Ballast aggregate, commonly used in railway tracks and construction, typically consists of several important minerals and types of rock. These can include:
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Crushed Stone (Granite, Limestone, Trap Rock):
- Granite is hard and durable, making it a preferred choice.
- Limestone is softer but more abundant and sometimes used where high strength is not the primary requirement.
- Trap Rock, usually basalt or diabase, is also commonly used due to its toughness.
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Gravel:
- Varieties of gravels may also be used if they meet the desired size and durability criteria.
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Quartz:
- Common in many types of rock (like granite), quartz adds hardness and durability to the mix.
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Basalt:
- A dense volcanic rock, basalt provides excellent toughness and is often used in high-stress applications.
These materials are selected based on their ability to resist weathering, provide good drainage, and maintain stability under the weight and vibration of passing trains or construction loads. The choice of material may also depend on local availability and economic factors.
