Technical Support
Tech support is a tutorial,
Explaining proper way to expose
aggregate in freshly placed ready-mix concrete. We will go through
all
the different practices for both
Vertical
& Horizontal
exposure. Including
what chemical reactions are taking place. Also learn about
Concrete, and how it works. What
are Admixtures? not to be confused with
Additives
How to
re-enforce concrete to make a structure. or just to prevent cracking.
How do I
measure
the amount of concrete I need. Use our on-line
concrete
calculator. Try our online
Conversion
Calculator
To convert anything from Metric to Imperial, its fast and easy.
Guidelines
for installing a
Driveway
, Patio
or Sidewalk
the importance of the excavation and type
of gravel used to create
a
base
for driveway to be poured upon. What will make
your investment last.
How to get the most out of your design.
Click here and watch a driveway
poured and washed
How
about Repairing
or Restoring
concrete, our data base should have everything you need to know, If you can't
find it there. Try
Ask
an Expert
There are many
different Techniques
to
achieving a textured or exposed aggregate finish, in freshly poured
concrete Depending on the desired finish, or depth of etch. Most of
these techniques require the use of a product called
Retarder. Because the chemical works as a catalyst, to slow and prevent the
natural chemical reaction of portland cement, Thus the term Retarder.
Also
there is a great difference in the relationship between
Vertical
and Horizontal
retarders,
due in part to how they need be applied to achieve the desired texture, on the
desired surface.
We strongly
recommend you use a professional
How
exposed-aggregate concrete finishes produced?
There are three ways of obtaining exposed-aggregate finishes on
concrete slabs: seeding a select aggregate into the concrete surface, the
monolithic technique where a select aggregate, usually gap-graded, is mixed
throughout the batch of concrete, and exposing gap-graded aggregates in a
special topping course.
The process for producing
monolithic exposed-aggregate
finishes is as follows:
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1) Place the concrete containing the
chosen aggregate in a normal manner in which you fill the forms with the
material and rod the surface with a straight edge (typically a straight
2" X 4" board) with a sawing motion, back and forth across the form from
side to side. Then close the surface as usual.
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2) Spray the
surface with
retarder. This can be obtained at any contractors supply
house. Retarder does typically contain
sugars but the formulations that are designed for use with concrete are
strongly recommended for a more consistent performance. The
retarder will slow the set characteristics
of the discrete surface layer allowing the interior to harden while the
exterior surface remains soft or .
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3) The third phase is the difficult
part. When the concrete has become hard enough to carry your weight
without displacing the aggregate the surface is washed with a hose and
scrub brush to remove the top layer of cement paste. Care must be taken
not to displace the aggregate and not to expose the aggregate
too deeply (this can cause the aggregate to
lose bond and/or be displaced). Caution: A too long delay in this part
of the process can create extreme difficulty in the removal of the top
paste layer. The retarder slows the set of
the top surface but can not stop it completely. After the desired
surface has been achieved the slab should be acid washed then sealed
with a clear sealer and curing compound (also found at your local
contractor supply house).
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Here are some
useful links
VIDEO
OF EXPOSED AGGREGATE
Recipe for strong
Concrete
Concrete
Terms Glossary
WHAT'S A POP-OUT
PLACING
AND FINISHING CONCRETE
HOW
TO EXPOSE FLATWORK
