Concrete Repair Mortar Selection
Selecting a repair mortar starts with the reason the concrete deteriorated and the role of the repaired area. A shallow surface defect, a deep formed repair and a structural section do not automatically require the same material. Record the location, depth, exposure, condition of reinforcement and whether the repair must carry load before comparing bags or compressive-strength figures.
Placement method narrows the choice. A hand-troweled vertical or overhead patch needs a mortar that can remain in place at the specified thickness. Green Build Egypt lists GB Rep as a polymer-modified, fiber-reinforced repair mortar and HiRep as a polymer-modified, fiber-reinforced cementitious mortar. The allowable layer thickness and preparation for each must be taken from its current datasheet, not inferred from its product family.
A large formed void may instead suit a flowable micro-concrete such as GBGrout MC, while UltraPoxy CRep is described as a semi-fluid epoxy-cement repair material for applications including concrete floor voids. Those are different placement and material systems. Do not substitute one for another without checking bond, dimensional behavior, service exposure and the designer's requirements.
The existing concrete must be sound enough to support the repair. Remove deteriorated material to the extent specified, address exposed or corroded reinforcement and prepare a clean bonding surface. Check required substrate moisture, mixing, application temperature and curing with the selected product. Strong repair material on a weak or contaminated substrate can still fail at the interface.
Define acceptance in advance: repair dimensions, bond and finish requirements, curing and inspection. For structural deterioration or recurring corrosion, the engineer should decide whether a mortar patch alone addresses the cause. Use the product datasheet to complete a project-specific repair method rather than selecting on strength alone.