Conplast P505
Non-Chloride Accelerating Admixture for Shotcrete and Cold Weather Concrete
Authorized Project Distributor — Fosroc India | Space Arc Engineering, Ghaziabad
Product Overview
Conplast P505 is a non-chloride liquid accelerating admixture from Fosroc designed specifically for use in sprayed concrete (shotcrete) and for cold weather concreting applications where rapid setting and early strength gain are critical requirements. In shotcrete applications, an accelerating admixture is essential to cause the sprayed concrete to stiffen and develop sufficient green strength within seconds of being applied to a vertical or overhead tunnel face or slope, preventing the freshly placed concrete from sliding or falling before it has hardened. Without an accelerating admixture, wet-process shotcrete cannot be applied to vertical and overhead surfaces in the thicknesses required for tunnel lining or slope stabilisation. Conplast P505 is formulated as a liquid admixture for compatibility with both wet-process shotcrete (where the admixture is added to the concrete in the delivery hose or at the nozzle) and for conventional cold weather concrete pours where the liquid form allows accurate dosing into the batch water. In cold weather concrete, the accelerating action of P505 compensates for the retarding effect of low temperature on cement hydration, ensuring that the concrete achieves stripping strength and structural loading capacity within the required time even in sub-zero or near-zero temperature conditions typical of Northern Indian winters (November to January). Non-chloride chemistry is essential for reinforced and prestressed concrete to avoid the corrosion risk associated with calcium chloride-based accelerators. Space Arc Engineering distributes Conplast P505 for tunnel construction, slope stabilisation, and cold weather infrastructure projects across Northern India.
Applications
- Wet-process shotcrete for tunnel lining and underground excavation support
- Sprayed concrete for slope stabilisation and rock face protection
- Cold weather concrete for fast-track construction in Northern Indian winter
- Rapid-setting concrete for emergency repair and patching
- Precast concrete for increased production throughput in cold weather
- Concrete repair and overlay applications requiring fast return to service
Key Advantages
- Liquid admixture for easy and accurate dosing in shotcrete and batch water
- Non-chloride — safe for reinforced and prestressed concrete
- Rapid set for early green strength in shotcrete on vertical and overhead faces
- Compensates for cold weather retardation of cement hydration
- Compatible with all Portland cements and wet-process shotcrete systems
- Proven Fosroc accelerator for tunnel and infrastructure construction in India
Technical Data
| Type | Non-chloride liquid accelerating admixture |
| Application | Wet-process shotcrete and cold weather concrete |
| Chloride Content | Nil |
| Effect | Accelerated setting and early strength gain |
| Form | Liquid for nozzle addition (shotcrete) or batch water |
| Dosage Range | 1–5 litres per 100 kg cement (shotcrete, by trial) |
Get a Quote
📞 +91 9999155255
📧 info@space-arc.com
🏢 Space Arc Engineering, Sahibabad, Ghaziabad
Frequently Asked Questions
How is Conplast P505 added in wet-process shotcrete?
In wet-process (pre-mixed) shotcrete, the accelerating admixture is typically added at the nozzle end of the delivery hose, immediately before the concrete is sprayed. A dosing pump meters the correct volume of liquid Conplast P505 into the concrete stream, where it mixes with the concrete in the last metre of hose and in the nozzle before spraying. This nozzle-addition method is preferred because it allows the accelerator dosage to be adjusted in real time by the nozzle operator without stopping the batch plant, and because the accelerator does not have time to prematurely stiffen the concrete in the delivery hose before it reaches the nozzle. The dosage rate must be calibrated by trial to achieve the required immediate stiffening at the face.
What risks are associated with over-dosing a shotcrete accelerator like Conplast P505?
Over-dosing a shotcrete accelerator causes the concrete to set so rapidly that it cannot be properly placed, compacted, or built up to the required thickness — the concrete may set and become stiff while still in the nozzle or immediately on contact with the substrate, producing a poorly compacted, rough, porous layer with very low ultimate strength. The relationship between accelerator dosage and both early strength and ultimate (28-day) strength is not linear — most accelerators cause a significant reduction in 28-day compressive strength at higher dosages. The minimum dosage needed for the required green strength should be used, and the 28-day strength at that dosage must be confirmed by testing to ensure it meets the structural design requirements.
Can Conplast P505 be used for both dry-process and wet-process shotcrete?
Conplast P505 in liquid form is primarily designed for wet-process (pre-mixed) shotcrete where the liquid can be added at the nozzle. For dry-process (gunite) shotcrete, where the dry cement and aggregate mix is conveyed in dry form and water is added at the nozzle, a powder-form accelerating admixture is typically more suitable as it can be pre-blended with the dry mix components. Consult Space Arc Engineering and the Fosroc technical team to confirm the most appropriate accelerator product and dosing method for the specific shotcrete process and project requirements.
Source Conplast P505 for Your Project
Space Arc Engineering is an Authorized Project Distributor for Fosroc India serving Delhi NCR, Ghaziabad, Noida and Uttar Pradesh.
Get Conplast P505 — Non-Chloride Accelerating Admixture for Shotcrete and Cold Weather Concrete — pricing, TDS & technical help
Space Arc Engineering is an authorized Fosroc distributor & applicator in Delhi NCR & pan-India. Fast quotes, datasheets and on-site support.
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