Form Finish Repair for Concrete - Stone Rubbed Finish for offset, bulging and other irregularities within 12 to 24 Hours
Carborundum stone finish for walls and columns
a) Remove the forms while the concrete is still green, but not sooner than 12 hours nor later than 24 hours after placing the concrete.
b) After removal of forms, attend to all patching and pointing works including filling the holes left by the rods / wall ties, openings left by the removal of porous concrete and dressing of offsets and bulges.
c) Upon completion of the preceding work, clean the surface to be finished and wet it thoroughly.
d) Prepare a mortar having a stiff consistency using one part of cement to two parts by volume of sand passing through 1.18 mm IS sieve.
e) After the surface has dried such that it is just moist, spread the mortar evenly over the surface using a clean sack.
f) Start rubbing the surface lightly using a rough carborundum stone using additional mortar until the surface is evenly filled without excess of mortar.
g) Continue rubbing until the new material has become rather hard and uniform color and texture are obtained. There should be no trace of the circular rubbing marks on the surface.
h) Resume curing, keeping the surface wet for atleast 7 days.
i) After 7 days , spray the surface with water until it is thoroughly saturated. Then, starting at the top and working down, apply a grout coat with a white wash brush. The grout should consist of 1 ½ parts of light –colored clean sand passing through 600 micron IS sieve and 1 part of a mixture of white and grey cement with enough water to make a creamy paste.
j) Rub the surface again, before the grout is dried, using a smooth carborundum stone to obtain a smooth and even finish.
Carborundum stone finish for walls and columns
a) Remove the forms while the concrete is still green, but not sooner than 12 hours nor later than 24 hours after placing the concrete.
b) After removal of forms, attend to all patching and pointing works including filling the holes left by the rods / wall ties, openings left by the removal of porous concrete and dressing of offsets and bulges.
c) Upon completion of the preceding work, clean the surface to be finished and wet it thoroughly.
d) Prepare a mortar having a stiff consistency using one part of cement to two parts by volume of sand passing through 1.18 mm IS sieve.
e) After the surface has dried such that it is just moist, spread the mortar evenly over the surface using a clean sack.
f) Start rubbing the surface lightly using a rough carborundum stone using additional mortar until the surface is evenly filled without excess of mortar.
g) Continue rubbing until the new material has become rather hard and uniform color and texture are obtained. There should be no trace of the circular rubbing marks on the surface.
h) Resume curing, keeping the surface wet for atleast 7 days.
i) After 7 days , spray the surface with water until it is thoroughly saturated. Then, starting at the top and working down, apply a grout coat with a white wash brush. The grout should consist of 1 ½ parts of light –colored clean sand passing through 600 micron IS sieve and 1 part of a mixture of white and grey cement with enough water to make a creamy paste.
j) Rub the surface again, before the grout is dried, using a smooth carborundum stone to obtain a smooth and even finish.
