What is the coarse aggregate of concrete

Exposed aggregate concrete can almost be compared to a piece of granite or marble transformed by polishing: A plain, unremarkable surface has been stripped away to reveal the exceptional beauty lying beneath. In the case of concrete, that beauty is in the form of decorative aggregate, either natural or manufactured.

The decorative process of exposing aggregate has been around since the early 1900s, well before pattern stamping, stenciling, and decorative overlays became trendy. But this method is far from being ready for retirement. An exposed aggregate finish offers numerous advantages. And many of today's contractors are finding creative ways to take exposed aggregate to a new level.

What Is Exposed Aggregate and Where Is it Used?

An exposed-aggregate surface is obtained by placing concrete and then removing the outer 'skin' of cement paste to uncover decorative coarse aggregate (either batched into the concrete mix or seeded onto the surface). Because of its durability and skid resistance, an exposed aggregate finish is ideal for most flatwork including:

  • Sidewalks
  • Driveways
  • Patios
  • Pool decks
  • Plazas

An exposed-aggregate finish is also possible on concrete walls or tilt-up panels. Vertical applications include:

  • Decorative retaining walls
  • Architectural building facades
  • Sound barrier walls