STP ShaliPlast LT
Chloride-free cold weather concreting admixture that keeps cement hydration alive down to -12°C — built for Himalayan infrastructure, winter precast runs and frost-prone pours across North India.
What is it?
A brown liquid antifreeze-cum-plasticising admixture from STP Limited that lets you produce quality concrete at ambient temperatures as low as -12°C, conforming to IS 9103:1999 and ASTM C494 Type G.
Where is it used?
Winter concreting wherever daytime or overnight frost is expected — high-altitude roads, bridges and tunnels, precast yards, cold-store construction and general RCC work in North and Northeast India.
Why use it?
It sustains hydration heat and cuts freezable mix water, so fresh concrete reaches a frost-safe strength before ice can wreck the matrix — and being chloride free, it poses no corrosion risk to rebar.
How is it applied?
Dosed at 2.0-2.5% by weight of cement into the mixing water as the last component added to the mix; exact dosage is fixed through site trials with your cement and aggregates.
About STP ShaliPlast LT
Fresh concrete and frost are natural enemies. Below about 5°C hydration slows to a crawl, and if pore water freezes before the concrete has gained meaningful strength, expanding ice lenses tear the young matrix apart — the damage is permanent and no amount of later curing repairs it. ShaliPlast LT from STP Limited is formulated for exactly this window. It is a single-pack brown liquid admixture that allows mixing, placing and curing of quality concrete at moderately low ambient temperatures, down to -12°C, without resorting to chloride-based accelerators that endanger reinforcement.
For Indian projects the relevance is obvious: December-to-February pours in Delhi NCR, Punjab and UP routinely see overnight frost, while work in Ladakh, Himachal, Uttarakhand, Kashmir and Arunachal faces sub-zero conditions for months. ShaliPlast LT keeps these programmes moving instead of parking them for the season. Space Arc Engineering supplies the product pan-India as an authorised STP distributor and supports dosage trials, mix-design coordination and cold-weather pour planning through its applicator teams.
The technical insight
ShaliPlast LT attacks the freezing problem from two directions. First, its plasticising action (classified under ASTM C494 Type G) lets you cut mixing water without losing workability — and less free water in the mix means less water available to freeze, plus a denser, stronger paste. Second, the admixture promotes hydration at low temperature and increases the heat the reaction releases, so the concrete generates its own warmth faster than the cold environment can drain it. The practical goal is to carry the pour past roughly 5 MPa compressive strength — the threshold (per DIN 1045) below which a freeze event causes irreversible damage — before the first hard frost bites. That is why the TDS pairs the admixture with insulation and warm ingredients: the chemistry buys you reaction speed and a lower freezable-water content, while good site practice conserves the heat being produced.
Where it is used
- Winter RCC pours in North Indian plains where slight daytime frost or overnight frost is expected
- High-altitude road, bridge and tunnel concreting in Ladakh, Himachal, Uttarakhand, Kashmir and the Northeast
- Precast yards maintaining production schedules through the winter months
- Ready-mix supply where transit and placing extend into early-morning or late-evening frost hours
- Concreting for cold-storage and food-processing facilities built or extended in low-temperature conditions
- Hydropower and dam-appurtenant works in cold river valleys
- Foundations, footings and machine bases that cannot wait for the season to turn
- Structural repair pours in cold weather where heated enclosures are impractical
Key advantages
- Enables concreting at ambient temperatures down to -12°C instead of a seasonal shutdown
- Chloride free — does not attack reinforcement, so it is safe for RCC and prestressed elements
- Improves workability without extra water, or cuts water content at equal workability
- Increases hydration heat, helping fresh concrete outrun heat loss to the cold environment
- Improves strengths alongside its frost-resistance function
- Conforms to IS 9103:1999 and ASTM C494 Type G — straightforward to justify in specifications
- Simple liquid dosing into the mixing water; no batching-plant modification needed
- Compatible with other STP admixtures in the same mix when dosed separately and verified by trial mixes
Limitations & considerations
- It is not a substitute for cold-weather practice — insulation, warm mixing water, heated aggregates and surface protection are still required
- Cement, aggregates and water must all be above 0°C at mixing; the admixture cannot rescue frozen ingredients
- Concrete remains freeze-vulnerable until it reaches about 5 MPa compressive strength, so early protection is critical
- Rated for moderately low temperatures to about -12°C; more severe cold calls for heated enclosures and specialist methods
- Dosage of 2.0-2.5% by cement weight is high compared with routine plasticisers, and slump loss and setting behaviour vary with cement source — site trials are mandatory, not optional
- Supplied only in 225 kg barrels, which suits project-scale procurement but not very small jobs
Selection & best practice
Fix the dosage by trial mix with your actual cement, aggregates and target ambient temperature — start within the 2.0-2.5% by-weight-of-cement band. Add ShaliPlast LT to the mixing water and introduce it as the last component; never dose it onto dry cement, and never premix it with other admixtures in the same container. Keep the water-cement ratio as low as the plasticising effect allows and resist adding water for flow. Schedule pours for morning hours so the concrete gains strength through the warmer part of the day, and cover fresh surfaces with plastic sheeting or insulation to trap hydration heat while it sets and hardens. Cure properly, and keep protection in place until the concrete has passed the 5 MPa frost-safety threshold. Store barrels shaded, sealed and away from heat between 5 and 38°C.
Specifications
| Form / colour | Brown liquid |
| Density (at 27°C, 55% RH) | 1.24 ± 0.03 g/cc |
| pH | 3 – 4 |
| Recommended dosage | 2.0 – 2.5% by weight of cement (finalise by site trial) |
| Working temperature | Concreting at ambient temperatures down to -12°C |
| Chloride content | Chloride free — does not attack reinforcement |
| Standards | IS 9103:1999; ASTM C494 Type G |
| Packaging | 225 kg sealed barrel |
| Shelf life | 12 months unopened, stored at 5 – 38°C away from heat and sunlight |
Industry use cases
Himalayan Infrastructure
Border roads, tunnels and bridge substructures in Ladakh, Himachal and Arunachal keep winter concreting windows open, reaching frost-safe strength before overnight temperatures plunge.
Precast & RMC
Precast yards and ready-mix plants in North India hold winter production schedules and delivery commitments without heated curing chambers for every element.
Cold Storage & Food Processing
Slabs, plinths and structural frames for cold-chain facilities are often cast in already-cold environments where conventional mixes would stall.
Hydropower
Powerhouse, intake and appurtenant structures in cold river valleys of Uttarakhand and the Northeast are concreted through late-autumn and winter shifts.
Defence & Strategic Works
High-altitude helipads, shelters and hard standings are built inside short seasonal windows where every workable day counts.
Frequently asked questions
What is the lowest temperature at which I can pour concrete with ShaliPlast LT?
What is the dosage, and how do I finalise it?
Is it safe for reinforced concrete?
Can I use it together with a superplasticiser or air-entrainer?
Does it replace warm water, heated aggregates and insulation?
What pack size does it come in, and how long does it keep?
How we position STP ShaliPlast LT
ShaliPlast LT is the cold-weather specialist within STP’s admixture family, and it rarely works alone. Pair it with STP ShaliPlast AE air-entraining additive when the hardened structure will face repeated freeze-thaw cycles in service, or with the ShaliPlast PCE range of superplasticisers when a low water-cement ratio and high workability must coexist — dosed separately and proven in trial mixes. For jobs that simply need faster setting and early strength in cool (rather than sub-zero) weather, STP ShaliPlast FS2 plasticising accelerator is often the more economical pick. From our Fosroc line, Conplast NC offers a chloride-free formate-based accelerator that many consultants specify for winter precast and repair work in milder cold. Space Arc Engineering stocks both brands and can run comparative dosage trials so your mix, not a brochure, makes the final call.
Fosroc Conplast NC — Specifiers working in milder cold — where the goal is faster setting and early strength rather than true sub-zero antifreeze protection — often choose Conplast NC, a chloride-free formate accelerator dosed at 2.0-3.0 litres per 100 kg of cement.
Related Concrete Admixtures products
Source STP ShaliPlast LT for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.