Sika SikaGrout-300 PT
Sand-free, zero-bleed cementitious grout that flows into post-tensioning ducts and tight voids where sanded grouts simply cannot reach.
What is it?
A high-performance, sand-free, cementitious injection grout from Sika with a two-stage shrinkage-compensating mechanism, designed to fill post-tensioning ducts and tight clearances.
Where is it used?
Post-tensioning cable ducts, anchor pockets, and any narrow injection gap in bridges, flyovers and prestressed building frames where a sanded grout would jam or leave voids.
Why use it?
It stays fully fluid, bleeds essentially nothing, and expands slightly to eliminate voids around prestressing steel, protecting the strand from corrosion and locking in load transfer.
How is it applied?
Add clean water (5.45-6.15 L per 22.7 kg bag), shear-mix for about 3-6 minutes to a homogeneous fluid, then pump through a colloidal or high-shear mixer into the duct.
About Sika SikaGrout-300 PT
SikaGrout-300 PT sits in a narrow but critical corner of the grouting world: places where an ordinary sanded, non-shrink grout is simply too coarse to help. The sand that gives conventional grouts their body is exactly what stops them flowing into a congested post-tensioning duct or a hairline anchor void. Sika’s answer is to remove the sand entirely and rebuild the performance chemically. The result is a smooth, fluid, cementitious grout that moves like a liquid, carries no aggregate to block the path, and still develops the strength and stability a structural grout demands. For engineers dealing with prestressed bridge decks, flyover girders or PT floor slabs, it is the material that gets grout to the last few millimetres around the strand.
What makes it a specifier’s grout rather than a general-purpose one is its behaviour in the plastic and hardened states. It is silica-fume enhanced for low permeability, contains no chlorides and no aluminium powder, and uses a blend of shrinkage-reducing and plasticising agents to compensate for shrinkage twice over, first while it is still plastic, then again as it hardens. That combination means the grout does not settle, does not bleed a water layer to the top of the duct, and does not pull away from the steel it is meant to protect. Space Arc Engineering supplies SikaGrout-300 PT to contractors and consultants across Delhi NCR and pan-India, with the technical backup to match it to the right duct geometry, pump and site conditions.
The technical insight
The whole point of a PT grout is corrosion protection through complete, void-free encasement of the prestressing strand, and voids are created by two enemies: bleed and shrinkage. Ordinary grouts bleed because free water migrates upward and collects at high points and under the strand, leaving channels where moisture and chlorides later attack the steel. SikaGrout-300 PT is engineered to zero-bleed even at high flow, so no water separates out during the hours it takes to pump and set a long duct. The second enemy, shrinkage, is countered by a two-stage compensating mechanism rather than a single gas-expansion trick: controlled positive volume change of 0 to +2.0% at 3 hours (ASTM C940) handles the plastic phase, and volume change stays between 0.0 and +0.3% out to 28 days (ASTM C1090) in the hardened phase. Crucially, that expansion is achieved without aluminium powder, so no hydrogen, carbon dioxide or oxygen gas is generated inside the duct. The sand-free, silica-fume matrix then delivers low permeability (electrical resistivity keeps water/binder under 0.40, ASTM C1202) so the hardened grout itself resists chloride ingress rather than merely surviving it.
Where it is used
- Injecting bonded post-tensioning cable ducts in bridge decks, flyover girders and prestressed beams
- Filling anchor pockets and end-anchorage voids after stressing
- Grouting congested or tight-clearance ducts where sanded grouts will not flow
- Remedial grouting and re-grouting of partially filled or voided existing PT ducts
- Vacuum grouting of small voids using a high-speed drill and Jiffy paddle
- Corrosion-protection encasement of prestressing strand in aggressive or coastal exposure
- Filling narrow structural gaps and voids where a fluid, aggregate-free grout is required
- Injection anchoring in confined clearances too small for a sanded repair mortar
Key advantages
- Sand-free formulation flows into ducts and voids that sanded grouts physically cannot fill
- Zero bleed even at high flow, so no water channels form around the strand
- Two-stage shrinkage compensation covers both the plastic and hardened states
- Generates no hydrogen, CO2 or oxygen gas as it contains no aluminium powder
- Silica-fume enhanced for low permeability and improved chloride resistance
- Contains no chlorides and is non-metallic, so it will not stain, rust or corrode
- Excellent pumpability with no segregation and no build-up on the equipment hopper
- Single-bag, just-add-water product that develops high strength (77 MPa at 28 days)
Limitations & considerations
- Minimum ambient and substrate temperature is 5 C and rising at application, unless a Sika accelerator is used
- Application thickness is confined to 3 mm minimum and 25 mm maximum
- Not for use as a patching or overlay mortar, or in unconfined areas
- As with all cement grouts, avoid contact with aluminium; insulate aluminium with an epoxy coating to prevent an adverse reaction
- Being aggregate-free, it is a specialist injection grout, not a general-purpose bedding or repair grout
- Accurate water dosing is essential, as excess water can trigger exudation or bleeding
Selection & best practice
Start every project with a site trial batch, because flow is sensitive to water quantity, mixing time, batch size and temperature. Prepare the substrate first: remove dirt, oil and grease mechanically, de-grease anchor bolts with a compatible solvent, and bring concrete to a saturated surface-dry condition. Always begin at the low end of the water range, 5.45 L per 22.7 kg bag, and add water gradually only if the required flow is not met, never exceeding 6.15 L per bag. Use a colloidal or high-shear mixer at around 1800 rpm and mix for roughly three minutes to a homogeneous consistency, extending up to six minutes on larger batches; for small vacuum-grouting quantities, use a high-speed drill and Jiffy paddle for a minimum of six minutes. Keep water, material and ambient temperatures as close to 21 C as possible, using colder water when it is hot and warmer water when it is cold. Meter water accurately batch to batch and keep the material agitated in the holding hopper to preserve flow right up to injection.
Specifications
| Type | Fluid, non-shrink, sand-free cementitious grout (two-stage shrinkage compensation) |
| Compressive strength (ASTM C942) | 25 MPa at 1 day, 34 MPa at 3 days, 48 MPa at 7 days, 77 MPa at 28 days |
| Bleed / expansion | Zero bleed; volume change 0 to +2.0% at 3 hours (ASTM C940), 0.0 to +0.3% at 28 days (ASTM C1090) |
| Fluidity | 7-20 s immediately and 30 min after mixing (ASTM C939 modified) |
| Water content | 5.45-6.15 L (11.5-13 pints) per 22.7 kg bag; W/B less than 0.40 |
| Wet density | Approx. 2000 kg/m3 (ASTM C138) |
| Total chloride ion content | Less than 0.04% by weight of cementitious material (ASTM C1152) |
| Setting time | Between 3 and 12 hours (ASTM C953) |
| Packaging / yield | 22.7 kg multi-wall bag (56 bags/pallet); approx. 14 L of fluid grout per bag |
| Standards | Meets CRD C 621 and ASTM C1107 (Grade C) |
Industry use cases
Bridges & Flyovers
Grouting bonded post-tensioning ducts in prestressed bridge decks and girders, where zero bleed and low permeability protect the strand against de-icing salts and coastal chlorides.
Infrastructure & Metro
Filling PT ducts and anchor pockets in viaduct segments and metro guideways, where fully fluid, aggregate-free grout reaches congested tendon paths.
High-Rise & Commercial
Injecting post-tensioned floor slabs and transfer beams in commercial towers, delivering high early strength for faster stressing and load transfer.
Repair & Rehabilitation
Remedial re-grouting of existing PT ducts found to be voided or partially filled during inspection, restoring corrosion protection to ageing prestressed structures.
Industrial Structures
Tight-clearance injection anchoring and void filling in confined gaps where a sanded grout would bridge and leave defects.
Frequently asked questions
Why is SikaGrout-300 PT sand-free, and when does that matter?
How much water do I add per bag, and why does it matter so much?
Does it need aluminium powder or a gas expander to compensate shrinkage?
What compressive strength can I expect?
What are the thickness and temperature limits?
What mixer and pump should I use on site?
How we position Sika SikaGrout-300 PT
SikaGrout-300 PT is Sika’s specialist for the tight, sand-free end of grouting; when a job needs a sanded structural or machine-base grout instead, look to SikaGrout-212 or the SikaGrout GP range from the same family. For crack injection and anchoring on the epoxy side, Sikadur epoxies (such as Sikadur-32 for bonding, or Sikadur-42 anchoring grout) complement it, and Sika FerroGard-901 can be dosed into the mix water for added corrosion protection. Across our other brands, contractors standardised on Fosroc will find a genuine like-for-like in Conbextra Cable Grout HS for the same PT-duct duty; for site-batched cementitious grouts, Fosroc Cebex 100 provides the plasticising-plus-expansion admixture route. Talk to Space Arc if you need help matching duct geometry, pump and exposure class to the right grout.
Fosroc Conbextra Cable Grout HS — A specifier standardised on Fosroc for prestressed work may prefer this CARES-approved, single-component shrinkage-compensated cable-duct grout as a direct like-for-like for the same post-tensioning duty.
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