BASF MasterEmaco S 488 CI
MasterEmaco S 488 CI (Master Builders Solutions, formerly BASF Construction Chemicals) is a one-component, polymer-modified, fibre-reinforced, shrinkage-compensated cementitious repair mortar with an integral migrating corrosion inhibitor (CI) for the structural repair of reinforced concrete. The product is classified as Class R4 under EN 1504-3 and is supplied as 20 kg bags of pre-blended dry mortar, mixed with 3.0 to 3.4 litres of clean water per bag, and applied by hand or wet-spray. The integral migrating corrosion inhibitor is the defining feature of the CI variant: amine-based corrosion inhibitor molecules diffuse from the cured repair mortar into the surrounding concrete substrate over time, providing extended corrosion protection to reinforcement beyond the patched area. This is the engineering reason TRSC specifies MasterEmaco S 488 CI on substrates with measurable chloride contamination at depth — the migrating inhibitor extends corrosion protection into the unpatched cover zone where chloride profiling has identified active corrosion risk that does not yet justify patch repair. The product develops compressive strength exceeding 60 MPa at 28 days and bond strength exceeding the EN 1504-3 R4 minimum of 2.0 MPa.
MasterEmaco S 488 CI is TRSC's preferred R4 patch-repair mortar where chloride profiling has identified active corrosion risk in the unpatched cover zone surrounding the patch — a common condition on marine, coastal and de-icing-salt-exposed concrete assets where the patches are confined to the most-deteriorated locations but the surrounding cover concrete carries chloride content above the corrosion threshold. The migrating corrosion inhibitor in the CI variant is the engineering differentiator: published BASF technical data and independent research show measurable amine inhibitor migration into adjacent concrete over 12-24 months, extending the corrosion-protection radius of each patch by typically 100-200 mm. The most common specification pitfalls TRSC encounters in the field are: (1) substituting the non-CI variant — MasterEmaco S 488 (without CI) is a Class R4 mortar without the migrating inhibitor; the visual product is identical and the contractor's site preference for the lower-cost non-CI variant is a common substitution that defeats the engineering basis for the specification; (2) substrate preparation — the migrating inhibitor diffuses into the substrate by mass-transfer driven by moisture gradient; substrates that are not saturated surface dry at application impair the diffusion mechanism and reduce the achievable protection radius; (3) application thickness — the migrating inhibitor concentration in the cured mortar reduces with reduction in repair depth; below 15 mm the inhibitor reservoir is insufficient to deliver the published migration radius, and TRSC specifications enforce a minimum 15 mm patch depth where the CI mechanism is the basis for specification. Site QA includes batch numbers (CI variant batch numbers begin with a specific code that distinguishes them from non-CI batches), water-addition record per bag, ambient temperature recording, and substrate moisture verification at the start of each pour. The product was specified on the 12 Creek Street facade remediation where chloride profiling indicated active corrosion at discrete locations within a chloride-contaminated cover zone — a textbook engineering condition for the migrating-inhibitor approach.