The gravel contains dust or fines that eventually settle to the bottom to create a solid base. Typically used for driveways and gravel roadways, as well as a base for brick paving and retaining wall projects. 31a crushed Limestone. A finely crushed limestone that is 1/4-3/8 in sizing. Used for walkways, decorative, and permeable pavers. Crushed stone is one of the common fillers for the concrete mix, without which no modern construction of a house or other object can do.This building material has many classifications and is endowed with different characteristics and features, on which the quality of future construction directly depends, and the strength of concrete, and the strength of the foundation.