2. The art of building the structures in stones with
any suitable mortar is called stone masonry.
Stone is not easily and cheaply available in all
parts of a country.
They are difficult to handle because of their
heavy weight.
They are costly in construction as they involve
high transportation and dressing charges.
3. Stone is extensively used in construction
industry. Not every stone can give great results
because it depends upon various factors which
assign different properties to stone.
4. Main Characteristics of a Good Building stone
are following:
Appearance & color – Uniform color, darker
shades are preferred. Should be free from clay
holes, bands or spots.
Structure – Not dull in appearance, crystalline
homogenous, close and fine grained is good.
Stratification should not be visible.
Weight – Heavier are compact, less porous and
are good for hydraulic structures.
5. Strength – Generally compressive strength is
needed. Igneous rock stones are stronger.
Hardness– Resistance to abrasion, friction and
wear. Its measured on Moh’s Hardness scale.
Toughness – Withstands impact, vibrations,
moving and dead loads.
Dressing – Uniform texture and softness for
fine surface finish. Important for face work of
public buildings.
6. Porosity and Absorption – Exposed surface
absorbs rain water which forms acids causing
crumbling action. Less porous stones absorb
less fluid hence are more durable.
Seasoning – Hardening and weathering affect
due to evaporation of quarry sap and
formation of crystalline film. 6 to 12 months for
proper seasoning is essential to make the stone
worth using in construction applications.
7. Weathering – Should withstand rains, frost,
wind and all other extremities in weather.
Resistance to fire – If free from calcium
carbonate or oxides of iron, it will show
considerable resistance to fire.
Durability – Compact stones are more durable.
Cost – Should have minimum cost in
quarrying, transportation, dressing and
installation.
8. The process of cutting and converting the
stones to the required shape and size and to
give them a smooth finish is called cutting and
dressing of stones.
9. Scabbling dressing:
The dressing in which irregular
projections of the quarried (extracted) stone are
removed by means of scabbling hammer is
called scabb,ing dressing.
Hammer dressing:
The dressing in which the stones are made
roughly square or rectangular by means of a mason’s
hammer, also known as Waller’s hammer, is called
hammer dressing. When used in a wall, the roughly
finished surfaces are further modified by forming to 5cm
wide margin at the edges of the exposed faces.
