LIME INTRO Flashcards
Lime (Key Points)
Lime is a cementing material.
One of the oldest and most vital chemicals, used since ancient Roman times.
Commonly used as durable mortar and plaster.
Base material: Limestone (CaCO₃).
Water adds workability and chemically combines during hardening.
Mullaperiyar Dam in Kerala (126 years old) was built using concrete made from limestone and surkhi.
Classification of Binding Materials (Key Points)
Air Binding Material
Gains strength only in air (air setting).
Examples: Gypsum, acid-resistant cement, quick lime.
Hydraulic Binding Material
Gains strength in both air and water (hydraulic setting).
Examples: Portland cement, hydraulic lime.
Autoclave Binding Material
Sets when treated in an autoclave with saturated steam, under 8–12 atmospheres of pressure, and temperatures of 170°C–200°C.
Examples: Lime silica, sand, Portland cement.
White Chalk (Key Points)
Composition: A soft, friable, porous, and permeable sedimentary carbonate rock mainly composed of calcite.
Color: Typically white or light gray.
Origin: Formed from the shells of minute marine organisms like foraminifera, coccoliths, and rhabdoliths.
Lime Production: Pure chalk produces fat lime when processed.
Kankar (Key Points)
Description: A nodular, spongy variety of limestone containing clayey and silicious matter, found widely across India.
Regional Name: Known as “Bichwa” kankar in Punjab and Uttar Pradesh, considered the best quality.
Uses: Extensively used for producing hydraulic lime.
Quality:
Nodules should have a blue-grey fracture.
Must be free of sand grains or mud and broken to pass a 12 mm gauge before calcination.
Kankar Lime: Also called Red Lime, it is obtained by burning kankar.
Uses of Lime (Key Points)
1
Water and Sewage Treatment: Used as a chemical raw material for purification.
Metallurgical Industry: Acts as a flux.
Concrete and Mortar: Serves as a matrix material.
Refractory Material: Used for lining open-hearth furnaces.
Glass Production: An essential ingredient in manufacturing.
Masonry Work: Used for making mortar.
Uses of Lime (Key Points) 3
Plastering: Suitable for walls and ceilings.
Construction Products: Used in making artificial stone, lime-sand bricks, and foam-silicate products.
Soil Stabilization: Improves soil for agriculture.
Whitewashing: Acts as a base coat for distemper.
Mortar Enhancement: Improves mortar properties when mixed with Portland cement.
What is IS 712-1773 related to?
IS 712-1773 pertains to Building Limes.
What does IS 1624-1986 specify?
IS 1624-1986 outlines the method of field testing for building limes.
What is IS 6932-1973 used for?
IS 6932-1973 specifies the method of test for building lime.
What is Lime Putty?
Lime putty is obtained by adding hydrated lime to water, stirring it to a thick paste consistency, and allowing it to mature for about 16 hours (non-hydraulic lime). It must be protected from drying out.
What is Coarse Stuff?
Coarse Stuff is prepared by thoroughly mixing and grinding hydrated lime with sand, adding water, and allowing it to mature for less than 16 hours (hydraulic lime).
