Characteristics of Good Building Stone
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. 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.
- 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.
- 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.
- 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.