Stone
Stone
Stone have been used for building purpose from the immemorial . Building stones are obtained from rocks occuring in nature. Geologically the rocks are divided into three parts.
1) Igneous rocks
2) Sedimentary rocks
3) metamorphic rocks
1) igneous rocks
Which are of volcanic origin they represent a crystalline glassy or fussed structure. These rocks are hard dense, tough impervious, strong and durable. Stones have obtained from these rocks are granite , basalt trap.
2) sedimentary rocks
Which are formed from sediment through the agency of water , wind or glacier. Usually these rocks have budding structure arranged in layers. Stones obtained are known as sand stone , shale, limestone and laterite.
3) Metamorphic rocks
Which are formed in either of the above two processes but subsequently changed or matamorphised in colour structure and texture due to heat and pressure below earth's crust. The rocks have foliated structure in general. The principal stones obtained are quartzite slate marble and gneisses.
Weathering of rocks
The extent to which the face of a stone resists the actio of weather is known as weathering.
Properties of good building stone
The principal requirements are hardness , toughness, uniformity in texture and colour and compact gained composition stone with uniform colour and texture and generally durable. The surface of freshly broken stone should be bright , clean and sharp. The life of granite stone is taken as 300 years and that of sand stone is 100 years. Life of stone is reduced by frost wind, atmospheric impurities, temperature variation etc.
Following test on stones are conducted for durability.
a) Smith's test
b) Acid test
c) Crushing test
d) Abrasion test
e) Hardness test
f)
Stone have been used for building purpose from the immemorial . Building stones are obtained from rocks occuring in nature. Geologically the rocks are divided into three parts.
1) Igneous rocks
2) Sedimentary rocks
3) metamorphic rocks
1) igneous rocks
Which are of volcanic origin they represent a crystalline glassy or fussed structure. These rocks are hard dense, tough impervious, strong and durable. Stones have obtained from these rocks are granite , basalt trap.
2) sedimentary rocks
Which are formed from sediment through the agency of water , wind or glacier. Usually these rocks have budding structure arranged in layers. Stones obtained are known as sand stone , shale, limestone and laterite.
3) Metamorphic rocks
Which are formed in either of the above two processes but subsequently changed or matamorphised in colour structure and texture due to heat and pressure below earth's crust. The rocks have foliated structure in general. The principal stones obtained are quartzite slate marble and gneisses.
Weathering of rocks
The extent to which the face of a stone resists the actio of weather is known as weathering.
Properties of good building stone
The principal requirements are hardness , toughness, uniformity in texture and colour and compact gained composition stone with uniform colour and texture and generally durable. The surface of freshly broken stone should be bright , clean and sharp. The life of granite stone is taken as 300 years and that of sand stone is 100 years. Life of stone is reduced by frost wind, atmospheric impurities, temperature variation etc.
Following test on stones are conducted for durability.
a) Smith's test
b) Acid test
c) Crushing test
d) Abrasion test
e) Hardness test
f)
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