The densities (pounds per square foot, or tons per cubic yard, sometimes called "pounds per foot" or "tons per cube") will also vary according to the season, the saturation levels (dampness) of the piles of medium when you purchase the mediums, the quality of the sieves used to sort the crusher runs, and so forth.
The environmental impact of concrete, its manufacture and applications, are complex.Some effects are harmful; others welcome. Many depend on circumstances. A major component of concrete is cement, which has its own environmental and social impacts and contributes largely to those of concrete.
So getting right to it then, what type of foundation are we going to build for our flagstone patio: sand, cement, or gravel?. Short answer: well it depends. Quarry screenings (if available in your area) are generally best for under the flagstones.
Concrete, usually Portland cement concrete, is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens over time—most frequently a lime-based cement binder, such as Portland cement, but sometimes with other hydraulic cements, such as a calcium aluminate cement.
Jenike & Johanson can help you meet your cement industry needs with retrofitting of bins to alleviate costly material flow problems, implementing new mass flow silos or stockpiles to maximize efficient gravity reclaim, or feeding of alternative fuels to the cement kiln or pre-heater calcination tower.