Buildhub PatchMax Structural Repair Cement 5kg

The Buildhub PatchMax Structural Repair Cement is a Class R3 repair mortar system formulated for structural and semi-structural concrete repair applications where simple patching products with insufficient mechanical properties would compromise the long-term integrity and service life extension objectives of the repair. Achieving 45 MPa compressive strength at 28 days and a direct pull-off bond strength exceeding 2.0 MPa, PatchMax provides the mechanical performance specified in EN 1504-3 Class R3 repair mortars for structural concrete repair under BS EN 1504-3.

Shrinkage compensation is built into PatchMax through a carefully calibrated system of expansive mineral admixtures that generate a controlled volume expansion during the early setting period, offsetting the drying shrinkage that would otherwise generate tensile stress at the repair-substrate interface and progressively loosen the bond between repair and parent concrete. This shrinkage-compensating behavior is critical in large-area and full-depth repairs where the exposed geometry of the repair provides maximum opportunity for drying shrinkage to cause delamination.

The polymer modification of PatchMax serves multiple functions: it increases the bond strength to the prepared concrete substrate, improves the impact and abrasion resistance of the hardened repair surface, provides a degree of crack-bridging flexibility that accommodates minor differential movement between repair and parent concrete, and improves the overall water resistance of the repair patch compared to unmodified cementitious mortars.

PatchMax can be applied by trowel in single lifts of 10mm to 50mm, or in multiple lifts up to 80mm total depth with appropriate interlayer treatment. Substrate preparation must include mechanical removal of all defective concrete, cleaning to a clean bare concrete surface, and application of Buildhub PrimeCoat bonding agent to achieve the specified bond performance. Full application guidance is supplied with every unit.