Category: Lime
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POZZOLANIC MATERIALS
Pozzolanic materials are siliceous and aluminous materials, which do not possess any cementitious properties but form cementitious compounds by reacting with lime in the presence of water. It is volcanic ash containing about 80% clay. The use of pozzolanic materials provides the following improvements: Naturally available pozzolanic materials are clay and shale, diatomaceous earth, volcanic…
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Workability Test
An 1:3 lime mortar is made with adequate water. The mortar is thrown on a brick wall by a trovel. The sticking quality is examined. If it sticks well, then its workability is good.
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Plasticity Test
A small quantity of lime is mixed with water and left overnight. The so-formed material is spread like butter on a blotting paper with a knife to test its plasticity. Good lime indicates high plasticity.
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Impurity Test
A known weight of lime is mixed with water in a beaker and the solution is decanted. The residue is dried in the sun for 8 hours, cooled and weighed. Based on the percentage of residue, the quality of lime is decided. Residue of less than 10% indicates that the lime is good, 10–20% indicates…
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Hydrochloric Acid Test
Hydrochloric acid of 50% strength is added to powdered lime kept in a test tube till effervescence ceases. Generally, a teaspoonful of powdered lime of about 10 cc is required. It is kept for 24 hours. The bubbling reaction indicates the presence of lime. The volume of insoluble residue signifies unwanted inert material. Class A…
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FIELD TESTING OF BUILDING LIME
The Bureau of Indian Standards (IS: 1624–1974) provides a number of field tests for building lime, which can be easily conducted in the field. They are discussed below next Lecture=> .
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Chemical Tests
1. Heat Test A piece of dry limestone is weighed and heated on an open fire for a few hours. The limestone disintegrates emitting CO2. Due to the removal of CO2 from the sample, it loses weight. The sample is weighed again. The loss of weight indicates the amount of CO2. From this, the percentage of…
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Physical Tests
Physical tests are based on the texture, appearance, colour and odour of limestone. Limestone showing amorphous textures are suitable for making lime. Chalk and fat lime deposits are white or whitish-brown or grey in colour. Magnesium limestone is distinguished from its heaviness and hardness. Limestone with white, bluish-grey, yellow or brown colours are suitable for…