Master Builders Solutions MasterFlow 928T
High-strength, non-shrink cementitious precision grout, tropicalised so workability survives Indian site temperatures — for turbine baseplates, heavy machinery, anchor bolts and bridge bearings. ASTM C1107 Grade C.
What is it?
A single-component, high-strength, non-shrink cementitious precision grout from Master Builders Solutions — only clean measured water is added on site.
Where is it used?
Under turbine and generator baseplates, presses, milling machines and crane rails; in anchor bolt pockets, precast connections and bridge bearing beds.
Why use it?
Dual-stage controlled expansion keeps full bearing contact under plates, it reaches about 20 N/mm² in 24 hours even at fluid flow, and the tropicalised formulation holds workability in hot weather.
How is it applied?
Mix 25 kg with 4.5–5.0 litres of water in a mechanical mixer, pour continuously from one side under a 15 cm hydrostatic head into gaps of 10–80 mm, then moist-cure immediately.
About Master Builders Solutions MasterFlow 928T
MasterFlow 928T is the tropicalised edition of one of the most widely specified precision grouts in the world, from the Master Builders Solutions stable (formerly BASF Construction Chemicals). The “T” changes nothing in the base formulation — a Portland-cement binder with graded natural aggregate and micro-silica — it simply extends workability retention so the grout stays placeable through the ambient temperatures common on Indian sites. Supplied as a ready-to-mix powder in 25 kg moisture-resistant bags, it needs only measured site water to produce a non-shrink grout that can be placed at any consistency from fluid to damp-pack.
For consultants, the approval trail is straightforward: compliance with ASTM C1107 Grade C and CRD-C 621, no visible bleed water under ASTM C232, and typical fluid-consistency strengths of 20 N/mm² within a day rising to 60 N/mm² at 28 days. Space Arc Engineering stocks and supplies MasterFlow 928T across Delhi NCR and pan-India, and our applicator teams have placed it under everything from DG sets to bridge bearings — so method-statement support comes with the material.
The technical insight
A precision grout earns its keep in the first 24 hours, and that is where 928T’s chemistry is concentrated. A controlled expansion system acts in two stages — in the plastic state, offsetting settlement before set, and again in the early hardened state — with the action largely complete within the first 12 hours of curing. Net expansion stays within tight limits (about 0.05% under ASTM C878, and 0.3% by the Corps of Engineers method against a 0.4% ceiling), so the grout locks against the baseplate underside without over-expanding. Micro-silica refines the pore structure so effectively that water does not penetrate specimens even at 20 atmospheres — a computed permeability below 1×10⁻¹² cm/sec — while pull-off bond to concrete runs 2–4 MPa. Fatigue testing of 2 million load cycles between 20 and 50 N/mm² left specimens undamaged, which is why this grout is trusted under rotating and reciprocating machinery.
Where it is used
- Precision grouting under gas and steam turbine and generator baseplates
- Bedding heavy presses, milling machines and machine-tool foundations
- Crane rail and gantry rail grouting in plants and ports
- Anchor bolt and holding-down bolt fixing in pockets and sleeves
- Bedding of bridge bearings on piers and abutments
- Grouting joints and connections between precast elements
- Under-plate grouting of structural steel columns and stanchion bases
- Any 10–80 mm gap where certified non-shrink performance is specified
Key advantages
- Certified non-shrink performance to ASTM C1107 Grade C and CRD-C 621 — easy consultant approval
- Tropicalised formulation retains workability even at high ambient temperatures
- One product covers every consistency from fluid (20–30 s flow cone) to damp-pack
- Early strength of about 20 N/mm² at 1 day, even when mixed fluid
- High bond to steel and concrete — typically 2–4 MPa in pull-off testing
- Effectively impermeable micro-silica matrix protects embedded bolts from moisture
- Proven fatigue and impact resistance under dynamic machinery loading
- No bleed water at recommended dosing (ASTM C232), so no weak top layer under plates
Limitations & considerations
- Placement band is 10 mm to 80 mm per pour — deeper gaps call for MasterFlow 980T, not site improvisation
- Grout and all contact surfaces must be held between 10°C and 35°C during placement
- Must never be retempered with extra water once mixed; stiffened material has to be discarded
- A mechanically powered grout mixer is essential — hand mixing will not develop the stated properties
- Published fluid-consistency strengths are lower than the trowelable-mix figures some rival datasheets quote, so compare like for like
- Where rapid set or resistance to chemical spillage is needed, an epoxy grout is the better choice
Selection & best practice
Success with 928T is mostly preparation. Scabble the foundation to expose aggregate — avoid bush hammers, which crush aggregate but leave it in place — and remove all oil, laitance and curing compound. Pre-soak the pour area for 24 hours; surfaces should be damp with no standing water, and bolt pockets blown dry with oil-free compressed air. Charge the measured water into a damp mechanical mixer first (4.5–5.0 litres per 25 kg for fluid consistency), add powder gradually and mix a full five minutes to a lump-free grout. Pour continuously from one side only, maintaining a hydrostatic head of at least 15 cm; allow 10 cm formwork clearance on the pouring side and 5–10 cm opposite, and use steel strapping with a gentle sawing action to move grout under wide plates. Do not vibrate. Cover exposed grout with damp hessian at once, follow with a curing membrane, shade the works in hot weather, and shut down adjacent machinery until the grout hardens.
Specifications
| Compressive strength (fluid, 25°C, 100 mm cubes) | 20 / 35 / 45 / 60 N/mm² at 1 / 3 / 7 / 28 days |
| Flexural strength (40×40×160 mm prisms) | 4.0–9.0 N/mm² from 1 to 28 days |
| Flow cone (ASTM C939) | 20–30 seconds at fluid consistency |
| Mixing water | 4.5–5.0 litres per 25 kg bag (fluid) |
| Wet density | Approx. 2,220 kg/m³ |
| Yield | 13.8 litres per 25 kg bag at 5 L water; approx. 73 bags per m³ |
| Static modulus of elasticity | Approx. 28,000 N/mm² at 28 days |
| Application thickness | 10 mm minimum to 80 mm maximum per pour |
| Standards & packaging | ASTM C1107 Grade C, CRD-C 621; 25 kg bags, ~12-month shelf life |
Industry use cases
Power Generation
Grouting gas and steam turbine, generator and DG-set baseplates, where ~20 N/mm² day-one strength lets alignment and holding-down loads go on quickly.
Steel & Heavy Manufacturing
Bedding presses, rolling-mill auxiliaries and machine tools — 2-million-cycle fatigue endurance suits repetitive dynamic loading.
Bridges & Metro Infrastructure
Bearing bedding on piers, pedestals and abutments, where zero shrinkage gap under the bearing plate is non-negotiable.
Ports & Material Handling
Gantry and crane rail grouting plus anchor bolt fixing in impact-prone, weather-exposed marine environments.
Precast Construction
Column-to-pocket joints and structural connections between precast elements, placed fluid for full void filling.
Frequently asked questions
What does the T in MasterFlow 928T stand for?
How much water goes into each bag, and what is the yield?
What gap thickness can it be poured in?
How soon can equipment load be applied?
Which standards does it comply with for consultant approval?
Can MasterFlow 928T be pumped?
How we position Master Builders Solutions MasterFlow 928T
Within the Master Builders Solutions grout family, MasterFlow 928T is the general-purpose precision workhorse. Step up to MasterFlow 980T when pour depths exceed 80 mm, and to a MasterFlow epoxy grout where very rapid set or chemical-spillage resistance is required; for severe impact and repetitive dynamic loading beyond what cementitious grout should carry, the metallic-aggregate MasterFlow 885 takes over. Pair every pour with a MasterKure curing membrane for reliable early curing. For projects standardised on other systems, Space Arc also supplies Fosroc’s Conbextra non-shrink grout range as a comparable alternative — talk to us and we will match the grout to your clearance, loading and approval requirements.
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