Aggregates are simply any collection of rocks. In the aggregates industry, these
rocks are classified as crushed stone, sand, gravel and slag.
We use aggregates every day.
Streets, bridges, roads and sidewalks are made of concrete or asphalt which is
mostly made up of aggregates combined with a binder that acts like glue. Concrete
is used in foundations and basements for houses. Other buildings sometimes use concrete
throughout their structures.
But did you know that many items you use every day have aggregates in them? Your
toothpaste has aggregates in it. Glass is made from sand, which is an aggregate.
Minerals and aggregates are in plates, dishes, pots and pans, baby powder, household
cleaners, makeup, medicines, paints, pencils, fertilizers, wallboard, and more including
some of the foods you eat! How many times have you heard that your cereal, for instance,
is fortified with vitamins and minerals?
Any object that hasnt been grown had to be mined! Aggregates, minerals and metals
all come from the ground. You can look at objects all around you and know which
were grown and which were mined. If its metal, it was mined. If it is wood, it was
grown. If it is cotton or wool, it was grown. Paper comes from trees, which are
grown. Pencils are grown and mined because wood is grown and graphite is mined.
The ink on this paper came from mining. But what about plastic? Is it grown or mined?
Plastic comes from petroleum products, which are mined.
A widespread but highly variable resource in Indiana that was formed mostly by
glacial actions of large ice sheets and then sorted by running water. Sand can be
used as fill, or more often the coarser parts find use as components of concrete
or asphalt pavement. Sand, a finer granular material, also is important in concrete
and in making mortar and in snow and ice control. Very fine grained sand finds use
in foundries to make molds, and also in sandblasting, glass-making, or even as golf-course
Looking for companies that produce SAND in Indiana? Find them in our Member Directory.
The term gravel applies to a range of particle sizes, rather than a specific
rock or mineral type. Gravel is colored by the rock types present. It is a collection
of rock particles that are at least .08 inches in diameter sizes, but may also include
boulders over 10 inches in diameter. Gravel is loose rock that is often rounded
in shape from being worn by water at some point. Gravel can be used alone as fill,
for gravel roads, or residential driveways. Gravel can also be used as a component
of concrete or asphalt pavement.
Looking for companies that produce GRAVEL in Indiana? Find them in our Member Directory.
Limestone (crushed stone)
Limestone is the primary rock type making up aggregate and is mined throughout
Indiana. It is usually gray rock (but color can vary) consisting of at least 50%
calcite. The texture can be coarse- to very-fine grained. Whole fossils or fossil
fragments are typically present in limestone. Indiana is probably best known for
her dimension building stone. Indiana Limestone (properly named Salem Limestone)
is mined in south-central Indiana but is used all over the United States. Indiana
Limestone has helped construct such iconic buildings as the Empire State Building,
the Pentagon, The Washington National Cathedral, and many venerable official, commercial,
or religious structures.
The more widespread and less uniform limestone in Indiana provide for excellent
crushed aggregate, cement, chemical raw material, and for limited architectural
uses. Aglime is produced by heating crushed stone and is used in agriculture. Check
out the Indiana Aglime Council for more
information on aglime.
Looking for companies that produce CRUSHED STONE in Indiana? Find them in our
Slag is a man-made or synthetic aggregate recycled from the steel-making process.
It is a dark-colored and usually rough-textured rock. Slag makes an excellent aggregate
for certain types of road construction. For example, slag is used as the surface
material at the Indianapolis Motor Speedway because its angular, sharp texture creates
excellent traction and skid resistance.
Looking for companies that produce SLAG in Indiana? Find them in our Member Directory.
Want to learn more about Indianas mineral resources? Check out the
Indiana Geological Survey.