Benefits of Type S Dolomitic Hydrated Lime

Dolomitic Type S Hydrated lime provides a number of benefits in masonry mortar and stucco formulations. These are:

  1. Fine Particle Size - The sub micron size of Type S hydrated lime has several advantages in masonry mortar.
    • Enhances water retention - Smaller particles tend to attract and adhere to water molecules. This enhances workability.
    • Creates a mechanical lock - The fine particle size of the Type S hydrated lime allows the mortar to penetrate deep into the masonry unit. More intimate contact with the unit enhances bond strength.
    • Improves sand carrying capacity - The large number and fine particle size of Type S hydrate allows for more complete coating of sand particles. Mortar made with Type S hydrate can hold more sand without sacrificing workability.
  2. Cementitious - Hydrated lime enhances strength in mortars.
    • Increased strength with mortar age - Type S hydrated lime reacts with carbon dioxide in the air to return to its initial form - limestone. This reaction takes place slowly over time.
    • Autogenous healing - Hairline cracks can be sealed by the reaction of carbon dioxide and hydrated lime in exposed areas of the crack.
    • Pozzolanic Reaction - Unreacted pozzolans in the cement can chemically combine with the lime to form a cementitious compound.
  3. Particle Shape - The flat hexagonal shape of dolomitic lime particles enhances water retention and workability.
    • Provides lubrication - Similar to a deck of cards, the dolomitic lime particles will slide in one plane while being resistant to flow in the other planes.
    • Aids in mortar adhesion - Mortars must be sticky to help masons work efficiently. Type S lime particles help to provide "body" or stickiness to the mortar.
  4. Color - The bright white color of Type S hydrated lime is beneficial for specific mortar types.
    • White masonry - Hydrated lime is an excellent additive in white masonry systems.
    • Colored masonry - By providing a lighter base color, less pigment is needed in colored masonry systems.