Product Overview

MC-Nafuplan EB is a single-component, solvent-free, moisture-curing polyurethane elastic sealant from MC-Bauchemie for sealing structural movement joints in concrete construction. The product cures on exposure to atmospheric moisture through urethane crosslinking to form an elastomeric, permanently flexible seal with high elongation at break (greater than 400 percent) and excellent elastic recovery (greater than 80 percent after 24 hours following 25 percent joint movement) — the two properties that define a durable movement joint sealant. The fundamental difference between MC-Nafuplan EB (elastic PU sealant) and the rigid epoxy injection resins or cementitious repair mortars is the design intent: a movement joint sealant must accommodate repeated, cyclic joint movement over the structure life without cracking, debonding, or fatigue failure — this requires a flexible, elastic material that deforms with the joint and recovers its original dimensions when the joint closes. The design movement capacity of MC-Nafuplan EB (typically plus or minus 25 percent of the nominal joint width) determines the minimum joint width that can be sealed: if the joint is designed for plus or minus 5 mm total movement, the joint must be a minimum of 20 mm wide to keep the sealant within its movement capacity (5 mm movement on 20 mm joint = 25 percent movement factor). The joint geometry — specifically the width-to-depth ratio of the sealant bead — is the most critical design parameter: the correct geometry is width equal to depth (1:1 ratio) for joints up to 20 mm wide, and width equal to twice the depth (2:1 ratio) for wider joints — using a closed-cell polyethylene backer rod to control sealant depth is mandatory for all movement joints wider than 10 mm. Space Arc Engineering supplies MC-Nafuplan EB for waterproofing contractors, civil construction companies, bridge maintenance agencies, and car park operators across Ghaziabad, Delhi NCR, Noida, and Uttar Pradesh.

Applications

• Structural expansion joint sealing in multi-storey residential and commercial buildings — sealing the 20 to 50 mm wide expansion joints between structural blocks in reinforced concrete frame buildings in Ghaziabad and Delhi NCR where thermal expansion and contraction, foundation differential settlement, and seismic deformation create cyclic joint movement of 5 to 15 mm over the building life — MC-Nafuplan EB provides the durable elastic seal that prevents water ingress at expansion joints while accommodating the full design movement range
• Car park deck expansion joint sealing — sealing movement joints in multi-storey and basement car park decks where vehicle traffic, thermal cycling (car park decks experience 40 to 60 degrees Celsius temperature range between summer midday and winter night in North India), and structural deflection under vehicle loading impose demanding cyclic movement and mechanical abrasion on the joint sealant — MC-Nafuplan EB for car park deck joints must be combined with a polyurethane traffic-grade top coat or nosing system for the traffic wheel-load bearing area
• Bridge movement joint sealing — sealing expansion joint gaps between bridge deck spans, between deck and abutment, and at pier-cap expansion bearings in highway bridges, flyovers, and railway over-bridges where the joint sealant must accommodate thermal expansion over a 100 to 200 metre span (creating joint movements of 20 to 40 mm in large bridges), live load rotation, and wind-induced longitudinal displacement — bridge expansion joints are one of the most demanding sealant applications in terms of movement range, traffic load, and exposure to water, chloride, and UV radiation
• Basement and underground structure perimeter joint sealing — sealing the construction joint between basement raft slab and perimeter retaining walls, and expansion joints within basement structures, where the joint sealant must resist hydrostatic water pressure from the surrounding groundwater while accommodating settlement-induced movement — in basement structures, the hydrostatic head from groundwater at typical Delhi NCR basement depths (3 to 8 metres) creates a water pressure of 30 to 80 kPa on the joint sealant; MC-Nafuplan EB provides the pressure-resistant elastic seal for this critical waterproofing application
• Industrial floor expansion joint sealing in warehouses and factories — sealing the contraction and expansion joints in industrial concrete floors in logistics warehouses, cold storage facilities, and manufacturing plants where forklift traffic, pallet jack loads, and heavy roller conveyors impose severe mechanical demands on joint sealants — in industrial floors, the joint sealant depth must match the floor slab thickness to support the joint edge under wheel load, and the sealant hardness must be adequate to prevent joint edge chipping from heavy traffic

Key Advantages

• High elongation at break — greater than 400 percent elongation at break (ISO 8339 or equivalent) ensures the sealant can accommodate the extreme joint deformation that may occur during construction settlement, seismic events, or accidental overloading without cohesive failure through the sealant body — a sealant with 400 percent elongation can stretch to 5 times its original length before breaking, providing a substantial safety factor over the design movement range
• Excellent elastic recovery — greater than 80 percent elastic recovery after 25 percent joint movement cycling (ISO 7389 or equivalent) — elastic recovery is the property that allows the sealant to return to its original dimensions after joint closure, maintaining a tight seal throughout the thermal cycle — poor elastic recovery (permanent set) causes the sealant to accumulate slack over multiple movement cycles, eventually leading to wrinkle formation and loss of seal integrity
• Moisture-curing — no mixing required — single-component moisture-curing polyurethane that cures with atmospheric humidity — the moisture-curing mechanism gives good applicability in Indian monsoon conditions (50 to 90 percent relative humidity) where two-component sealants with polyol-isocyanate mixing require careful ratio control to achieve full cure; single-component MC-Nafuplan EB cures reliably in all Indian humidity conditions from January dry season to July monsoon
• Primerless adhesion to concrete and mortar in most conditions — adhesion to clean, sound concrete and cementitious surfaces without a separate primer in most dry to slightly moist conditions, simplifying the application procedure and reducing the risk of primer application errors — a primer coat (MC-Primer PU) is still recommended for below-ground joints with water contact and for substrates with high porosity or contamination
• UV and ozone resistance — the polyurethane formulation provides good resistance to UV degradation and ozone cracking compared with some sealant types — suitable for external exposure in exposed bridge deck joints and external building expansion joints without an overcoat in most Indian locations