Mapei MapeWrap C UNI-AX
Mapei MapeWrap C UNI-AX is a unidirectional carbon fibre fabric for the wet lay-up application of externally-bonded carbon fibre reinforced polymer (CFRP) strengthening to concrete and masonry substrates. The fabric is supplied as a roll in widths of 100, 200, 300, 400 and 600 mm, with standard areal weights of 300, 400 and 600 g/m² depending on the design strengthening demand. MapeWrap C UNI-AX is installed by impregnating the dry fabric with the MapeWrap 31 epoxy primer and resin (or the rapid-cure MapeWrap 21) at site, applying the wet impregnated fabric to a primed substrate, and consolidating with a rubber roller. The cured laminate develops a characteristic tensile strength of approximately 4,830 MPa per fibre direction at the 300 g/m² fabric weight, characteristic tensile modulus of approximately 230 GPa, and characteristic strain at failure of approximately 2%. TRSC specifies MapeWrap C UNI-AX as an alternative to Sika SikaWrap-300 C where the contractor's supply chain preference is for a Mapei FRP system, and on heritage masonry strengthening projects where the MapeWrap system's extensive Italian and European heritage application track record provides additional regulatory and conservation comfort.
Mapei MapeWrap C UNI-AX is TRSC's alternative CFRP fabric specification, used in three job profiles: (1) where the contractor's supply chain preference is for a Mapei FRP system (which typically locks in Mapei primers, resins and ancillary products as a system); (2) where a higher characteristic tensile strength is required than the standard SikaWrap-300 C delivers — the MapeWrap C UNI-AX 300 g/m² variant carries published characteristic tensile strength of approximately 4,830 MPa, which is meaningfully higher than the 3,500 MPa of the comparable Sika fabric and can be the engineering basis for a thinner laminate at the same design action; (3) on heritage masonry strengthening projects where the MapeWrap system's extensive Italian and European heritage application track record provides additional regulatory and conservation comfort to heritage approval authorities. The most common specification pitfalls TRSC encounters in the field are essentially identical to those for the Sika CFRP wrap system: substrate corner radius (25 mm minimum), impregnation completeness (visual transparency of wet fabric), and joint overlap detailing (100-150 mm minimum in fibre direction). One additional Mapei-specific pitfall is the choice between the MapeWrap 31 standard primer / resin and the MapeWrap 21 rapid-cure variant: the rapid-cure variant develops handling strength at 12 hours but has a shorter pot life (15 minutes at 20°C, vs. 60 minutes for MapeWrap 31), and is appropriate only on small-area applications where the contractor can complete the impregnation, application and consolidation within the pot life; field installations on large-area applications using the rapid-cure variant routinely fail because the resin cures in the impregnation pan before the fabric is applied. TRSC strengthening designs cite the appropriate Mapei resin variant for the application area and pot life requirements, and a witness hold point at the start of the first installation verifies the contractor's mixing and application sequence. The system was specified on the Prince Consort Hotel boundary wall strengthening as an alternative to traditional steel angle reinforcement, providing externally-bonded reinforcement with minimal visual impact compatible with the heritage approval framework.