Suitability of Stones for different construction work

To find the suitability of stones with different construction works following parameters are to be observed before selecting the stones.

1)Appearance and Colour

• Stones which are to be employed for decoration work should be of uniform colour.

• Generally, stones must be free from flaws and clay holes.
• Presence of iron in stones leads to the formation of iron oxide which causes disintegration and disfigures the stone.such stones should not be used.






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Disintegration of stone

2)Grain Fineness

• Fine grains stones are suitable for moulding work.
• crystalline stones are prefer over non-crystalline stone.

3)Porosity and Absorption capacity of stones

• Highly porous stones are unsuitable for building construction because during rain water seeps into the stones pores and causes the damage because of presence of acid that penetrates inside the stone wall with rain water and causes deterioration.

                                  
                                                                  Porous Stone

• Under cold climate conditions,water entering inside may even freeze and cause splitting of stones and mortar joints.

3)Strength and Durability

• Stones that are to be used in construction must be able to handle construction loads;for heavy construction those stones are to be used that have high tensile strength comparatively.
• Durability means stones is compact,homogeneous and free from any material that has highly reactive nature with respect to Hydrochloric acid and Sulphuric acid.

4)Hardness and Toughness

• Stones must be hard and tough so that they may resist wear and tear.

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                                                               Hardness of stones

• Hardness can be tested by scratching with a pen knife which should not be able to produce any impression on hard stone.

Other factors are Cost,Availability and Ease of Dressing.