Aggregate is the word used to describe sand, rocks, gravel, crushed stone and shale that are used in construction.

Aggregate is used virtually everywhere – in all buildings and infrastructure, including homes, roads, schools and hospitals. Without aggregate, we could not build these essential parts of our modern world.

Here is everything you ever wanted to know about ... AGGREGATE!


  • Aggregate is the most-mined material in the world.
  • People have used sand and stone for foundations for thousands of years but it was the Romans who refined the production and use of aggregate when they used it to build their vast network of roads and aqueducts. The invention of concrete created an immediate, permanent demand for construction aggregates. Today, everything built with concrete contains aggregate, including homes, roads, schools and hospitals.
  • It takes a lot of rock to build a road! In fact, it takes 18,000 tons of rock aggregate to build one kilometre of road. That’s enough to fill four Olympic-sized swimming pools.
  • Each person uses 10 to 15 tonnes of aggregate each year. That’s one tandem truckload per Nova Scotian. For example, building a single family requires about 160 tonnes of gravel (about 11 truckloads). Building a school or hospital requires about 15,000 tonnes of aggregate.
  • We need to extract 10-15 million tonnes of new aggregate each year to build and maintain Nova Scotia’s infrastructure.
  • Aggregate quarries and pits only use about 0.11% of Nova Scotia’s landmass. That is a tiny amount of land compared to the huge contribution aggregates make to our lives.
  • Aggregate makes up about 80% of concrete and about 94% of asphalt.
  • Point Pleasant Park, one of Nova Scotia’s most beautiful natural spaces, contains over 50 former quarries that provided stone to build forts and walls in the park. For example, slate from the Quarry Pond was used to help build the Prince of Wales Tower, which is the oldest Martello tower in North America.
  • Ever notice that some roads and highways are red? The color is determined by the aggregate used to build them. Most roads are black or grey because most rock aggregate is black or grey. Rock from quarries like this one in Kemptown, Nova Scotia, gives roads a reddish color..

  • Building one kilometre of two-way highway requires about 18,000 tonnes of aggregates.
  • Disney World was built on Nova Scotia rock. Aggregate from Nova Scotia was used as fill at Disney World in Orlando, Florida, and to help make the highways that bring millions of people to Orlando each year. Nova Scotia’s easy access to shipping by sea, and close proximity to the United States, makes us an important supplier to the US construction industry.
  • Asphalt and concrete are recyclable. When paving crews dig up old roads and highways, they often save the asphalt so it can be crushed, mixed with other aggregate and used again as aggregate in new pavement. This reduces our environmental impact by diverting waste from landfill and reducing the amount of quarrying we need to do for new aggregate.
  • Hourglasses, or sand clocks, measure time by the descent of sand from one glass bulb to another. According to the Guinness Book of World Records, the first hourglass was invented by a French monk called Liutprand in the 8th century AD. Hourglasses first appeared in European ship inventories from the 14th century. The hourglass was ideal for ocean travel because the bobbing waves didn’t affect its accuracy.

  • Building one kilometre of two-way highway requires about 18,000 tonnes of aggregates.