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Finishing Concrete:
1. Bullfloating the surface immediately after screeding will
avoid surface bleeding and eliminates high and low spots on
the surface.
2. Wait for bleed water to disappear before continuing finishing.
Finishing concrete surface with bleed water present can
lower concrete’s surface strength and lead to blistering,
dusting and scaling.
3. 1/8-inch edging at all slab edges will reduce chipping.
4. Jointing includes hand tooling or saw cutting contraction
joints in slab.
5. Never spray water on the surface during the finishing
process.Water is used only after finishing is completed.
6. Depending on finish, float the surface with either wood or
magnesium floats. Floating imbeds larger aggregates beneath
the surface, produces a level surface and consolidates the
surface in preparation for troweling.
7. Trowel the surface only after floating to produce a hard,
smooth surface that will be easy to clean and maintain.
8. Saw cut contraction joints if jointing was not performed
during plastic stage. See Rule #9 below for more description.
9. Cure slab.
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RULE 8
RULE 7
PLACING & FINISHING
There are many steps to placing and finishing architectural concrete. Proper preparation and timing are imperative to ensure a
quality slab.
Placing Concrete:
1. Deliver concrete to jobsite.
2. Deposit concrete as close to its final location as possible to
minimize segregation of aggregates.
ARCHITECTURAL CONCRETE FINISHES
Finishes should match the mock-up panels approved by the owner
and architect, and consistency should be strictly adhered to in visual appearance when viewed from 20 feet away, as recognized by
American Concrete Institute (ACI). (Shaw & Sons has its own inhouse lab for generating 6-inch by 6-inch by 1-inch samples for
color and finish that can be made with the exact materials for any
specific project.)
The most popular architectural finishes are:
1. Lithocrete®, Shaw & Sons specified proprietary paving
3. Deposit concrete at the bottom of a slope and work uphill.
is structural concrete with an extremely durable surface
4. Use an appropriate concrete vibrator to consolidate placed
with imbedded materials that expand the design parameters
mix. Do not move concrete horizontally with a vibrator; it
will cause segregation.
5. Do not let concrete free fall more than 2 feet from point of
discharge if the slump is more than 4 inches, and no more
than 3 feet when the slump is less than 4 inches.
with colors, durability and exotic materials.
2. Acid-etch finish reveals the fine aggregate sand by removing
the cementatious paste without fracturing the sand particles.
Provides a suitable non-slip exterior surface.
3. Light sandblast finish reveals the fine aggregate sand, but
6. Strike-off concrete immediately after placing with a straight
fractures or frosts the integral sand and cement paste.
edge to level concrete to the top of the forms. Ensure that
4. Medium and heavy sandblast reveals both the fine and
all screeding has been performed before bleed water rises to
course aggregates and cement paste, but also fractures or
the surface.
frosts the matrix.