Product Overview

MC-Dur 400 is a factory-formulated polymer-modified cementitious repair mortar from MC-Bauchemie positioned as the general-purpose structural repair mortar for medium-thickness section repair (5 to 40 mm per layer), covering the broad majority of structural concrete patch repair scenarios encountered in building renovation and civil infrastructure maintenance. Conforming to EN 1504-3 Class R3, the mortar achieves compressive strength above 35 MPa and bond strength above 1.5 MPa — validating its contribution to structural load capacity and its compatibility with the existing concrete substrate in the repair zone. The pre-blended polymer modification (SBR or acrylic binders incorporated into the factory powder formulation) delivers three key performance improvements over unmodified cementitious patch mortars: first, substantially improved bond strength to the prepared concrete substrate without the need for a separate bonding slurry application — the polymer wets the substrate surface during the mixing and placement process and forms a tenacious adhesive matrix at the repair interface on curing; second, reduced drying shrinkage, which is the dominant cause of delamination cracking at the edges of restrained repair patches in building columns and bridge elements; and third, reduced porosity of the cured mortar matrix, slowing re-carbonation and chloride ingress through the repair zone and extending the post-repair service life. The maximum aggregate size of 3 to 4 mm allows application in the full thickness range from 5 mm feathered cosmetic patches to 40 mm deep structural reinstatements, reducing the number of different repair mortar grades a contractor needs to stock. MC-Dur 400 is compatible with MC-Baudur 1 epoxy bonding agent on highly polished or low-porosity substrates where the pre-blended polymer alone may not provide adequate adhesion. Space Arc Engineering supplies MC-Dur 400 as the standard structural repair mortar for building renovation, bridge maintenance, and civil engineering repair contractors across Ghaziabad, Delhi NCR, Noida, and Uttar Pradesh.

Applications

• Residential and commercial building column repair — reinstating spalled, carbonated, and rebar-corroded cover concrete on columns in 10 to 20-year-old reinforced concrete buildings across Delhi NCR
• Bridge and flyover maintenance patching — standard patch repair of concrete defects on bridge piers, abutments, parapets, and deck soffits during routine highway and urban bridge maintenance
• Retaining wall reinstatement — repairing erosion, impact damage, and surface deterioration on concrete retaining walls in highway, railway, and building basement applications
• Industrial and commercial building frame repair — structural reinstatement of deteriorated concrete on factory frames, warehouse columns, and commercial building structural elements
• Precast concrete element defect repair — reinstating handling damage, form defects, and manufacturing spalls on precast concrete beams, columns, and panels on site
• Water structure concrete repair — repair of concrete defects on canals, aqueducts, irrigation structures, and water retaining walls where durability and low permeability are required

Key Advantages

• EN 1504-3 Class R3 compliance — validated structural repair classification with 35 MPa compressive strength and 1.5 MPa bond strength per EN test methods
• Pre-blended polymer — factory-incorporated polymer eliminates the site-addition step required with two-pack bonding systems, reducing risk of operator error
• Wide application range — 5 to 40 mm layer thickness covers the majority of building and infrastructure repair scenarios from cosmetic patches to medium structural reinstatements
• Reduced shrinkage — polymer and controlled binder ratio lower drying shrinkage versus unmodified mortars, reducing delamination risk in restrained repair patches
• Carbonation resistance — low-porosity polymer-modified matrix reduces re-carbonation rate through the repair zone, protecting reinstated rebar cover from renewed carbonation
• IS 456 and EN 1504 compatible — suitable for use on projects with Indian national and international repair specifications