Locally-derived & Recycled Materials


Cemstone is a leading supplier of aggregates, including sand, gravel, base material and decorative materials such as clear limestone, river rock, granite, quartz and trap rock.

We deliver consistency and quality by providing the majority of our aggregate from our own close-by locations in Minnesota and Wisconsin. And we subject all products to testing at our own facilities, where we perform various tests from particle size analysis to petrographic examinations to ensure that our aggregates meet and exceed industry standards.

Fly Ash

For every ton of cement manufactured, about 6.5 million BTUs of energy are consumed.  Stated another way, for every ton of cement manufactured, about one ton of carbon dioxide is released. More and more fly ash–a by product of coal fired power plants– is being used as a replacement for cement.

Experts estimate that cement production alone contributes to approximately 7 percent of ALL carbon dioxide emissions from human sources. If all the fly ash generated each year were used in the production of concrete, the reduction of carbon dioxide released would be the equivalent to eliminating 25 percent of the world’s fossil fuel-powered vehicles!

Cemstone is a leader in maximizing the use of fly ash, as it improves concrete quality, strength and performance as well. It’s a win-win for everyone, especially the environment.

Silica Fume

Silica fume is a byproduct of the reduction of high-purity quartz with coke in electric arc furnaces, used to produce silicon and ferrosilicon alloys. This byproduct is used as an addition in Portland cement concretes to improve properties. It has been found that silica fume improves compressive strength, bond strength and abrasion resistance of concrete. The addition of silica fume also reduces the permeability of concrete to chloride ions, which protects concrete's reinforcing steel from corrosion, especially in chloride-rich environments such as those of a parking structure.

Ground Granulated Blast Furnace Slag

Slag is a by-product formed in smelting, welding, and other metallurgical and combustion processes from impurities in the metals or ores being treated. Slag consists mostly of mixed oxides of elements such as silicon, sulfur, phosphorus, and aluminum; ash; and products formed in their reactions with furnace linings and fluxing substances such as limestone.