Master Builders Solutions MasterEmaco S 346
Dual shrinkage-compensated, free-flowing micro-concrete for structural repairs 25-200 mm deep — pour it into formwork instead of patching by hand.
What is it?
A single-component, dual shrinkage-compensated cementitious micro-concrete (formerly Emaco S46T) that needs only water on site to become a free-flowing, pourable repair material.
Where is it used?
Structural repair and jacketing of beams, columns, bridge members and honeycombed RCC wherever the section to reinstate is 25-200 mm deep and pouring beats trowelling.
Why use it?
Volume-stable in both the plastic and hardened states, so repairs resist cracking and de-bonding; about 15 MPa in 24 hours, with no separate bonding agent required.
How is it applied?
Mixed for 3 minutes with 3.25-3.75 litres of water per 25 kg bag, then poured or pumped into sealed formwork over a pre-soaked, keyed substrate. Never vibrated.
About Master Builders Solutions MasterEmaco S 346
MasterEmaco S 346 is Master Builders Solutions’ workhorse micro-concrete for formed structural repairs. Everything except water is factory-blended into one grey powder, so the mix a contractor produces at a remote bridge pier is the same mix produced in a Mumbai basement — no site batching of polymers, aggregates or admixtures, and no gauging errors. At a water-to-powder ratio of just 0.14 it still flows freely around congested reinforcement, filling honeycombed pockets, jacketing shutters and complex profiles that hand-applied mortars simply cannot reach. Compressive strength develops quickly, from roughly 15 MPa at one day to 40 MPa at 28 days (ASTM C109), letting formwork cycle in one to three days.
Space Arc Engineering supplies genuine MasterEmaco S 346 across Delhi NCR and pan-India as an authorised Master Builders Solutions distributor and applicator. We support consultants and repair contractors with bag-count estimates from drawings, aggregate-extension guidance for deep pours, and the companion products — rebar primer, curing compound and protective coatings — that a specification-compliant repair actually needs.
The technical insight
Ordinary cement mortars shrink twice: once while still plastic, as water settles and evaporates, and again as the hardened material dries. Either stage can pull a repair off its parent concrete. MasterEmaco S 346 counters both with a dual expansion system — a plastic-stage mechanism offsets settlement and plastic shrinkage before set, and a second, hardened-stage mechanism compensates drying shrinkage afterwards. The repair stays gently in compression against the pour edges instead of pulling away, which is why no bonding agent is specified. The very low 0.14 water-powder ratio then does the durability work: a dense, low-permeability matrix that resists ingress of aggressive elements towards the reinforcement, while graded fine aggregates let the mix flow to full compaction under its own weight — which is also why vibrating it is prohibited.
Where it is used
- Structural repair of beams, columns, slab soffits and walls where cover concrete has spalled or delaminated
- Jacketing of columns and beams for strengthening and section enhancement
- Reinstating honeycombed or under-compacted concrete in new construction to the design section
- Repair of members under repetitive or dynamic loading, such as bridge and viaduct elements
- Deep formed repairs from 25 mm up to 200 mm, including pours through congested reinforcement
- Encasement of cleaned, primed reinforcement after cutting back carbonated or chloride-contaminated concrete
- Pumped repairs to large voids where poker vibration is impossible or undesirable
Key advantages
- Dual shrinkage compensation keeps the repair volume-stable in both wet and hardened states, cutting cracking risk
- Single-component and factory-made — only water is added, so quality is predictable even on remote sites
- Free-flowing and pumpable; fills complex profiles and dense rebar cages without vibration
- No bonding agent required on properly prepared, pre-soaked substrates — one less material and one less failure plane
- Low permeability protects embedded steel from aggressive elements, extending repair life
- About 15 MPa in 24 hours allows formwork striking in 1-3 days and faster possession handback
- Extendable with 5-12 mm aggregate for pours beyond 80-100 mm, improving economy on deep repairs
- Behaviour fully compatible with host concrete, so the patch shares load rather than fighting the parent structure
Limitations & considerations
- Needs formwork and a pourable situation — for hand-applied vertical or overhead patching, use a trowelable MasterEmaco repair mortar instead
- Minimum section thickness is 25 mm; it is not intended for thin cosmetic or fairing repairs
- Pours beyond 80-100 mm must be extended with washed, saturated surface-dry 5-12 mm aggregate (up to 25 kg per bag)
- Must not be poker-vibrated — vibration segregates the mix; it compacts under its own weight
- 28-day strength is about 40 MPa; heavily loaded members needing higher grades should move up the MasterEmaco range
- Substrate must be +5 to +40 deg C, and above 40 deg C chilled mixing water is mandatory; shelf life is 6 months
Selection & best practice
Preparation decides the outcome. Break back all loose and contaminated concrete to a keyed, aggregate-exposed surface — grit or high-pressure water blasting, not impact tools — and saw-cut repair edges vertical to at least 20 mm depth to avoid feather edges. Where bars are corroded, expose 20 mm behind them, clean to Sa 2 and prime old and new steel with MasterEmaco P 130; replace any bar that has lost over 20 percent of its diameter, on the structural engineer’s advice. Erect sealed, braced formwork with a release agent and drain holes, pre-soak the substrate for 24 hours (minimum 2), then drain standing water. Mix full bags only, 3 minutes at 300-600 rpm with 3.25-3.75 litres of clean water, rest 2-3 minutes and remix briefly. Pour or pump continuously until the void fills — never vibrate. Strike forms at 1-3 days and cure immediately with MasterKure 181 or polythene sheeting.
Specifications
| Appearance | Grey free-flowing powder |
| Compressive strength (ASTM C109, 7 cm cube) | 15 MPa at 1 day; 25 MPa at 3 days; 35 MPa at 7 days; 40 MPa at 28 days |
| Water : powder ratio | 0.14 (3.25-3.75 litres per 25 kg bag) |
| Fresh density | Approx. 2,250 kg/m3 |
| Yield | Approx. 12.5 litres per 25 kg bag (mixed with 3.5 L water) |
| Application thickness | 25-200 mm; extend with 5-12 mm SSD aggregate beyond 80-100 mm |
| Application temperature | Substrate +5 to +40 deg C; material +5 to +30 deg C |
| Packaging | 25 kg bags |
| Shelf life | 6 months, stored dry on pallets away from sun and rain |
Industry use cases
Bridges & Flyovers
Reinstating spalled piers, pier caps and deck soffits on highway and metro viaducts, where dual shrinkage compensation matters under repetitive traffic loading.
Industrial Plants
Column and beam jacketing around live equipment lines — the mix pumps into tight shutters and compacts without vibration, keeping shutdown windows short.
Power & Water Infrastructure
Deep structural repairs to turbine halls, intake structures and treatment works where a low-permeability matrix must shield reinforcement from aggressive exposure.
Building Rehabilitation
Strengthening ageing housing societies and commercial frames in Delhi NCR — corroded-rebar treatment with MasterEmaco P 130 followed by formed micro-concrete encasement.
New Construction Rectification
Restoring honeycombed or under-compacted pours to the full design section before handover, without a bonding agent or redesign.
Frequently asked questions
How many bags of MasterEmaco S 346 do I need per cubic metre?
Do I need a bonding agent or primer before pouring?
What is the maximum thickness I can pour in one lift?
Can it be pumped, and should I vibrate it?
When can I strike the formwork?
Is it workable in Indian summer conditions?
How we position Master Builders Solutions MasterEmaco S 346
Within the Master Builders Solutions repair family, MasterEmaco S 346 is the standard-strength flowable option: step up to MasterEmaco S 348 where higher-grade micro-concrete is specified, or MasterEmaco S 466 for fibre-reinforced, large-volume structural rehabilitation. Every formed repair should be paired with MasterEmaco P 130 rebar primer, MasterKure 181 curing compound and, on carbonation-exposed structures, a MasterProtect anti-carbonation coating. Where a consultant’s specification names another system, Space Arc also stocks comparable micro-concretes from Fosroc (Renderoc range) and Sika, so you can match the approved make without splitting your supply chain.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.