Product Overview

MC-Dur 400 is a coarse-aggregate, fibre-reinforced, polymer-modified cementitious repair mortar from MC-Bauchemie positioned at the upper end of the hand-applied structural repair mortar range — above MC-Dur 300 (10 to 40 mm) and below the spray-applied MC-RocTec SP. The product is formulated with: a Portland cement base blended with graded aggregates up to 8 to 10 mm maximum size — the coarser aggregate skeleton provides the mechanical framework for load distribution, reduces volumetric shrinkage, and gives the mortar the body required for 20 to 60 mm application depth without sagging or sliding on vertical surfaces; factory-incorporated polypropylene or steel fibres at a controlled dosage providing crack-arresting reinforcement throughout the repair volume, reducing early-age plastic shrinkage cracking and improving impact and flexural toughness of the repaired section; and redispersible polymer powder modification providing minimum 1.5 MPa pull-off adhesion bond to the substrate. The EN 1504-3 classification of MC-Dur 400 targets Class R4 (the highest classification for structural repair mortars) with compressive strength exceeding 45 MPa at 28 days — the high strength ensures that the repair mortar modulus of elasticity and thermal expansion coefficient are matched to the parent concrete, minimising differential stress at the repair boundary that can cause delamination over time. The depth range of 20 to 60 mm per layer covers the most demanding structural repair scenarios encountered in Indian infrastructure: bridge pier and pile cap section loss from chloride-induced corrosion of 30 to 50 mm depth requiring full cover restoration; retaining wall face repair after deep spalling; industrial floor trench and edge repair; and repair of construction joints with deep honeycombing. Space Arc Engineering supplies MC-Dur 400 for structural concrete repair contractors, NHAI bridge rehabilitation firms, and industrial maintenance engineers across Ghaziabad, Delhi NCR, Noida, and Uttar Pradesh.

Applications

• Bridge pier and pile cap deep section repair — reinstating large section losses (20 to 60 mm depth, covering areas from 0.5 to 10 square metres per element) on bridge piers and marine pile caps where advanced chloride-induced corrosion has consumed the full concrete cover and part of the structural section — MC-Dur 400 coarse aggregate provides the volume and strength to rebuild the full structural section in a minimum number of application layers
• Retaining wall deep face repair — repairing the face of highway and railway retaining walls where carbonation or chloride attack has caused deep spalling (20 to 50 mm) over large areas, requiring a high-build mortar capable of being applied to vertical surfaces at 30 to 50 mm depth without shuttering or temporary support
• Heavy industrial concrete repair — reinstating heavily deteriorated reinforced concrete floors, channels, and plinths in steel plants, chemical plants, and heavy engineering factories where mechanical damage, chemical attack, and thermal cycling have caused section losses of 20 to 60 mm requiring a high-strength, impact-resistant repair material compatible with the industrial operating environment
• Large-volume construction defect repair — filling deep honeycombing and segregation voids (20 to 60 mm depth) in newly constructed bridge substructures, retaining walls, and foundation elements where the extent of the defect requires a high-volume repair mortar with the structural strength to reinstate the original design section capacity
• Seaport and coastal structure repair — repairing reinforced concrete jetty deck soffits, quay wall faces, and marine pile caps in seaport and coastal environments where tidal and splash zone chloride attack has caused deep concrete section loss requiring a chloride-resistant, high-strength repair mortar with the volume and bond to reinstate the structural section
• Dam and irrigation structure concrete repair — applying MC-Dur 400 to deep surface deterioration on the faces of concrete gravity dams, weirs, canal lining sections, and sluice gate frames where hydraulic abrasion, freeze-thaw cycling, and alkali-aggregate reaction have caused deep surface loss requiring a structural repair mortar of matching strength and low permeability

Key Advantages

• EN 1504-3 Class R4 performance — highest structural repair mortar classification with compressive strength greater than 45 MPa at 28 days — ensures the repaired section matches or exceeds the strength of the original concrete and provides confidence that the repair mortar will not be the weak link in the load path of the reinstated structural element
• 20 to 60 mm per layer application depth — coarse aggregate skeleton allows thick application layers that build repair volume rapidly — a 50 mm repair depth can be completed in one layer per application session versus three or four thinner layers required with fine or medium mortar grades — reduces repair programme duration and labour cost on large-volume repair contracts
• Factory fibre reinforcement — polypropylene fibres incorporated at the factory provide three-dimensional crack-arresting reinforcement throughout the repair volume, controlling plastic shrinkage cracking at early age and providing improved impact and flexural toughness in the repaired section — particularly important for bridge and industrial structures subject to dynamic loading and vibration
• No-slump vertical surface retention — the stiff, coarse-aggregate mortar consistency is designed to be applied to vertical and overhead surfaces at 20 to 50 mm depth without sliding or sagging — eliminating the need for temporary formwork or shutter boarding for most structural repair depths up to 50 mm
• Polymer-modified adhesion bond — minimum 1.5 MPa pull-off adhesion to mechanically prepared concrete substrate — essential for deep repair mortars where the weight of a 50 to 60 mm layer creates a significant shear stress at the repair boundary — polymer modification ensures the bond strength exceeds this self-weight shear stress with adequate factor of safety
• Full MC-Bauchemie system compatibility — MC-Dur 400 is used in conjunction with MC-Bauchemie bonding primers, rebar corrosion protection coatings, and anti-carbonation surface protection coatings as a complete, integrated, warranty-covered structural repair system