Sika MonoTop-122 F
Fibre-reinforced, dual shrinkage-compensated thixotropic mortar for structural reinstatement of spalled and damaged concrete.
What is it?
A single-component, cement-based repair mortar reinforced with fibres and dual shrinkage-compensated, mixed on site with water alone.
Where is it used?
Spalled columns, beams, soffits and slabs across buildings, bridges and infrastructure where reinforcement has corroded and cover concrete has broken away.
Why use it?
It rebuilds section in vertical layers up to 50 mm without formwork, resists sag and slump, and develops high 28-day strength (compressive greater than or equal to 50 MPa).
How is it applied?
Hand-troweled or wet-sprayed onto a saturated, roughened substrate in a wet-on-wet pass, then floated or sponged as it stiffens.
About Sika MonoTop-122 F
Sika MonoTop-122 F is the mortar you reach for when reinforced concrete has spalled and the section needs to be built back honestly. It is a factory pre-blended, single-component cementitious repair mortar, reinforced with fibres and formulated to be dual shrinkage-compensated, so on-site work is limited to gauging in the right quantity of clean water. Because it is thixotropic, a freshly placed layer holds its shape on vertical faces and overhead soffits instead of slumping, which is exactly what a contractor needs when reinstating a corroded column or a bridge beam without erecting shuttering. In practical Indian site conditions across Delhi NCR and beyond, that translates to fewer passes, less waste, and a repair that actually stays where the trowel left it.
The product sits in the middle of Sika’s MonoTop repair family and is aimed squarely at real structural reinstatement rather than cosmetic skim work. It handles thicknesses from 5 mm up to 50 mm in a single vertical pass, and 5 to 15 mm overhead, so shallow honeycombing and deep spalls can both be addressed with one material. Space Arc Engineering supplies it as an authorised channel for Sika India, and we position it for RCC rehabilitation projects where the specification calls for a proven, high-strength, sprayable mortar with dependable bond back to the parent concrete.
The technical insight
The performance of MonoTop-122 F comes down to three things working together. First, dual shrinkage compensation counters both the early plastic shrinkage and the later drying shrinkage that normally opens a hairline gap between a repair and the substrate; keeping that interface tight is what preserves long-term bond and keeps water and chlorides from tracking back to the steel. Second, the thixotropic rheology means the mortar behaves like a stiff paste at rest but shears easily under the trowel or through a spray gun, which is why a 50 mm vertical build stays put and why complex profiles can be sprayed with minimal rebound. Third, the fibre reinforcement bridges micro-cracks as the mortar cures, adding tensile toughness to a matrix that would otherwise be brittle. The result is a bonded, monolithic patch that shares load with the surrounding concrete rather than sitting on it as a loose plug.
Where it is used
- Reinstating spalled and delaminated cover concrete on columns, beams and slabs
- Repairing carbonation and chloride-induced damage around corroded reinforcement
- Vertical section build-up to 50 mm in a single pass without formwork
- Overhead soffit repairs on bridge decks and building undersides (5-15 mm)
- Filling honeycombing, blowholes and pour defects in structural RCC
- Wet-spray reinstatement of complex or heavily corroded profiles
- Rehabilitation of bridge, flyover and infrastructure superstructure elements
- Patch repairs on industrial and commercial building frames
Key advantages
- Single-component – only clean water is added on site, cutting dosing errors
- Dual shrinkage-compensated for a tight, durable bond to the parent concrete
- Thixotropic and non-sag, so vertical layers up to 50 mm hold without shuttering
- Fibre-reinforced for improved crack resistance and tensile toughness
- Sprayable, letting crews reinstate complex profiles with minimal rebound
- High strength gain: compressive greater than or equal to 50 MPa and flexural greater than or equal to 9 MPa at 28 days
- Strong tensile adhesion (greater than or equal to 12 MPa at 28 days, ASTM C882) back to sound concrete
- Suits both structural reinstatement and cosmetic making-good with one product
Limitations & considerations
- Pot life is only around 40 minutes at 20 degrees C, and shorter in hot weather – mix in batches you can place in time
- Do not add water beyond the 4.5-4.8 litres per bag dosage; over-watering causes discolouration and cracking
- Requires ambient and substrate temperatures between +10 and +40 degrees C during application
- Single-pass thickness is capped at 50 mm vertical and 15 mm overhead; deeper repairs need staged lifts
- Not a self-levelling or free-flowing grout – it is a trowel/spray-applied thixotropic mortar
- Short 6-month shelf life, so stock must be rotated and kept dry between +5 and +40 degrees C
Selection & best practice
Success starts with the substrate, not the mortar. Cut back all delaminated, weak or carbonated concrete to a sound base using mechanical breakers or high-pressure water jetting, and expose corroded steel fully so it can be cleaned of rust and mill scale and primed. Angle-cut the perimeter of the repair area between 90 and 135 degrees to the surface to avoid feather edges and undercutting. On a well-roughened substrate a bonding primer is usually not needed – instead pre-soak the concrete to a saturated surface-dry (SSD) condition with a darkened matt look and no free-standing water. Where a primer is specified, work the mortar in wet-on-wet while the primer is still tacky. Mix mechanically with a slow-speed drill (max 500 rpm) for at least three minutes, adding roughly 80-90 percent of the water first and the balance after, and never re-temper with extra water once it stiffens. Press the mortar firmly onto the substrate, finish as it starts to set, and then cure and protect the repair from direct sun, strong wind and early moisture loss.
Specifications
| Product type | Single-component, fibre-reinforced, dual shrinkage-compensated thixotropic cementitious repair mortar |
| Pack size | 30 kg bag |
| Layer thickness | 5-50 mm vertical / 5-15 mm overhead per pass |
| Mixing water | Water : powder = 0.15-0.16 by weight (approx. 4.5-4.8 litres per bag) |
| Fresh mortar density | approx. 2200 kg/m3 at 0.16 water:powder |
| Compressive strength | greater than or equal to 20 MPa (1 day), greater than or equal to 35 MPa (7 days), greater than or equal to 50 MPa (28 days) – ASTM C109 |
| Flexural (tensile) strength | greater than or equal to 6 MPa (7 days), greater than or equal to 9 MPa (28 days) – EN 196-1 |
| Tensile adhesion strength | greater than or equal to 8 MPa (7 days), greater than or equal to 12 MPa (28 days) – ASTM C882 |
| Pot life / application temperature | approx. 40 min at +20 degrees C; ambient and substrate +10 to +40 degrees C |
Industry use cases
Bridges & Infrastructure
Reinstating spalled soffits, beams and piers on bridges and flyovers where sprayable, non-sag application avoids costly formwork over traffic.
Commercial & High-Rise Buildings
Structural patch repair of corroded RCC columns and beams in older frames, restoring section and cover in vertical lifts up to 50 mm.
Industrial Structures
Making good honeycombing, pour defects and chemical/carbonation damage on load-bearing frames and support structures.
Water-Retaining & Marine Structures
Rebuilding chloride-attacked concrete around reinforcement where a dense, well-bonded, shrinkage-compensated mortar is essential.
Public & Institutional Assets
Rehabilitation of ageing government, transport and utility structures under specified concrete-repair contracts across Delhi NCR and Pan-India.
Frequently asked questions
Is Sika MonoTop-122 F a structural or cosmetic repair mortar?
How thick can I apply it in one pass?
How much water do I add per bag?
Do I need a bonding primer?
What is the pot life and working time?
What pack size does Space Arc supply and how is it stored?
How we position Sika MonoTop-122 F
Sika MonoTop-122 F is the mid-strength workhorse of Sika’s structural repair range. Where a repair needs a bonding coat and rebar corrosion protection first, pair it with Sika MonoTop-610 (bonding primer / anti-corrosion coating), and finish exposed repairs with a Sikagard protective anti-carbonation coating for long-term durability. On flowable, formwork-based reinstatement or when a self-compacting micro-concrete is specified instead of a hand-applied mortar, look at Sika MonoTop-412 IN. Beyond the Sika family, Space Arc also stocks equivalent high-build repair mortars from Fosroc (Renderoc range) and Dr. Fixit, so we can match whatever a project specification names. Talk to us if you need help aligning the mortar grade to the EN 1504 class in your repair specification.
Fosroc Renderoc HB45 — Choose the Fosroc option when the specification calls out an EN 1504-3 Class R4 mortar or when the rest of the project is already standardised on the Fosroc Renderoc repair system.
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Source Sika MonoTop-122 F for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.