Uses of limestone

• Limestone


  • A sedimentary rock mainly composed of calcium carbonate
  • One third of the limestone that is extracted is used in the building industry
• Limestone properties


  • Moderately soft rock so it can be cut to shape easily
  • Strong and hard enough to provide structural support
  • Weatherproof and resistant to frost damage
  • Most limestone is not tough enough for high wear areas
  • Pleasing texture and colour, can be polished easy
  • Susceptible to acid rain, cheaper than granite
• What happens when limestone is heated?

  • When heated, limestone decomposes to form calcium oxide
  • Calcium oxide is also know as quicklime
• Mortar


  • Substance used to hold bricks or stones together
  • Lime Mortar = Calcium oxide + sand + water
  • The wet paste soaks into the surface of the bricks and then hardens as the calcium oxide absorbs carbon dioxide. This forms calcium carbonate so the bricks are held together by limestone
  • Lime mortar is not used in modern buildings
• Portland cement


  • Made by heating limestone and clay together in a kiln
  • Easier to use and sets more quickly
• Concrete

  • When stones and rubble are mixed with mortar
  • Very good at resisting squashing or compression
  • Less good at resting tension forces or pulling forces. This can be improved if steel bars are laid in the mix. This is known as reinforced concrete
• Aggregate


  • Describes the small stones in the concrete mix
• How can limestone make glass?

  • Powdered limestone, sand and sodium carbonate are heated together
• Disadvantages of quarrying


  • Blasting can disturb people and wildlife
  • Dust is a nuisance and a health problem
  • Can cause heavy traffic from exporting
  • Scarred landscape
• How are problems from quarrying minimised?

  • Limit blasting to certain times of the day
  • Make sure lorries are covered with tarpaulins to lower amount of dust loss
  • New roads can be built to bypass villages
  • The quarry can be landscaped to make it less of an eyesore