Master Builders Solutions MasterFlow 870
Cementitious high-strength non-shrink precision grout from Master Builders Solutions — 30 MPa in 24 hours, 80 MPa ultimate, engineered for 10-100 mm clearances under critical equipment.
What is it?
A chloride-free, natural-aggregate cementitious precision grout that flows into 10-100 mm clearances and hardens with zero bleed, no settlement and positive volume change.
Where is it used?
Machine baseplates and soleplates, precast panel and column connections, underpinning, keyways and form-and-pour concrete repairs on industrial and infrastructure sites.
Why use it?
Around 30 MPa within a day at 20 deg C lets you align and commission equipment fast; 80 MPa at 28 days carries static and moderate repetitive loads permanently.
How is it applied?
Mix a 20 kg bag with 3.3-3.4 litres of water to flowable consistency in a standard mixer, then pour continuously from one side into sealed, pre-wetted formwork.
About Master Builders Solutions MasterFlow 870
MasterFlow 870 is a high-strength, non-shrink precision grout built on a graded natural aggregate that packs densely yet flows freely at a low water content. Placed at flowable consistency, it completely fills clearances between 10 mm and 100 mm and hardens free of bleeding, settlement and drying shrinkage — so the hardened grout stays in tight, full-bearing contact with both the baseplate above and the foundation below. Strength gain is rapid: roughly 30 MPa within 24 hours at 20 deg C, rising to 80 MPa at 28 days at flowable consistency, and as high as 94 MPa when mixed to the stiffer plastic consistency. The grout meets the non-shrink requirements of ASTM C1090 and CRD-C 621, the US Army Corps of Engineers specification for non-shrink grout.
What makes it particularly relevant for Indian sites is its extended working time at high ambient temperatures. Even at 30 deg C it retains 65 percent of its initial flow after 30 minutes, which allows large or congested baseplates to be grouted in a single continuous pour, often without a pump. Space Arc Engineering stocks and installs MasterFlow 870 across Delhi NCR and pan-India, supporting plant machinery erection contractors, precast erectors and structural consultants with material supply, method statements and applicator crews.
The technical insight
Ordinary cement grout shrinks as it hydrates and dries. Under a baseplate that shrinkage breaks contact, the load funnels through a few high spots, and vibration steadily grinds the grout out — which is exactly how misalignment and coupling failures begin. MasterFlow 870 counters this with a controlled expansion system that offsets plastic and drying shrinkage: tested to ASTM C1090 (CRD-C 621), it shows positive volume change at every age from 1 to 28 days, across 10, 20 and 30 deg C. Equally important, bleeding is nil at all three test temperatures, so no water lens forms under the plate to create a weak, spongy interface. The dense natural-aggregate skeleton (plastic density about 2155 kg/m3 at 20 deg C) transfers load uniformly, and because there is no added chloride, the grout adds nothing to the chloride load around anchor bolts and embedded steel.
Where it is used
- Precision grouting of critical equipment baseplates, soleplates and column bases
- Foundations for pumps, compressors, turbines and mills needing rapid commissioning
- Structural connections for precast wall panels, beams, columns and curtain walls
- Anchor bolt pockets, dowels and keyway joints in machine and structural foundations
- Underpinning of columns and load-bearing walls
- Patching honeycombed in-situ concrete using preplaced-aggregate techniques
- Form-and-pour concrete repair where a flowable, non-shrink material is specified
Key advantages
- High early strength — about 30 MPa in 1 day at 20 deg C allows fast equipment alignment and start-up
- High ultimate strength — 80 MPa at 28 days (up to 94 MPa at plastic consistency) for permanent load transfer
- Zero bleed and positive volume change verified to ASTM C1090 and CRD-C 621
- Extended working time in hot weather — practical for single-pour grouting of large plates in Indian summers
- Flowable consistency reaches intricate, congested spaces conventional grout cannot
- No added chloride — safe in contact with anchor bolts, dowels and reinforcement
- No special equipment — mixes in a standard concrete mixer or a pail with a grout stirrer
Limitations & considerations
- Designed for 10-100 mm clearances; deeper pours need staged placement or manufacturer guidance on aggregate extension
- Cementitious system — for heavy dynamic or vibratory machinery and chemical exposure, an epoxy grout such as MasterFlow 648 is the better specification
- Strength gain slows in cold conditions — expect around 17 MPa at 1 day at 10 deg C against 30 MPa at 20 deg C
- Flow retention drops with heat (about 65 percent after 30 minutes at 30 deg C), so hot-weather pours must be planned within the working window
- Not intended for dry-pack (damp-pack) placement — MasterFlow 700 covers that method
- Water dosage must be measured, not judged by eye; excess water causes bleed and strength loss
Selection & best practice
Chip the foundation surface back to sound, laitance-free concrete with a roughened profile, and saturate it with clean water well before grouting — remove any standing water just before the pour. Build leak-proof formwork with a head box on the pouring side and about 100 mm clearance for placement. Mix full 20 kg bags with measured water: 3.3-3.4 litres per bag for flowable consistency or 2.6-2.7 litres for plastic, in a concrete mixer or with a grout stirrer, until uniform and lump-free. Pour continuously from one side only so air and water are driven ahead of the grout, never from opposite sides. Work within the flow-retention window — at 20 deg C the grout holds 90 percent of its flow for 30 minutes; at 30 deg C plan for faster placement. If site strength verification is required, cast 50 mm cubes per AS1478.2 — not cylinders. Cure exposed grout shoulders promptly and trim them to a 45-degree chamfer.
Specifications
| Product type | Cementitious high-strength non-shrink precision grout (natural aggregate, chloride-free) |
| Compressive strength, flowable at 20 deg C (AS1478.2) | 30 MPa at 1 day; 50 MPa at 3 days; 65 MPa at 7 days; 80 MPa at 28 days |
| Compressive strength, plastic consistency at 20 deg C | 42 MPa at 1 day; 94 MPa at 28 days |
| Flexural strength, flowable at 20 deg C (JIS R 5201) | 4.5 MPa at 1 day; 8.6 MPa at 28 days |
| Clearance range | 10 mm to 100 mm |
| Water demand per 20 kg bag at 20 deg C | 3.3-3.4 litres (flowable); 2.6-2.7 litres (plastic) |
| Yield per 20 kg bag | Approx. 10.8 litres flowable (about 93 bags/m3); 10.4 litres plastic |
| Setting time at 20 deg C | Initial approx. 4.5 hours; final approx. 5.2 hours |
| Standards / packaging / shelf life | ASTM C1090, CRD-C 621, AS1478.2; 20 kg bags; 12 months in cool, dry storage |
Industry use cases
Power & Energy
Grouting turbine, generator and auxiliary-equipment baseplates where the 1-day strength of about 30 MPa keeps erection and alignment schedules tight during plant construction and overhauls.
Cement & Heavy Manufacturing
Soleplates for mills, kilns, fans and crushers — full-bearing, zero-bleed contact under plates subject to static and moderate repetitive loads, with chloride-free protection for holding-down bolts.
Metro & Infrastructure
Bedding and keyway grouting for precast segments, parapets and bearings, plus underpinning works where a flowable, non-shrink, form-and-pour material is specified.
Precast Construction
Structural connections between precast wall panels, beams and columns, where high early strength lets erection crews release props and move to the next lift quickly.
Water & Process Plants
Pump and motor base grouting and honeycomb repair by preplaced-aggregate methods in treatment plants, pump houses and process units across the country.
Frequently asked questions
What clearance can MasterFlow 870 fill in a single pour?
How much water goes into one bag, and what is the yield?
When should I choose an epoxy grout instead?
Is it safe around anchor bolts and reinforcement?
How soon can equipment be commissioned after grouting?
Does hot Indian weather affect placement?
How we position Master Builders Solutions MasterFlow 870
MasterFlow 870 sits in the middle of the MasterFlow family as the workhorse precision grout for static and moderately repetitive loads. For dry-pack or damp-pack placement under plates, MasterFlow 700 is the intended product; for rotating machinery with heavy dynamic loading, chemical exposure or the tightest alignment tolerances, step up to the epoxy-based MasterFlow 648. Bases needing repair before grouting pair well with the MasterEmaco concrete repair range. As a multi-brand distributor, Space Arc can also offer Fosroc Conbextra GP2 or Sika grouts where a project specification or delivery timeline calls for an equivalent — we will recommend whichever meets your spec honestly.
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