STP ShaliPlast PCE 400 H
Third-generation polycarboxylic ether superplasticiser with built-in set retardation — ASTM C494 Type G performance for ready-mix, self-compacting and fast-track concrete that must hold its slump through the haul.
What is it?
A third-generation polycarboxylic ether (PCE) superplasticiser with an integrated retarding action, supplied by STP Limited as a light-brownish, chloride-free liquid admixture.
Where is it used?
Ready-mix and self-compacting concrete, high-workability pours, fast-track construction and in-situ work where formwork must be stripped early despite long delivery hauls.
Why use it?
One Type G admixture handles both jobs — high-range water reduction for dense, high-strength concrete, and controlled retardation so workability survives transit and hot weather.
How is it applied?
Dosed at 0.5–1.0% by weight of cementitious material into the gauging water or directly into the mixer — never onto dry cement — with the final dosage fixed by site trials.
About STP ShaliPlast PCE 400 H
ShaliPlast PCE 400 H is STP Limited’s third-generation polycarboxylic ether superplasticiser formulated with a built-in retarding component, for use in concrete, mortar and plasters. It conforms to IS 9103-1999 and ASTM C494 Type G — the high-range water-reducing and retarding class that engineers specify when concrete has to stay workable through a long haul yet still gain strength quickly once placed. The liquid is light brownish with a specific gravity of 1.10 ± 0.04 and carries nil chloride, so it goes into reinforced and prestressed work without corrosion concern.
In Indian site conditions the product earns its keep at the batching plant. A transit mixer crossing NCR traffic in May can lose workability faster than any mix design allows for; the retarder in PCE 400 H holds early hydration back so slump survives the journey, while the PCE backbone delivers the water reduction needed for dense, low-permeability, high-strength concrete. Space Arc Engineering supplies it in 225 kg barrels from Delhi NCR with Pan-India dispatch, alongside the rest of the ShaliPlast admixture range, and supports plant-level dosage trials before you commit a mix design.
The technical insight
PCE chemistry disperses cement differently from the older SNF and lignosulphonate generations. The polycarboxylic ether molecule is a comb polymer: a charged backbone grips the cement grain while long side chains physically push neighbouring grains apart by steric hindrance, not surface charge alone. That separation releases the water trapped inside flocculated clusters, which is why a PCE achieves far greater water reduction at lower dosage than first- and second-generation admixtures. In the 400 H, a retarding component extends the dormant period of early hydration, so the dispersion — and therefore the slump — persists longer. Because retardation only postpones hydration rather than suppressing it, strength development after setting remains strong, which is what makes economical stripping times possible. One caution straight from STP’s data sheet: higher concrete temperature increases slump loss and shortens the initial set, so dosage calibrated in winter cannot simply be carried into summer.
Where it is used
- Ready-mix concrete requiring slump retention over long transit and pumping distances
- Self-compacting concrete for congested reinforcement and complex formwork
- High-workability and flowing concrete for rafts, columns and pump placements
- Fast-track construction where early strength shortens formwork cycles
- In-situ concrete requiring fast stripping on repetitive floor cycles
- Hot-weather and staged pours where set control helps avoid cold joints
- Reinforced and prestressed concrete, the formulation being fully chloride-free
Key advantages
- Dual Type G action — high-range water reduction and controlled retardation from a single admixture
- Pronounced early strength development, giving economical stripping times for precast and in-situ concrete
- Powerful water reduction producing dense, high-strength concrete with reduced water permeability
- Higher mix cohesion that cuts segregation and bleeding in flowing concrete
- Improved shrinkage and creep behaviour versus higher-water conventional mixes
- Nil chloride content — safe for reinforced and prestressed steel
- Compatible with all Portland cements including SRC, and with PFA, GGBFS and micro silica blends
Limitations & considerations
- Overdosing delays concrete setting — dosage must be fixed by site trials, never assumed from the data sheet
- Slump-loss and setting behaviour shift with concrete temperature, so hot-weather mixes need fresh calibration
- Must never contact dry cement; dispensing discipline at the plant is essential
- The retarding action is unwanted where rapid set matters — thin sections and cool-weather pours suit the plain PCE 400 better
- Flowing concrete exerts higher pressure at the base of wall forms, demanding watertight, well-braced formwork
- Supplied only in 225 kg barrels, which suits plants but not small trial users
Selection & best practice
Charge aggregates and cement into the mixer with about 85% of the mixing water and blend as usual. Add ShaliPlast PCE 400 H with the remaining water to reach target slump, then mix a further 3–4 minutes — delayed addition lets the PCE molecules disperse cement efficiently instead of being consumed by early hydration products. Never let the admixture touch dry cement. Start trials at 0.5–1.0% by weight of cementitious material, moving to 1–2% only for self-compacting or very low water-cement mixes, and re-trial whenever the cement source, supplementary materials or ambient temperature changes. For walls and narrow sections, make forms watertight and well braced: during the flowing period the concrete pushes harder at the form base than a conventional mix. Store barrels under shed in a cool, dry place away from heat; shelf life is 12 months unopened.
Specifications
| Form / colour | Light brownish liquid |
| Chemical base | Third-generation polycarboxylic ether (PCE) with retarder |
| Specific gravity | 1.10 ± 0.04 |
| pH | 6 – 8 |
| Chloride content | Nil |
| Dosage | 0.5 – 1.0% by weight of cementitious material (1 – 2% for SCC / very low w/c mixes) |
| Standards compliance | IS 9103-1999; ASTM C494 Type G |
| Packing | 225 kg barrel |
| Shelf life | 12 months in original unopened packing |
Industry use cases
Ready-Mix Concrete Plants
RMC producers dosing PCE 400 H at the plant deliver concrete that still meets specified slump after long urban hauls, removing the temptation to add water at site and wreck the design water-cement ratio.
Metro & Infrastructure
Mass rafts, piers and staged structural pours benefit from controlled retardation between truckloads, reducing cold-joint risk while the high-range water reduction keeps permeability low for durability-critical elements.
High-Rise Construction
Pumped concrete for tall RCC frames needs flowability at the nozzle and cohesion in congested columns; the PCE backbone provides both, and early strength keeps floor-cycle formwork on schedule.
Precast Yards
The pronounced early strength gain after set shortens demoulding times, letting beds turn over faster while the chloride-free formulation protects prestressing strand.
Industrial & Institutional Projects
Self-compacting mixes for machine foundations and heavily reinforced sections place without vibration gaps, with site trials establishing the 1–2% SCC dosage against the project cement.
Frequently asked questions
How is ShaliPlast PCE 400 H different from ShaliPlast PCE 400?
What dosage should we start trials at?
Will the retardation reduce early strength?
Is it safe for prestressed and reinforced concrete?
Does it work with fly ash, GGBS or micro silica blended cements?
What pack size does it come in, and how should it be stored?
How we position STP ShaliPlast PCE 400 H
Within STP’s admixture family, PCE 400 H is the retarded partner to ShaliPlast PCE 400 — pick the plain 400 when hauls are short and a faster set is welcome, and look at ShaliPlast PCE 300-VM when self-compacting mixes need viscosity modification against segregation. For projects specified around Fosroc systems, the Auramix PCE range covers the same ready-mix territory, while Conplast SP430 remains the economical SNF option for mid-grade concrete. Space Arc stocks all of these and can run comparative trial dosages against your project cement before a plant standardises on one system.
Fosroc Auramix 400 — Specifiers standardised on Fosroc systems get comparable PCE-based water reduction and slump retention from Auramix 400, a natural pick for ready-mix producers who want one approved admixture vendor across all their projects.
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