ShaliPlast PCE 300-VM is the SCC specialist: if your pours are conventional pumped concrete that will still be vibrated, the standard ShaliPlast PCE grades without the viscosity modifier are the more economical fit, and SNF-based ShaliPlast grades remain adequate for ordinary structural mixes. Space Arc also supplies the Fosroc Auramix PCE range for projects standardised on Fosroc specifications, and Sika ViscoCrete technology where a consultant has named it. Talk to our technical team with your mix design and target slump flow — we will recommend the grade and run comparative site trials rather than defaulting to the most expensive option.
Fosroc Auramix 500 — Specifiers already standardised on Fosroc admixture systems typically choose Auramix 500 for SCC and high-grade pumped concrete, though unlike PCE 300-VM it may need a separate viscosity-modifying admixture where extra mix cohesion is critical.
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