CEMENTITIOUS REINSTATEMENT MORTAR FOR CONCRETE PAVEMENT AND FLOORS

Notes
To avoid possible reflective cracking in the SpECtop CRM repair, it is essential that live cracks and existing joint details in the substrate be given proper attention. Live cracks should be treated by an approved method. For further information, contact SpEC Technical Department.

Preparation
Saw cut or cut back the extremities of the repair locations to a depth of at least 12mm. Break out the complete repair area to a minimum depth of 12mm up to the sawn edge. The surface should be clean and free from contamination. Where breaking out is not required, roughen the surface and remove any laitance by light scabbling or grit-blasting.

Oil and grease deposits should be removed by steam cleaning or detergent scrubbing and the effectiveness of decontamination assessed by a pull-off test.

Expose fully any corroded steel in the repair area and remove all loose scale and corrosion deposits. Steel should be cleaned to a bright condition paying particular attention to the back of exposed steel bars. Grit-blasting is recommended.

Where corrosion has occurred due to the presence of chlorides, the steel should be high pressure washed with clean water immediately after grit blasting.

The prepared area should be blown clean with oil-free compressed air and allowed to dry completely.

Priming
Reinforcing Steel
Apply one coat of SpECcoat Zn25 to all exposed reinforcing steel and allow to dry before continuing. If any doubt exists about having achieved an unbroken coating, a second application should be made and, again, allowed to dry before continuing.

Substrate
Prime using SpECbuild Primer E1.

Both of the components should be briefly stirred to ensure that any settlement products are fully suspended.

The entire contents of the curing agent should be emptied into the base component, ensuring that the sides of the curing agent tin are carefully scraped to remove all the material.

The combined materials should then be mixed using a suitable slow-speed drill and mixing paddle for 2 minutes until uniform. The sides of the tin should then be scraped and mixing should continue for a further 2 minutes. The mixed product may be applied by brush at a theoretical consumption rate of 5 m²/litre/coat.

Mixing
SpECtop CRM is a ready to use blend of dry powders.

Care should be taken to ensure the SpECtop CRM is thoroughly mixed. A forced action mixer is essential. Mix in a suitably sized drum using a SpECbuild Mixing Paddle in a slow speed (400/500 rpm) heavy-duty drill. Free- fall mixers must not be used. Mixing of part bags should never be attempted.
Place 2.3 litres of water into the mixing vessel and with machine mixing, slowly add the bag of SpECtop CRM and mix for 3 minutes until fully homogeneous. Do not mix for longer than this period as the heat developed will seriously reduce the pot life of the mixed product. Note that powder must always be added to water.

Application
While the SpECbuild Primer E1 is still tacky, apply SpECtop CRM evenly by trowel and tamp in place with a wood float to ensure full compaction. Thoroughly compact the mortar around any exposed steel reinforcement. SpECtop CRM can be applied up to 50mm thickness in single applications.
Note: The minimum applied thickness of SpECtop CRM is 12mm.