ask big al

Oh the wonder and mystery of concrete! Keeping a consistent color within concrete project is a challenge. There are many factors that that will affect the color of a concrete piece. This can be especially difficult when trying to match a color swatch. Big Al has had some real head scratchers in the past and the guys at Alpha Stone Concrete have put together a standard operating procedure to address this characteristic of concrete.

Try to eliminate as many variables as you can. The weather and temperature of your materials will have an effect on the look of your piece. Use pigments, cements and aggregates from the same batch or lots. Some aggregates may have dust or organic materials in them that will change the color. Take a look at two bags of portland cement that you purchased from the same vendor on the same day an you may find that the country of origin maybe different.

I am guessing from your question that you used a premixed bag of concrete. Many of these mixes uses a minimum portion of cement recommended for decorative concrete. If you poured them on the same day and used the same form material, the changes can be attributed to inconstancies in mixing or troweling. The thin layer cement paste is usually lighter than the rest of the mix that contains aggregate. Troweling methods can have a big impact on the finished appearance.

Big Al knows from experience that different thicknesses of concrete, even poured fro the same mixer, will have a variation in color. We have a display in the Alpha Stone Concrete show room that has sample from 1 1/2" - 5" thick. You can compare these to our standard samples that are 1" thick and a sample 7/8" backsplash. They are all different, within an acceptable range and beautiful.

yours,
Big Al