Inject cracks wider than 0.25 mm with Sikadur-52 or other suitable Sikadur-injection
resin.
External corners must be generally rounded to a minimum radius of 20 mm or as per
the design specification. This can be achieved either by grinding or by building up with
Sikadur mortars. Internal corners shall be smoothed by trowelling epoxy mortar into
the corners.
The surface to be bonded must be level (max. deviation 2 mm per 0.3 m length), with
steps and formwork marks not greater than 0.5 mm. High spots can be removed by
abrasive blasting or grinding.
Repairs to substrate and concrete surface irregularities such as blowholes or voids
shall be filled with an approved repair mortar. Sikadur-41 or a mixture of Sikadur-30
and Sikadur-501 quartz sand (mix ratio 1:1 max. parts by weight) serves best.