About Sika Plastocrete Plus

Sika Plastocrete Plus is one of the most widely specified integral waterproofing admixtures on Indian sites, and its appeal comes from doing two jobs at once. Chemically it is a modified ligno-sulphonate supplied as a dark-brown liquid of roughly 1.08 density, and it functions simultaneously as a water-reducing plasticiser and a permeability-reducing agent. Rather than sitting on the surface like a membrane, it works within the concrete itself, so the waterproofing is built into the structure and cannot be punctured, peeled or worn away over the life of the element. It conforms to IS 2645 for integral waterproofing compounds and IS 9103 for concrete admixtures, which keeps it acceptable on Government, PWD and institutional specifications across the country.

For an engineer or contractor the practical value is control over the water-cement ratio. Because the admixture improves flow, the same slump can be achieved with less mixing water, and a lower water content is the single biggest lever for a dense, low-permeability, low-shrinkage matrix. It is chloride-free, so there is no risk of promoting reinforcement corrosion in RCC. Space Arc Engineering supplies Plastocrete Plus as an authorised distributor and applicator across Delhi NCR and Pan-India, in pack sizes from 20 kg drums up to 200-230 kg containers, with technical support on dosage trials and mix design where a project demands it.

The technical insight

The waterproofing mechanism is about capillaries, not coatings. Fresh concrete carries far more water than the cement needs to hydrate; that surplus bleeds and evaporates, leaving a network of fine capillary pores through which water later travels. Plastocrete Plus attacks this on two fronts. As a ligno-sulphonate plasticiser it disperses cement particles, letting the same workability be reached at a lower water content, which directly shrinks the capillary volume and refines the pore structure. At the same time it densifies the paste and reduces the interconnected voids that allow water to migrate, so the hardened concrete resists both hydrostatic pressure and moisture ingress. A denser matrix with fewer, finer pores also shrinks less on drying, meaning fewer of the micro-cracks that would otherwise become leakage paths. Because the effect is chemical and distributed through the whole mix, it protects the full section rather than a single face.

Where it is used

• Watertight roof slabs, terraces and chajjas cast in situ
• Basement rafts, retaining walls and other below-grade RCC
• Water-retaining structures such as tanks, sumps, reservoirs and STP/ETP chambers
• Internal and external cement plaster where damp resistance is required
• Concrete for repair, renovation and re-plastering work
• Foundation and grade slabs exposed to ground moisture
• Lift pits and service ducts subject to water ingress
• General watertight concrete where a lower water-cement ratio is targeted

Key advantages

• Dual action: waterproofs and plasticises from a single admixture
• Reduces permeability by densifying the concrete matrix
• Allows a lower water-cement ratio for the same workability
• Reduces drying shrinkage and the associated cracking
• Chloride-free, so it will not promote reinforcement corrosion
• Improves compaction and gives a superior surface finish
• Conforms to IS 2645 and IS 9103 for specification compliance
• Easy to use: added at the mixer with no special equipment

Limitations & considerations

• Integral only; it will not bridge live cracks, honeycombing or bad construction joints, which still need a repair or membrane system
• Effective only with sound mix design, correct placing, compaction and curing; poor workmanship overrides any admixture
• Optimum dosage must be confirmed by site trials, as cement, aggregates and ambient conditions vary
• Overdosing beyond the recommended range can retard set or affect early strength
• Not a substitute for a positive-side membrane on structures under high or continuous hydrostatic head
• Being a liquid, it must be stored between +10 C and +40 C, away from sunlight and frost, and used within its 12-month shelf life

Selection & best practice

Specifications

Industry use cases

How we position Sika Plastocrete Plus

Within the Sika range, Plastocrete Plus is the everyday liquid integral waterproofer; where a project calls for a stronger plasticising effect or higher water reduction, step up to Sika Plastocrete Super, and for crystalline or cementitious surface waterproofing use a Sika membrane or slurry system on the positive face. Against our other brands, the closest equivalents are Dr. Fixit LW+ / Pidiproof LW+ and MC-Bauchemie’s integral admixtures; the choice usually comes down to approved-brand lists and site preference rather than a large performance gap. Space Arc supplies all of these, so specifiers can be matched to whatever their tender permits.

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