True or False: Pebbles are considered an aggregate in concrete.

Pebbles are indeed considered an aggregate in concrete. The primary purpose of aggregates is to provide bulk and structure to the concrete mix, as well as to reduce the overall cost of the concrete by replacing part of the cement content. Aggregates can be classified into two categories: fine aggregates, like sand, and coarse aggregates, which include gravel and pebbles.

In the context of concrete, the size and type of aggregates can vary, but pebbles fit the definition of coarse aggregate, which typically ranges in size from 4.75 mm to larger sizes. They play a crucial role in influencing the concrete’s strength, durability, and overall performance.

The assertion that pebbles would not be considered as aggregates or that their classification depends on conditions like size or treatment does not align with standard definitions and classifications within concrete technology. Therefore, the correct response is that the statement regarding pebbles being an aggregate is true, reinforcing their importance in concrete composition.