CONCRETE FINISHING

Good Vibrations

• There are many ways in which to finish concrete in order to get the desired finish.

• One the concrete is poured we need to ensure that all concrete faces are smooth and do not show the stones or sand that is embedded in the concrete.

• We want the faces to be smooth. This is done by vibrating the the concrete forcing the cement to the surface.

Vibrating Concrete Con’t

• Increases compressive strength and bond between concrete and rebar and decreases concrete permeability

• Decreases cold joints, honeycombing, excessive entrapped air, and segregation

• Causes concrete within a circular field of action to act like a liquid

Stop Vibrating when:•The concrete surface takes on a sheen• Large air bubbles no longer escape

Screeding

• Screeding brings   the   surface   to   the required  elevation  by  striking  off  the  excess  concrete. Two types of screeds are used in concrete finishing operations:

• Hand screed

Mechanical Screeding

Floating• Bullfloating eliminates high and low spots and

embeds large aggregate particles immediately after strikeoff. This looks like a long-handled

straight edge pulled across the concrete.

                                                              

Power Floater

Concrete Finish

• Concrete can be finished in several different ways:

• Smooth (basements, shop floors)

• Brushed (sidewalks, steps, porches)

• Stamped (sidewalks, patios, interior finish)

Stamp Concrete

• Stamp concrete is a finish that is applied when the concrete has almost completely set up.

• Large stamp pads (with a pattern) are placed on the concrete and then stamped to make an impression.

• Colour, liquid or powdered is added to give the concrete more of a interlocking brick or natural surface look.