LIMESTONE PLASTER CRACK

Adding Type S hydrated lime improves the elasticity of the mortar, allowing it to adjust under load, without injuring the bond.Įnhanced workability and improved bonding provide a natural waterproofing capacity to mortars containing Type S hydrated lime.

LIMESTONE PLASTER CRACK

High-cement mortars without hydrated lime are typically too brittle to adjust with the structure and may crack under loading. The hairline cracks expose more Type S lime particles to air, and the recarbonation of these particles then seals the crack. This reaction also enables the mortar to self-heal hairline cracks.

This reaction - known as recarbonation - means the mortar actually grows stronger with age as this air and carbon dioxide reaction is all but stoppable. This reaction with air and carbon dioxide causes the hydrated lime particles to revert back to their natural dry powder carbonate form. Over time, Type S hydrated lime particles exposed to air react with carbon dioxide. This penetration of hydrated lime particles forms a better mechanical lock and stronger mortar-masonry bond. This addition of hydrated lime also aids the speed of application and the productivity of your worksite.įine hydrated lime particles penetrate further into masonry than the coarser cement particles.

The plate-like shape of Type S hydrated lime particles provides both a lubricating effect and an essential ‘stickiness’ (the ability of the mortar to hold onto the masonry to which it is applied) to the mortar.

As a result of this addition of hydrated lime and enhanced water retention, more bricks can be laid before tooling, and the need for retempering is all but eliminated

Fine particles of hydrated lime enhance both water retention and sand-carrying capacity, resulting in a mortar that is easier to trowel and better fills the joints.

It is directly related to the rate of construction, since mortars with poor workability will slow the speed at which a mason is able to work.īoth the fine particle size and the shape of Type S hydrated lime improve mortar workability: Perhaps the most important property for the mason, workability describes how a mortar feels on the trowel and the ease with which it can be applied. When Type S lime is added to mortar, these properties provide the following benefits.

Type S hydrated lime has a potential to recarbonate when exposed to carbon dioxide.Type S hydrated lime has a limited oxide content.Type S hydrated lime has a plate-like particle shape.Type S hydrated lime has a fine particle size.Type S hydrated lime is defined by a number of physical properties including: This article will focus on Type S hydrated lime (also called mason’s lime) and its use in the construction industry, although some novel uses, outside of its traditional use in mortar, will also be noted briefly. Type SA - special air-entraining hydrated lime.Type NA - normal air-entraining hydrated lime.

Today, ASTM Standard C207-18 covers four hydrated limes for masonry purposes: The Pont du Gard aqueduct at Nimes in southern France was built in 18CE with a hydraulic lime mortar and remains waterproof to this day. The Ancient Greeks used a fine lime plaster to create the Parthenon, among other buildings that survive to this day, while its use continued to be widespread through the Roman period. Mohanjo-Daro in the Indus Valley was built using lime mortar about 4000 years ago. Lime has been used in masonry applications for at least 6000 years, when lime mortars were used by the Ancient Egyptians to plaster the pyramids at Giza.

Limestone plaster