Basalt or granite ballast, coarse gravel or crushed stone used for laying roadbeds for highways or railways, primarily for railway subgrades. It is the crushed stone used to support railway sleepers in the railway transportation system and is a common trackbed structure. Before laying the track, the subgrade is first covered with ballast, which is then compacted, followed by the placement of sleepers and tracks. The use of basalt or granite ballast facilitates easy drainage and easy adjustment of track position. Additionally, as the ballast distributes the weight of trains and tracks over the subgrade, it reduces vibrations and noise caused by train passage, enhancing passenger comfort.

And basalt or granite ballast can simultaneously dissipate vibrations and high heat generated by trains passing by, maintain the gauge of the rails unchanged, prevent derailment accidents, reduce noise, and quickly drain rainwater through the gaps between stones. Moreover, the strong permeability of basalt or granite ballast can prevent weeds from growing on the tracks.