Question

Difference between w slaked lime and hydrated lime

Answer 1

Answer:

Explanation:

Hydraulic limes (so called because they set under water) are made in the same way as non-hydraulic lime but using different limestone. They are sold as hydrated lime and have an initial set when water is added, followed by hardening while they absorb carbon dioxide. The more hydraulic a lime is the faster it sets and the higher it's final strength, but this means that it is less breathable and flexible. NHL5 is the most hydraulic, then NHL3.5, and NHL2 the least hydraulic lime. They do not perform in the same way as modern cements, nor contain the same damaging components. It should be noted however that limes marked with NHL-Z or just HL on the bag can contain some additions that could be potentially damaging and at worst be not much better than cement. Only use limes marked NHL - these meet the highest British and European standards.

Non-hydraulic lime (CL or DL 70-90) is sold as either hydrated lime or putty lime; they set and harden through drying out and absorbing carbon dioxide from the air. This means they have a very slow set: CO2 is only absorbed when certain conditions are met. They are the softest, most breathable limes available.

Hydrated lime simply means that a controlled amount of water is added to quicklime to make a powder that is more stable and safe to handle. This can be done to hydraulic lime or non-hydraulic lime.

Lime putty can be made from either type of lime, and is made by adding an excess of water to quicklime. Hydraulic lime putty will set underwater within hours or days making them impractical, whereas non-hydraulic lime putty will remain plastic and improve with age.