Aggregates can be used for many different projects within the construction sector. These include crushed rock, sand and gravel, stone and fill materials. These are mainly used in construction projects. In concrete, an aggregate is used for its economy factor, to reduce any cracks and most importantly to provide strength to the structure. In roads and railway ballast, it is used to help distribute the load and assist in ground water running off the road. Aggregate is an essential part of making concrete and is used for many different reasons. The benefits include; reduction of cracking, improve the structure, and help with water drainage. Aggregate is used as Industrial Raw Materials with other industrial raw material products such as Silica Flour, Limestone, Calcium Carbonate, Quicklime, Talc, Volcanic Rock and Abrasives. Natural aggregates (crushed stone, sand and gravel) and industrial minerals are among the most abundant natural resources and a major basic raw material used by construction, agriculture, and industries employing complex chemical and metallurgical processes.
If the size of the aggregates used is small, there is a requirement for more binding material which increases the cost. Conversely, more aggregate use will result in a wastage of the binding material. The aggregate industry commonly refers to four general groups of crushed stone: limestone, granite, traprock, and sandstone. Industry usage of these terms is only loosely tied to common petrologic classifications. Limestone may refer to any carbonate rock including limestone, dolomite, and marble. Granite refers to coarse-grained igneous or metamorphic rocks including true granite as well as other light-colored rocks such as syenite, gneiss, and the dark-colored gabbro. Traprock is dark-colored, fine-grained volcanic rock including basalt and diabase. Light-colored, fine-grained volcanic rock may be called either granite or traprock by different producers. Sandstone may refer to sandstone, conglomerate, breccia, and metamorphic quartzite. Limestone makes up about 71% of crushed stone production.