Since using a polymer rather than Portland cement creates a considerably more costly material, polymer concretes are used only in applications where its higher cost is offset, for instance by it’s properties, lower labor cost or lower energy expenditures in processing and handling. Construction engineers and architects, therefore, need to be aware of its capabilities and limitations when considering polymer concrete for specific applications.
If you are pouring your own concrete the following cement slab finishing techniques should be helpful. The idea is to produce a progressively smoother, more even surface with each progression. You will use a different tool for each step in the process.
Unfortunately it is not common to make a concrete slab to use just for practice. So start small, maybe with a trash can slab. Over time as you master the techniques through experience you will be able to produce professional results.
Architectural concrete is precast or cast-in-place concrete which will be permanently exposed to view in a building. When using it as a construction technique, special care is needed in selecting the concrete materials, method of forming, location and finishing, to achieve the required architectural appearance.
Pouring concrete for patios, walkways and edging strips is easier than indoor projects such as countertops; you don’t have to be so concerned with getting the base of your mold perfectly flat. Your big worry will be the top edges of your form.
Start building your concrete mold by marking out the perimeter, using lengths of string or spray paint. Dig out the area to a depth of 4 inches for patios and pathways, or two inches deep for smaller projects like stepping stones.
Rebar is a major component of structural concrete construction, but for decorative concrete flooring and countertops, it is not widely used. There are several reasons why. First of all, decorative concrete is made up of relatively thin slabs and putting rebar in them can cause cracking. If positioned close to the slab surface, rebar will rust due to moisture absorption, and rust corroded rebar can cause concrete to crack, particularly thinner concrete and concrete not made with gravel. Finally, rebar can also cause ghosting in thin slabs, unsightly white lines that are visible on the slab surface.