Date post: | 21-Mar-2017 |
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REPORT ON BUILDING MATERIAL [ROCK AND STONE]INTRODUCTION OF ROCK AND STONE
CLASSIFICATION OF ROCKS
TEXTURES OF ROCK
USES OF STONE
CHRACTERISTICS OF STONE
TESTS FOR STONE
PRSERVATIVES OF STONE
ARTIFICIAL STONE AND ITS ADVANTAGES
ROCKS AND STONES
INTRODUCTION Rocks is the solid portion of the earth crust and a unit of
building material. Rocks having only one mineral is known as monomineralic rock and those having several minerals as polymineralic rocks.
Quartz, sand, pure gypsum, magnesite are monomineralic rock. Granite , basalt, etc. are polymineralic rocks.
The rocks are named after the predominant mineral present in it.
Stone is obtained fro rock. The rock quarried from quarries is called stone. Quarried stone may be in the form of stone block s, aggregate, stone slabs, stone lintels, stone flags, etc. Stone has to be properly dressed before it is used at the place of its use.
CLASSIFICATION OF ROCKSGeological classification
Physical classification
Chemical classification
Classification based on hardness of stone
GEOLOGICAL CLASSIFICATION
Igneous rocks
Sedimentary rocks
Metamorphic rocks
IGNEOUS ROCKS
Depending upon the cooling effect different types of igneous rocks are formed.
Volcanic igneous rocks- extremely fined grained ex. Basalt
Hypa- byssal rocks-fine grained and crystalline ex. Dolerite
Plutonic rocks – coarse grained and crystalline ex. granite
Igneous rocks Igneous rocks - [ primary,
unstratified , eruptive, It is cooled down molten lava , also known as magma. These rocks form deep inside the core of earth where they continuously face extremely high temperature when near the core. They are in molten form but convert to solid when present in relatively cooler regions-. Final form of rock is solidified form of magma– granite and basalt. Igneous rocks contains minerals like augite, felspar, horne blende, mica , quartz etc.
Sedimentary rocks Sedimentary rocks – [ aqueous
stratified ] , gradually deposited disintegrated rocks. These rocks take years to sediment in form of layers over layers surface of earth is subjected to various chemical agent which are brought by rain frost and various other weather conditions. These agents breakup the surface which is carried away by further rains to rivers and other water channels in which they continue to travel . As the velocity of the river decreases , matter starts depositing in the form of debris and form the rock . Ex. – sand stone, limestone
Metamorphic rocks-Metamorphic rocks- One to
change in structures of earth, igneous and sedimentary rocks find their way to high temperature zones inside the core. Continuous exposure to high temperature and pressure change either the mineral composition or texture and at times both to produce an entirely new form , is called metamorphic rock. EX. Granite changes to gneisses lime stone to marble, shale to stale.
METAMORPHISMMetamorphism is a process in
which re- alignment of minerals change the texture of rocks.
There are four types of metamorphism.
Plutonic metamorphismCataclastic metamorphismThermal metamorphismDynamo- Thermal
metamorphismAs a result of metamorphism ,
lime stone and marl become marble, basalt and trap are converted to schist, late rite and granite become gneiss.
PHYSICAL CLASSIFICATION OF ROCKSStratified rocks are such
rocks which possess planes of stratification or cleavage. These rocks can be easily split along these plane.
Unstratified rocks have compact granular structure and don’t show any layers of stratification or cleavage Ex. All rocks of volcanic origin.
Foliated or laminated rocks comprise of thin lamination. They can be split in definite direction and size. Ex. Metamorphic rocks .
CHEMICAL CLASSIFICATION OF ROCKSSiliceous rocks consists of silica
as their predominant constituent. These are very hard and durable not easily effected by weathering agencies. Ex. Granite, trap, basalt, sand stone, quartzite.
Argillaceous rocks: T he predominant constituent is clay. Alumina which is actually clay , remains mixed up in varying proportion with siliceous, calcareous and carboneous matter. These are hard, brittle, durable and dense in nature. Ex. Late rite, slate, porphyry.
Calcareous rocks : The predominant constituent is calcium carbonate. Ex. Lime stone, marble, dolomite, kankar.
CLASSIFICATION BASED UPON HARDNESS OF THE STONEVery hard
stone :diamond, gravel, quartzite , taconite.
Hard rocks : granite basalt, trap
Medium stone : dolomite, limestone
Soft stone: talc, gypsum, slate, sandstone
Hardness may determine what a stone may be used for jewellery, carving, faceting, handling, or storage etc.
TEXTURE OF ROCKS The way the particles of rocks forming minerals are
arranged in the rocks is termed as texture or structure of the rock.
Compact crystalline : Very fine grains tightly held together . Quartzite, marble etc. Granular crystalline : Similar size particles and all are held together in such a way ,
that all the grains are separately recognizable. Sand stone, gneiss, etc. Conglomerate: Rounded grains of different sizes which remain held together by
some cementing material. Glass texture : Any grain or crystal at the fractured surface is just like a glass. Foliated texture: All the grains arranged in the form of parallel layers. Porous granular : This texture is just like granular crystalline but small perforations
can be easily noticed at the fractured surface of the stone. Vesicular texture : Small irregular depressions or cavities on the fractured surface. Porphyritic texture : Crystals of some minerals are larger than other crystals other
rock forming materials, can be easily recognized. Pisolitic texture : Large size grains of peas size , uniformly distributed at the
fractured surface.
USES OF STONEFor masonry workLintel and vertical columnCovering floors of building Paving of roads and foot pathConstruction of roads in form of boulders and aggregateAs an aggregate in cement as well as lime concretesBase material for water works and sewage treatment
plantsAs stone patties for roofingManufacture of cement and lime Stone may be used to give massive and pleasing
appearance to the building.
CHRACTERISTICS OF STONES General structure: It may be stratified, unstratified or foliated. Fineness of grains Compactness Durability: It depends on its chemical composition, physical structure, homogeneity
and closeness of grains and type of cementing material. Strength Hardness Weight Percentage of wear: It is measured by attrition test and should not be more than 3%. Easy in dressing or working Appearance Porosity and absorption: Less porous are considered good stones and absorption by
weight after 24 hours should not be exceed 0.60. Resistance of fire Weathering: Various atmospheric and external agencies such as Rain, frost, wind etc,
is termed as weathering. Toughness: It is determined by impact test and represented by toughness index.
Toughness index should not be above 19 and below 13.
Tests for stonesFor any specific use , following tests can be carried out
on stonesSmith’s testFreezing and thawing testFrost action testAcid testWater absorption testMicroscopic examinationImpact testAttrition testCrushing testCrystallization testHardness test
Preservation of stonePreservation of stone required when ether stone is
poor quality or aggressive atmosphere etc. There are so many types of preservatives to protect stone.
PaintsLinseed oilCoal tarParaffinAlum and soapUse of baryta or barium hydroxidePointing and plastering
ARTIFICIAL STONEArtificial stone consists of 1.5 parts of coarse aggregate of size
3mm to 6mm and 1.5 parts of fine aggregate of size less than 3mm.
Both aggregate are obtained from natural stone. Both aggregate mix well and will form three parts.
Add one part of cement to three parts mix them dry.Add suitable pigment to the dry mix. Lastly add water to the dry mix to obtain a mixture of workable
consistency.The plastic mix is then pressed into moulds, cured, and dried.Now Artificial stone blocks are ready to use. Blocks may be
polished or white cement can be used to develop light shades. Cement, concrete, mosaic tiles, terrazzo, R.C.C. are some
examples of artificial stones.
ADVANTAGES OF ARTIFICIAL STONESCan be cast in any shape or size.Can be made stronger than natural stones.Can be used in any position.Easily moulded and seasoned at the site of work.Do not require any dressing.Can be designed for any strength.Can be cast in economical sizes which could be easily handled.More durable than natural stones.Do not require any transportation as they can be cast at site.Holes , for the purpose of pipe or electric wire fittings, may be
kept at the time of casting.The progress of work will be faster with precast stone .
THANKYOU
MANISHA AGARWAL