![](1.jpg)
Aggregate is a general term that basically refers to small pieces of rock, including sand, gravel and crushed rock. It may be the most taken for granted raw material. Much like electricity or water, it permeates our lives, but our conscious awareness of it is minimal. However, if you take a look around any part of our built world, you will see that it surrounds you. It’s easy to recognize because it looks precisely the same in nature. Sand and gravel are simply sieved and classified, and crushed rock looks just like angular pebbles.