Fosroc Patchroc RSP
Rapid-setting, self-compacting patch repair concrete for pavements, runways and floors — back to traffic in hours, not days.
What is it?
A ready-to-use, pre-blended micro-concrete of inorganic cements, graded aggregates and strength-controlling additives. Add only clean water on site to get a fluid, self-compacting, high-early-strength repair concrete with no chloride admixtures.
Where is it used?
Emergency reinstatement of damaged or deteriorated horizontal concrete — airport runways and aprons, highways and toll roads, industrial floors, loading bays and any pavement where wheeled traffic must return fast. Usable internally and externally.
Why use it?
It restores load-bearing concrete in hours instead of days: pedestrian traffic in 1-2 hours and vehicular traffic in about 4 hours, while self-compacting to eliminate honeycombing and voids without poker vibration.
How is it applied?
Saw-cut and break out to a square edge (min 20 mm), saturate the substrate, force-action mix one 30 kg bag with about 5-5.5 L water, then pour or pump in a single continuous operation within 10 minutes. Finish, then cure immediately with a Concure curing compound.
About Fosroc Patchroc RSP
Fosroc Patchroc RSP (Rapid Setting Patch) is a single-component, cement-based repair concrete supplied as a factory-blended powder with graded aggregates. On site you add only clean potable water to produce a free-flowing, self-levelling micro-concrete that compacts under its own weight. It was developed for one job above all: getting a trafficked concrete surface — a runway, an apron, a highway bay, a warehouse floor — repaired and back in service within the same shift, where conventional repair mortars or fresh concrete would keep the area closed for days. The chemistry is a blend of inorganic cements, special fillers and additives that deliberately control the rate of strength gain, so the mix stays workable long enough to place yet develops structural strength fast. It contains no added chlorides, exhibits good thermal compatibility with the parent concrete, and offers high abrasion and weather resistance once cured. For Indian contractors and project owners juggling tight closure windows on operational pavements, this is the practical appeal — minimal downtime with predictable, specification-grade performance. Space Arc Engineering supplies and applies Patchroc RSP across Delhi NCR and on a Pan-India basis as an authorised Fosroc distributor and applicator.
The technical insight
The defining characteristic of Patchroc RSP is its engineered strength-development curve. Tested to ASTM C109/C109M at a water:powder ratio of 0.18 and 25±2°C, it reaches roughly 30-35 N/mm² in just 4 hours, 40-50 N/mm² at 1 day, 51-60 N/mm² at 7 days and 61-70 N/mm² at 28 days. Initial set is 10-15 minutes and final set 30-40 minutes, which is why placing discipline matters — the mixed material must be poured within about 10 minutes to exploit full fluidity. Because it is self-compacting it fills around reinforcement and into irregular profiles without vibration, removing the honeycombing risk that plagues stiff hand-packed mortars. The trade-off is thickness and bay-size control: it is designed for a nominal 100 mm lift in a single pour, with a 20 mm minimum (to avoid feather-edge failure) and a 4 m² maximum neat bay. For deeper sections up to 250 mm, the product is bulked with silt-free 8-12 mm aggregate and zone-2 sand to manage the heat of hydration, with bays then up to 12 m² and a strict 1:1 aggregate-to-product limit by dry weight. Understanding this — neat for shallow trafficked patches, aggregate-extended for deep mass repairs — is the key to specifying it correctly.
Where it is used
- Emergency reinstatement of spalled or deteriorated airport runways and aprons requiring fast return to service
- Full-depth and partial-depth pothole and joint repairs on highways and toll roads
- Industrial and warehouse floor repairs, loading docks and material-handling areas subject to wheeled traffic
- Repairs to concrete pavements where traffic closure windows are limited to a single shift or overnight
- Self-compacting reinstatement around exposed reinforcement and irregular break-out profiles
- Deep section repairs up to 250 mm when bulked out with graded aggregate to control temperature rise
Key advantages
- Rapid strength gain — pedestrian traffic in 1-2 hours and vehicular traffic in approximately 4 hours
- Self-compacting and free-flowing — eliminates honeycombing and voids without poker vibration
- High early and ultimate strength with good abrasion and weather resistance (up to 61-70 N/mm² at 28 days)
- Ready to use — only clean water is added on site, reducing batching error and quality variation
- Contains no chloride admixtures, protecting embedded reinforcement
- Economical for deep repairs — can be bulked out with graded aggregate up to a 1:1 ratio
- Good thermal compatibility with the parent concrete, reducing differential-movement stress
Limitations & considerations
- Short working window — must be placed within about 10 minutes of mixing, demanding adequate mixing capacity and labour for continuous placement
- Minimum 20 mm applied thickness; feather-edging is not permitted
- Aggregate must NOT be added between 20 mm and 100 mm thickness without specific Fosroc advice
- Neat bay size limited to 4 m² (12 m² when aggregate-filled), so very large areas need staged pours or Paveroc instead
- Requires a forced-action mixer; free-fall mixers must not be used and part bags must never be mixed
- Must not be applied below 5°C substrate/air temperature; vulnerable to surface scour from heavy rain before final set
- Cement-based — releases alkalis when wet and requires immediate curing, PPE and standard cementitious-handling precautions
Selection & best practice
Saw-cut the repair perimeter to at least 20 mm to create a square edge and avoid feather-edging, then break out the full area to a minimum 20 mm depth, removing all dust, laitance, oil, grease and unsound concrete; verify decontamination with a pull-off test where critical. Saturate the prepared substrate by flooding with clean water and remove standing water just before placing so the concrete is saturated surface-dry; where soaking is impractical, scrub in Nitobond AR primer and place Patchroc RSP while it is still tacky. Use a forced-action mixer (or an approved spiral paddle on a slow-speed heavy-duty drill), always add powder to water, and add powder to roughly three-quarters of the 5-5.5 L water before topping up. Pour or pump each repair in one continuous operation within 10 minutes, finish without over-working, and cure immediately with a Concure compound (supplement with taped-down polythene in hot or fast-drying conditions). In cold weather use warm water up to 30°C; in ambient above 30°C store in shade, use cool water and prefer night-time placement to avoid evaporation cracking.
Specifications
| Material type | Pre-blended dry powders + graded aggregates; inorganic cements, fillers and additives (self-compacting micro-concrete) |
| Compressive strength (ASTM C109/C109M) | 30-35 N/mm² @ 4 hrs; 40-50 N/mm² @ 1 day; 51-60 N/mm² @ 7 days; 61-70 N/mm² @ 28 days |
| Flexural strength | 30-40 kg/cm² @ 4 hrs; 55-65 kg/cm² @ 7 days |
| Setting time | Initial set 10-15 min; final set 30-40 min |
| Time to traffic | Pedestrian 1-2 hrs; vehicular approx. 4 hrs |
| Applied thickness | Min 20 mm; nominal 100 mm single application; up to 250 mm bulked with aggregate |
| Water addition | Approx. 5-5.5 L per 30 kg bag (neat); 4.7-5.2 L when bulked; w/p ratio 0.18 (test basis) |
| Bulked mix (100-250 mm) | 30 kg Patchroc RSP + 4.7-5.2 L water + 12.5 kg of 8-12 mm aggregate + 7.5 kg zone-2 sand (max 1:1 aggregate:product by dry weight) |
| Bay size | Up to 4 m² neat; up to 12 m² when aggregate-filled |
| Yield / coverage | Approx. 15.5 litres per 30 kg bag (0.76 m² at 20 mm thickness) |
| Working time | Place within 10 min of mixing |
| Pack size | 30 kg bags (per TDS); India-market Patchroc range also offered in 25 kg |
| Primer / curing | Nitobond AR primer (where soaking not possible); cure with Concure P / Concure PI |
| Chloride content | No added chloride admixtures |
| Min application temperature | 5°C substrate/air |
| Shelf life | 12 months in dry, unopened original packaging |
Industry use cases
Aviation infrastructure
Overnight reinstatement of spalled runway and apron slabs at operating airports, where the surface must carry aircraft and ground-handling traffic by the next morning — the ~4-hour vehicular strength and self-compacting flow suit confined, deep break-outs around dowels.
Highways and toll roads
Rapid full-depth and joint repairs on national highways and toll plazas during short lane-closure windows, restoring trafficable strength within a single shift to minimise congestion and penalty exposure.
Industrial and warehousing
Repair of damaged factory floors, loading docks and forklift runways in plants that cannot afford extended shutdowns; abrasion resistance handles continued wheeled and pallet traffic.
Ports and logistics yards
Reinstatement of container-yard and hardstanding pavements subject to heavy point loads, using aggregate-bulked mixes for deep sections up to 250 mm while controlling heat of hydration.
Urban roads and municipal works
Emergency pothole and utility-cut reinstatement on city streets and bus depots where lanes must reopen quickly, with night-time placement recommended in peak summer to avoid evaporation cracking.
Frequently asked questions
How soon can traffic use a Patchroc RSP repair?
What thickness can Patchroc RSP be applied at?
How much area does one bag cover?
Does Patchroc RSP need a primer?
Why does it have to be placed so quickly?
How is Patchroc RSP different from Patchroc GP and Renderoc?
How we position Fosroc Patchroc RSP
Within the Fosroc concrete-repair portfolio, Patchroc RSP sits at the rapid-traffic-return end of the horizontal repair family. It complements rather than replaces its siblings: Patchroc GP is the fast-setting general-purpose patching mortar for smaller, less time-critical defects, while Paveroc is Fosroc’s recommendation for reinstating very large pavement areas beyond the practical bay sizes of a patch product. Companion products complete the system — Nitobond AR as bonding primer where the substrate cannot be soaked, and the Concure curing-compound series to protect the fresh surface. For vertical and overhead structural repairs the Renderoc range (HB, LA, SP and related grades) is the correct choice, and for free-flowing structural grouting Conbextra applies. Against the wider Indian market, credible alternatives in the rapid pavement-repair niche include Sika’s fast-setting repair concretes and patch-repair systems, MBS (MBCC/Master Builders Solutions, formerly BASF) MasterEmaco rapid-hardening repair mortars, STP’s repair range, and at the trade/retail tier Dr. Fixit patch-repair products — though the latter is more commonly specified for waterproofing and general repair than for trafficked-pavement micro-concrete. Patchroc RSP’s particular strengths are its self-compacting flow, its no-chloride formulation and its well-documented strength-versus-time data, which make it straightforward to specify and verify on time-critical pavement, runway and floor projects. As an authorised Fosroc distributor and applicator serving Delhi NCR and Pan-India, Space Arc Engineering can supply Patchroc RSP with the matching primer and curing system and advise on the neat-versus-aggregate-bulked mix design for your specific repair depth.
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