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Ready-mix concrete in accordance with CAN/CSA-A23.1-M90, class C-2 should be used. It should have excellent resistance to scaling due to freeze/thaw cycles and de-icing products.
The subbase should be adequately sprayed before concrete placement. The concrete should be placed within a reasonable timeframe. It should be consolidated by hand or by mechanical methods. After placing, the concrete should be levelled to the desired grade, then floated using an aluminum or magnesium float to eliminate high and low spots.
Edging is required along the length of lateral forms and at isolation and construction joints. The concrete should be cut away from the forms using a pointed trowel before the edging tool is used. Edging should begin after the bleed water has evaporated. After the bleed water has evaporated and the edging has been done, the concrete should be floated with a wood, aluminum, or magnesium hand float to produce a smooth, even texture.
A slip-resistant surface can be produced by brooming the surface before the final set of the concrete. Esthetic joints should be done after this final finishing step.
After the finishing operations and when the bleed water has evaporated from the sidewalk surface, the concrete must be protected against excessive water evaporation. Satisfactory moisture content in the concrete must be maintained for at least 7 days to ensure proper hydration of the cement. Regardless of the curing method used, the concrete should be allowed to air dry for a period of one month following the curing period, before any de-icer salts are applied; this will give the concrete better resistance to scaling caused by the freeze/thaw cycle.
(in cases where joints have not been preformed)
Saw cut the contraction joints to a depth of 25% of the thickness of the concrete section when the concrete has sufficient resistance (6 to 18 hours after placing and before drying shrinkage cracks appear). Maximum joint spacing should be 4.5 meters.
