Types of stones and their applications.pdf

Types of stones

1. Building Stones-II

2. Some common building Stones
•Igneous rocks by virtue of their texture and
minerals present in them have the ability to
take very good polish and thus are become
increasingly popular for face work .

3. Granite
Granite
•Graniteisaplutonicigneousrockbecauseitis
formedduetosolidificationofmagmaat
greaterdepth.Itisholocrystallineandleucocratic
rockbecauseitiscompletecrystallineandlight
coloredrock.
Mineralspresentingranite
•Graniteiscomposedofonlyprimaryminerals.
Amongthese,feldsparandquartzoccuras
essentialmineralsandcommonaccessory
mineralsaresuchashornblende,biotitic.

4. Granite

5. Granite
Structure
•Graniteiscompact,dense,massiveandhard
rock.Butmuraljointsoccurinsome,dividingthe
rockintonumberofrectangularblocks,
therebyfacilitatingthequarryingprocesses.
Texture
•Granitestypicallyexhibitaninterlocking,
coarsegrainedtexture.Granitesareusually
equigranular.Butsomeshowsinequigranular,
texturesandarecalledgraniteporphyries.

6. Granite
AppearanceofGranite
•Graniteisgenerallymediumtocoarse
grainedandgrayishorpinkishincolor.
ModeofOccurrenceandrelativeabundance
•Graniterockoccurintheformofverylarge
igneousbodiessuchasbatholiths,stocks,
oftentheyoccurascoresofmountains
rangesandarethusrelatedtomountain-
buildingactivity.

7. Granite

8. Granite
PhysicalpropertiesofGranite
•Graniteismassive,unstratifiedanddense,
thereforeitisverystrongandcompetent
•Granitehasaninterlockingtexture,whichkeeps
mineralsfirmlyheldandthiscohesioncontributes
greaterstrength.
•Graniteiseitherequigranularorhasporphyritic
texture.
•Sincegraniteismassiveandformedfrommeltit
isneitherporousnorpermeable.Sono
saturationorpercolationbywaterispossible.

9. Physical properties of Granite

10. Physical properties of Granite
•Graniteisveryrichinsilica;thereforeitisvery
muchresistanttodecay
•Presenceofmuraljointpermiteasyquarrying
•Presenceofriftandgrainpermiteasydressing.
•Graniteshavetheabilitytotakesuperbpolish,and
hencearebecomingincreasinglypopularforface
worksofconstruction.
•Granitesofferreasonablefireandfrostresistance,
becausemineralsarenotmanyandtheserocksare
freefromfractures.

11. Basalt
Basalt
•Thetermbasaltwasfirstusedbyplinytoreferablack,
ferruginousrock.Nowthetermisappliedtoveryfine
grained,blackvolcanicrockinwhichplagioclasefeldspar
andmaficmineralsoccurapproximatelyinequalamounts.
Minerals
•BasaltisasimplemixtureofLabradorite,augite(essential)
andironoxide.Itissimilartodoleriteinmineralcontent.
Biotiticandhornblendesaretheotherrareaccessoryminerals.
Structureandtexture
•Vesicularandamygdalstructuresarethemostcommonin
basalt.Columnarstructuresandflowstructurearealso
observedinsomecases.

12. Basalts

13. Basalts
AvailabilityandmodeofOccurrence
•Basaltsarethemostabundantamongvolcanicrocks.Their
quantityisfivetimesgreaterthanallothervolcanicrocksput
together.Theyoccurasflatorslightlyinclinedlavaflow.
PropertiesandUses
Massivebasaltsarehighlydurableandthestrongest.Thisis
becausenotonlytheyarecompact,hardandtoughbutalso
morefinegrainedthandolerite.Forthisreasonbasaltsare
extensivelyusedasbuildingstones.
Asaroadmetal,thebasaltsareexcellentformacadamand
bitumenroads.Theyarehard,toughandwear-resisting
andhavegoodbindingproperties.

14. Limestone
Limestone
•Amongthesedimentaryrocks,intheorderof
abundance,limestonerankthird,nexttoshales
andsandstones.Thesecomprises5%ofall
sedimentaryrocksoccurringontheearth’s
surface.
•Limestonearetypicallynon-detritalrocks.They
areformedeitherchemically,duetoprecipitation
ofcalciumcarbonatefromsurfacewater.Or
organically,duetoaccumulationofhardpart
oforganisms

15. Limestone

16. Limestone
•Inhandspecimens,limestonesshowdifferent
colorslikewhite,gray,buff,yellowandblack.
•Ifthelimestonehaveformedoutofchemical
precipitation,theyareextremelyfinegrained.
Incaseoforganic,limestonehaveformedout
ofchemicalprecipitation,theyareextremely
finegrained.Incaseoforganic,limestone,the
grainsizemayvarydependingonthetypeof
organismsresponsibleforitsformation.

17. Limestone

18. Limestone
Typesoflimestones
•Massivecompactfinegrainedlimestoneswith
greyoranyotherlightcolorarecommonin
naturetheporoustypesareyellowish,brownish
etc.
•Theotherimportanttypesare
•Chalk,stalactites,stalagmitesanddripstones,
travertine,kankar,fossiliferousorshell
limestone,flaggylimestone,lithographic
limestone,magnesiumlimestone,argillaceous
limestone,siliceouslimestone.

19. Limestone

20. Limestone
Porosityandpermeability
•Limestonesarethemostdeceptiveandmost
unpredictablerocksintermsofporosityand
permeability.Thisisbecauseoftheinherentcharacter
oflimestone,thatisgettingcorrodedbycarbon
dioxide,bearingwateratanytime.Butinsidethey
mayhavesolutioncavitiesandsolutionchannelsof
varyingmagnitudes.Highlyirregularanduneven
topographyformedthiswayinlimestoneregionis
knownasKarsttopography.
•Thustherangeofporosityandpermeabilityis
unreasonablelargeinlimestone.Thereforetheyare
eitheroneofthebestorworstaquiferinnature.

21. Limestone
CivilEngineeringandOtherUses
•Massiveandcompactlimestonesare
reasonablecompetenttosupportcivil
engineeringstructures.Theyaresuitableas
roadmetal,railwayballastandasconstruction
materialbutmaynotbeverydurable.
Furtherifhollow,theirload-bearing
strengthalsowillgetreduced.

22. Limestone

23. Marble
•Thetermmarbleisderivedfrommarmore“a
shiningstone”.Likequartzite,marbleisalsoa
parametamorphicrock.Itisacalcareous
metamorphicrockformedoutofthethermal
metamorphismoflimestone.Thoughitisnot
veryhardorstrongitisthemostvaluablerock
occurringinnature.Itsvalueisduetoitspleasant
color,goodappearance,easyworkability,
charmingtranslucencyandtheavailabilityto
takebrilliantpolish.Itisalsovaluablebecauseit
isnotabundantlyavailableinnature.

24. Marble

25. Marble
•Marbleshowsthefollowingproperties
•Color:Somemarblesshowuniformcolor
throughouttherock.Puremarbleismilky
whiteincolor.Pleasantshadesofgreen,yellow,
brown,blueorgreycolormayalsooccur.
•GrainSize:Finemediumorcoarsegrained,but
therockisequigranular.
•Textureandstructure:Marbleshowsatypical
granulosestructure.Thisisbecausecalcite,
whichisneitherplatynorprismatic,isthemost
predominantmineraloftherock.

26. Marble

27. Marble
•Hardness:Marbleisrelativelysoftandiseasilyscratched
withaglasspieceorpenknife.Forthisreason,marblecanbe
convenientlycutmechanically.
•Appearance:Whenahandspecimenofpolishedmarbleis
turnedaround,atwinklingappearanceisnoticedbecause
thesurfaceoftherockpassesthroughcleavageplanes,itis
reflectedgivingatwinklingappearance.
•Translucency:Purewhitemarblearereasonably
translucent,whichisanadditionalvirtueofmarble.
•MineralPresent:Justasquartzisthemostpredominant
mineralconstituentofquartzite,soiscalciteinmarble.

28. Marble

29. Properties and Uses of Civil
Engineering Importance
•Occurance:Asageologicalformation,marbleisfoundin
theformofthickorthinbedsinassociationwithother
metamorphicrockslikegneiss,schistsandslate.
•‘asalreadymentioned,marblesarewellknownfortheir
beautifulcolors,pleasingappearanceandeasy
workability.Beingdenserandlessporous,itisofcourse,
strongerthanlimestone.Marblesoccurringinnatureare
quarried,dressedandusedasbuildingstonesfor
templesorotherconstruction.Marblesprovideaesthetic
beautyandapleasingappearancetotheconstruction.They
areusedininnumerableornamental,decorativeand
monumentalworkswherecarving,engravingand
polishingetcareinvolved.

30. Marble

31. Sandstones
Sandstones
•Amongsedimentaryrocks,sandstonesare
veryabundantandarenextonlytoshalesin
thisrespect,theyrepresentnearly15%of
thesedimentaryrocksoftheearth’scrust.
Theseareverycommonclasticrocksmadeup
ofsandandaredescribedasarenaceousrocks.
Unlikeconglomerates,sandstonesare
stratifiedandsometimesfossiliferoustoo.

32. Sandstones

33. Sandstones
•Sandgrainsinsandstonearemostlyquartz,In
additiontothesetheothermineralsaremica,magnetite
andfeldspar.
•NatureofSandGrainsandCementingMaterials
•Basedonthesizeofsandgrainsthesandstonesmaybe
coarsegrained,mediumgrainedorfinegrained.But
generallythesandgraininanysandstoneswillbe
nearlyofthesamesize.
•Thesandgrainpresentmayberoundedorsurrounded
orangularinshape.
•Sandstonesoccurindifferentcolorssuchaswhite,red,
yellowgreyandgreen.Thecolorofsandgrainisdue
tocementingmaterial.

34. Sandstones

35. Sandstones
PorosityPermeabilityandUses
•Byvirtueoftheirmodeofformation,like
conglomerates,sandstonesalsogenerally
porousandpermeable.Theporosityof
sandstonesisdependentonthesizeandshape
ofthesand,Furtherthedegreeofcementing
alsocontributetotheporosity.Therefore
sandstonesvaryconsiderableintheirporosity
andpermeability.

36. Sandstones
•Fromthecivilengineeringpointofview,
however,carefulstudyisnecessarybefore
consideringarockascompetentorincompetent,
usefuloruseless.Whensandstoneis
considerablyporousandpermeablei.e..when
thedegreeofcementationisless,itwillnot
makeupagoodrock.&ifthesandstonearewell
cementedandifthegrainsareangularandquartz
incomposition,thesiliceoussandstonearethe
bestandhighlysatisfactoryforallcivil
engineeringpurpose.

37. Sandstones

38. Gneiss
Gneiss
•Amongdifferentmetamorphicrocks,gneissis
morewidespreadandabundantthanothers.
•Gneissisageneralnamegiventoany
metamorphicrockwhichshowsagneissose
structure.Inmanycases,gneissesarederived
fromgranites.Hence,themineralscomposition,
grainsize,color,etc,willbemoreorless
similarbothingraniteandgneisses.Forthis
reason,itiscommonlyreferredtoasgranite
gneiss.

39. Gneiss

40. Gneiss
•Afewdetailsofitsphysicaldescriptionareasfollows
•Diagnosticcharacter:FoliationPresent
•Color:differentshadesofgrayandpink,butgenerally
palecolored.
•Grainsize:Mediumtocoarsegrained
•Textureandstructure:Generallyequigranular,but
sometimesporphyroblastic.Foliationi.e..alignment
ofmineralsischaracteristicallyseen.
•MineralsPresent:Feldsparandquartzusuallymake
upthebulkofagneiss.

41. Gneiss

42. Gneiss
Origin
•Gneissesareusuallyformedoutof
dynamothermalmetamorphismofgranite,
sandstonesandconglomerates,etc.Among
these,granitegneissisfarmoreabundantthan
allothers.
Occurrence
•Duetoclosemineralogicalandother
resemblance,granitegneissesmaybetreatedas
varietiesofgranitesthemselves.

43. Gneiss
•Asgneissisasilica-richrock,itisdurable
•Byvirtueofmineralogicalsimilaritytogranite,
gneissesalsohavepleasingcolor
•Gneissisreasonablynon-porousandimpermeable,
contributingtoitsstrength.
•Thegneissosestructurewithitsalternatingbandsof
contrastingcolorsonpolishing,producesaverygood
appearance.
•Thefoliation,tosomeextent,improvesthe
workabilityofgneiss.
•Theoccurrenceofgneissinplenty,inmanyplaces,
makesitanimportantbuildingstoneormaterial

44. Gneiss

45. Laterite
•ItisaSedimentaryrockcomposedofmostlyofoxidesofaluminium
withvaryingamountsofoxideofiron.
•TextureandStructure
•Therockisformedfromchemicaldecompositionofalkalineigneous
rocksbyleachingofsomecomponents.ThisresultsinSpongystructure
andporoustexture.
•BuildingProperties
•TheLateritesarelighttodarkredincolordependinguponthe
quantityofironoxideintheircomposition.Theyarepoorin
compressivestrength,whichvariesfrom20-30kg/cm
2
.
•Lateriteareusedonlyinordinaryconstructionandmostlyasroadmetal
ratherthanbuildingstone.
•IndianOccurrence
•LatteritearefoundinMaharashtra,MadhyaPradesh,Bihar,Orissa,
andalsoinsomesouthernstateslikeAndhraPradesh,Madras,andKerala.

46. Laterite

47. Slate
•Slateisadense,finegrained,argillaceous,
parametamorphicrock.Ithastheunique
characterofslatycleavage.Itisformedoutof
dynamicorregionalmetamorphismofshale.By
virtueofitscleavagecharacter.Itisformedout
ofdynamicorregionalmetamorphismofshale.
Byvirtueofitscleavagecharacter,itsplitseasily
intoverythinsheetsorslabsofconsiderablesize.
Extremefinegrainedsize,absenceofreaction
withacid,slatycleavageandshiningonsurfaces
arediagnosticcharacterofslate.

48. Slate

49. Slate
•Physicalpropertiesofslateareasfollows
•Color:Slateusuallyexhibituniformcolor.Generally,
theyareblackordarkgrayishblack.Butothercolors
likebrown,red,greenandgreyandyellowoccurs.
•GrainSize:Slateisverydenselookingandextremely
finegrained.Individualgrainsaretoofinetobeseen
fromthenakedeye.
•Texture:Foliationisclearlyvisiblethroughconstituent
mineralsarefineandunrecognizable.Thelayersof
shalewhicharedifferentlycoloredappearasribbonsor
bandsinslatyformationinfields.

50. Slate

51. Slate
•Beddingandfossilcontent:Someslateretain
theirbeddingorlaminationcharacterofshale
asarelictfeature.Fossilmayoccurrarelybut
suchfossilareoftendistortedandsqueezedoutof
theiroriginalshape.
•Hardness:Slatesarerelativelysoftwhen
comparedwithothermetamorphicrocks.
•MineralsPresent:Slatesaremainlymadeupof
secondarymicaandquartzotherminerals
whichmayoccurarebiotite,talc,feldsparetc.

52. Slate

53. Slate
Origin
•Themajorityofslatesaretheresultofdynamic
metamorphismofargillaceoussediments.A
fewslatesmayalsobeformedfromaltered
basicigneousrocks.

54. Properties and Uses of Civil
Engineering Importance
•Slatesaredense,finegrained,impermeableand
relativelyresistanttodecay.However,since
slatesaresoftandincompetent,theycannot
withstandgreatloads.Sotheyarenotsuitable
forfoundationpurposes.Duetocleavage
characterandsoftness,theyspliteasily.Hence
theycannotbeusedasbuildingstone.Butsince
slatesareimpermeableandcanbesplitintothin
butbigslabofuniformthickness,theycanbe
convenientlyusedforroofing,flooring,mantle
andshinglesetc.theycanalsobeusedas
shelves.

55. Slate

56. Qualities Required In Stones
1.Strength
•Forordinarytypesofstone-houses,any
goodrockbeingtraditionallyusedforthe
samepurposewillnormallypossess
sufficientstrengthtobearusualloads.But
engineermustsatisfyhimselfaboutallthe
strengthparametersonlyafterthroughtesting
inaccordanceofcodes.

57. Qualities Required In Stones
•CompressiveStrength
•Itisthemainqualityofabuildingstone
expressedasthemaximumloadperunitarea
atwhichthestonestartsbreaking.
•Thispropertycanbeeasilytestedinacivil
engineeringlaboratoryontheUniversal
TestingMachine(U.T.M)
•Thecompressivestrengthofmostcommonly
usedstoneshasbeenfoundtobe280–2800
kg/cm
2

58. Qualities Required In Stones
TraverseStrength
•Itistheresistanceofferedtoabending
loads.Inthecaseofbuildingstonesitisto
beevaluatedonlywhenthestoneistobe
usedasabeamorlintel.Thispropertyis
commonlydeterminedasmodulusofruptureR
theRvalueforvariousstonesvarybetween
20–300kg/cm
2

59. Qualities Required In Stones
ShearStrength
•Stonesofgoodqualityareoftenusedas
piersandcolumns,especiallyin
monumentalbuildings.InSuchSituations,
thestoneistowithstandsheartypeofloads.
Henceitmustpossessufficientstrength.
•Theshearstrengthofcommonbuildings
stonesliesbetween70–160kg/cm
2

60. Qualities Required In Stones
2.Hardness
•“Hardnessofstonemaybedefinedasitscapacityto
resistscratchingorabrasion”
•Thehardnessofstonesdependonmineral
composition.Thesignificanceofthispropertyliesin
itsresistancetowearandtearduringitsusein
whererubbingactionduetonaturalagenciesorby
artificialcausessuchasinflooringisinvolvedthus
stonesfacingtheprevalentsandladenwindsinanarea
shouldbechosenwithgreatcareassoftstonesmaybe
wornoutmosteasilyandquicklythenexpected.

61. Qualities Required In Stones
3.Toughness
•Isapropertyrelatedtobothhardnessand
strength.Itisdefinedasthecapacityof
stonestowithstandtheimpactloads.
•Thusstonestobeusedinfoundationsunder
heavymachineswhenvibrationmaybea
commonphenomenonmaynotonlybehard
andstrongbutverytoughalso.

62. Qualities Required In Stones
4.WaterAbsorption
•BuildingStonesareliabletocomeincontact
withwaterusedinfoundationandexterior
walls.Ideally,theymustnotabsorbmoisture
becausecanbecomecauseofmanytroubles.
Waterabsorptionmaybedefinedas‘Quantityof
waterabsorbedbyastonetillsaturation’water
absorptionisespeciallysignificantwhenastone
isusedinfoundationsincoldclimatewhere
freezingtemperatureisacommonphenomenon.

63. Qualities Required In Stones
•Insuchsituationswaterwithintheporesmay
freezeandexertsdisintegratingstresses.
Disintegrationofstonesbyfreezingwateris
knownasfrostaction.Andthisprocessmay
spoilporousstonesusedonoutersurfaceor
ascostlybuildingsunlesstheyareprotected
fromrains.

64. Qualities Required In Stones
5.Appearance
•Stonesareavailableinalmostallcolorsfrommilk
whitetobloodredtopitchblack.Naturally,
appearanceofastoneforabuildingbecomesan
importantfactorforselection.
•Tajmahalatagrawasconstructedwithwhitemarble
althoughredandgreenorpinkmarbleareavailable.
ForredfortinDelhi,theredcolorsandstonewasused
toindicateroyalty.
•Aestheticallylightcolorarepreferredintheexterior
ofthebuilding.Appearancehavenosignificance
whenthestoneisusedinobscurepositionssuchas
infoundations.

65. Qualities Required In Stones
6.Workability
•Stoneswhenobtainedfromtheirnaturalplaceof
occurrence-theoutcropsarequiteirregular
masses.Theyrequirealotofworkonthembefore
theycanbeconvertedtoappropriateshapesforused
inconstruction.Shapesrequiredmayvaryfrom
ordinaryrectangletosquareblockofsmallsizes.
Theprocessofgivingapropershapedimension
andsurfacefinishtoarawstonebeforeitisfitfor
useinconstructioniscalleddressing.

66. Qualities Required In Stones
•Ithasbeenobservedthatallthestonescannot
bedressedorworkedeasily.Thecostof
dressingstonesperblockmaybecomean
importantfactorinselectionofstones.
•Igneousrockslikebasaltandgranitesare
verydifficulttodressandpolish.Marble
andlimestonehoweverarecomparatively
softandcanbegivenanyshape,finishand
polishatcomparativelylowcost.

67. Qualities required in Stones
6.Durability
•Itdenotestheperiodinyearsforwhichastone
maystandpracticallyunalteredafterbeing
usedinconstruction,
•Adurablestonemust
•Withstandload
•Mustkeeptheoriginalappearance
•Mustresisttheeffectofcoldandheat
•Mustnotsufferdeteriorationanddecompositionby
gasesandsurroundingindustries.

68. Qualities required in Stones
•Obviouslythedurabilityofstonedoesnotdependon
asinglepropertybutratherasetofproperties
discussedabove.
Itmaybesummarizedthatastonewillbedurablewhen:
•Ithashighstrengthfordesignedloads
•Ithasuniformclosepackedanddensestructurewith
verylowabsorptionvalue
•Itismadeupofveyhardandresistantmineral
constituents
•Itisresistanttochemicallyreactivegasessuchas
sulphurdioxide,carbondioxideetc.

69. Deterioration and Preservation of
Stones
•Stones,likeallothermaterialsusedin
construction,deterioratewithtime.Some
undesirablechangesarelikelytodevelopin
themafteryearsofexposuretonatural
agencieslikewind,water,andtemperature.
Appearancegetsdefinitelyaffected.
Strengthqualitiesmaynotbeeasilyaffected
withtime,butwhentheydo,thedurability
andsafetyofthebuildinggetendangered.

70. Deterioration and Preservation of
Stones

71. Deterioration and Preservation of
Stones
CausesofDeterioration
•Theremaybeeitherphysicalorchemicalor
bothinnature.
PhysicalCauses
•Amongthese,thefrostaction,temperature
effectandtherubbingactionofwindsmay
bequitesignificant.

72. Deterioration and Preservation of
Stones

73. Deterioration and Preservation of
Stones
(i)FrostAction
•InColdHumidClimates,porousstonesmay
absorbmoisturefromatmospherequiteeasily.
Whenthishappensinwinters,waterwithinthe
poresfreezesandexpandsexertingtensile
stressesfromwithin.Thisnatureslowandsteady
process,calledfrostactionisrepeatedwinterafter
winter.FrostactioniscapableofSplittingand
SpallingonthesurfaceofStone.

74. Frost Action

75. Deterioration and Preservation of
Stones
(ii)TemperatureChanges
•Stoneslikeallothermaterialsexpandonheatingand
contractoncooling.TheirCoefficientofexpansion,isof
coursenegligiblewhenconsideringonshorttermbasis.But
whenconsideredformanyscoresofyearsandespecially
whenstonearemadeofdifferentmineralshaving
differentexpansionandcontractioncoefficientssome
minorstressesdodevelopwithinthestoneexposedto
heatingactionofthesun.
•TheSurfaceofstonesstartgettingaffected,apparently
insignificantlyinthebeginning.Theeffectdeservesdue
considerationwhenstoneareusedinaridregiononthe
exteriorportion

76. Deterioration and Preservation of
Stones

77. Deterioration and Preservation of
Stones
WindAction
•Strongwindsrichinsandanddustparticlesactas
virtualsandpapers.Thesearecapableofpolishingof
stoneswhentheyhaveauniformtextureandcomposition.
Butwhenthestonesaremadeupofminerals
constituentsofdifferenthardness,thesoftminerals
constituentsofdifferenthardness,thesoftmineralsget
polishedmoreandmoreandmaybegraduallyremoved
bypitting.Theadjoiningmineralmayalsofallaparton
losingthegrip.Henceaprocessofslowphysical
disintegrationstartsonthesurfaceofthestoneexposedto
windaction.
•Windactionisapowerfulscabbingprocessinareasof
strongwindslyingonthebordersofdeserts.

78. Wind Action

79. Deterioration and Preservation of
Stones
ChemicalCauses
•Theatmosphericmoistureandsomeoftheatmosphericgases
andvaporsemanatingfromtheindustriesarequiteharmfulfor
manytypesofstonesexposedtotheirdirectattack.
•(i)WaterVapors
•Wateronchemicalcombinationwithatmosphericcarbon
dioxidemakescarbonicacid.Thisacidhasmildcorrosiveaction
onsomestones.Thusitcanslowlyattackandeatupthestrongestof
rocks
•(ii)Limestoneandmarbles
•Arebothcomposedofcalciumcarbonate(CaCO
3).In
IndustrialtownswhereSO
3vaporsareemanatedfrommany
industrialchimneys,theymixwithatmosphericmoistureand
makeaninjurioussulphuricacid.Theacidreactswithcarbonate
ofthestoneconvertingthatintoasulphateandintheprocess
tarnishingthesurfaceofthestone.

80. Deterioration and Preservation of
Stones

81. Deterioration and Preservation of
Stones
•Thesohotdebatedcontroversyofthreat
deteriorationtothemarblesusedinTaj
MahalfromthesulphateemanationMathura
Refineryarebasedonthethisbasicfact.

82. Preservation of Stones
•Itisquitepossibletoprotectthestonefromquick
deteriorationbyadoptingoneormoreofthe
followingmethods:
CarefulSelection
•Whileselectingstonesinagivenarea,ageneral
assessmentabouttheweatheringresistanceofthe
stonecanbeformedfromquarries,oldexposureor
fromthestonesusedinthebuildings.Ifastonehas
showntoomuchdeteriorationatthoseplaces,itis
likelytodeteriorateinasimilarmannerwhenusedina
buildingconstructioninanewbuilding.Henceitmay
notbeselectedforuseinsimilarsituationexposedto
weather.

83. Careful Selection

84. Preservation of Stones
•Similarly,ifastoneistobeusedinanalready
establishedorproposedindustrialtown,its
compositionmustbegivendueconsideration.
Limestone,marblesanddolomites,allcarbonated
rocks,arelikelytodeterioratefast,especiallyon
exposedparts.Weshouldpreferuseofsiliceous
stoneslikesandstoneandquartziteinstead.
•Iftheareahasstrongwindsandlocatedcloseto
deserts,weshouldselectonlyfinetexturedstones
havinguniformcompositionandgoodhardness.
E.g.quartzitesinsteadofgranites.

85. Preservation of Stones

86. Preservation of Stones
(ii)CarefulConstruction
•Whileconstructingastonehouse,inpartorcomplete,asetof
precautionscanincreasethelifeandbeautyofthebuildingtoa
considerableextent.
•Suchas:
•Stonesofpropersizeandshapeshouldonlybeusedwithamortarof
matchingqualitysothatnoopenspacesareleftformoistureandgasesto
seeporgetin.
•Noledgeofstoneshouldbeleftprojectingoutasitmayactasa
gatheringplaceforwaterduringrains.
•Useofdifferentstonesinalternatelayeroreveninthesamelayer
shouldbeavoided.Homogeneityinthestoneconstructionisconsidereda
betterpolicy.
•Onlywellseasonedstonesbeusedinconstruction,whenstratified,
theirbeddedplanesshouldbegivenproperconsiderationwhileplacing
theminloadbearingposition.

87. Preservation of Stones

88. Preservation of Stones
(iii)Applicationofpreservatives.
•Whenastonehasalreadybeenusedandthereisariskofits
deteriorationbecauseofenvironmentalconditions,apreventivemeasure
maybetakenbyapplyingsomewellknownpreservativeonit.
•Apreservativeisaoilorapaintorasolutionwhichwhenappliedona
stoneprotectsitfromthedirectattackofsomedeterioratingagency.
Areallyeffectivepreservativemustbe
•Easilyapplicable
•Easilypenetrating
•Unleachable
•Economical
•Furtherthepreservativemustnotchangethenaturalappearanceof
thestoneandproduceoddsmell

89. Preservation of Stones

90. Preservation of Stones
•Alargenumberofpreservativeareavailableforpreventing
thedeteriorationofstones.Thefollowingarementioned
below
Linseedoil
•Itisusedbothincoldandboiledform.Boiledlinseedoil
willchangetheappearanceofstonetoadarkershade.
Paraffin
•Itiscommonlyusedinthedissolvedforminnaphtha.It
alsointerfereswiththeoriginalcolorofthestone.
CoalTar
•Itischeapandeffectivepreservativeexceptitchanges
thelookofthestone.

91. Preservation of Stones

92. Preservation of Stones
BarytaSolution
•Itissimplyasolutionofbariumhydroxideandhas
beenfoundresistantagainstsulphateattackson
stonesurface.Itreactswithcalciumsulphateforming
bariumsulphate,whichismorestableandprotectsthe
surfaceofthestonefromfurtherdeterioration.
Paints
•Whenstonedeteriorationhasspoiledthe
appearanceofastonetoaconsiderableextent,best
coursewouldbetocoveritwithapaint.Itwillstop
furtherdeteriorationandalsoimprovethelook.

93. Artificial Stones
Definition
•Itisastonelikemassmadebymixingtogethercrushed
stonepieceswithcementandwaterinpresenceof
coloringpigments.
Types
•Artificialstoneinthebroadestsinceoftheterm,maybe
bestcalledatypeofcementconcrete,thiscanbemade
invariousshapesandindifferentcomposition.The
componentofartificialstonesaredecidedbytheengineer
andpre-mixedproportionswithcementandwater.After
throughmixing,thepasteisfilledinpropermouldsand
allowedtosetin.Thereaftertheyareremovedand
placedonplainprotectedsurfaceforcuringand
hardening.

94. Artificial Stones

95. Artificial Stones
•Grooves,cavitiesandhollowcanbeprovided
inthestoneasdesiredatthemoldingstage.
•TerrazzoandMosaicarethesimpleand
commonvarietyofartificialstones.Interrazzo,
itismarbleintheformofchipsthatisthemain
materialusedwiththecementmixformakingthe
stone.
•IntheCaseoftiles,itisthetopsurfaceofthe
normalcementconcreteinwhichmarblechips
arespreaduniformlyduringthecasting
process.

96. Terrazzo and Mosaic

97. Artificial Stones
Uses
•Artificialstoneshavethegeneralproperties
andappearanceofnaturalstonestosome
extent.Thesehavetheadvantagethatthese
canbecastedandcuredattheplaceoftheir
useandintheanydesiredshape.Moreover,
thesestonesoftencanbegivenanydesired
polish.Forthesereasonsartificialstonesare
usedinbuildingstogivedecorativelooks.

98. Artificial Stones

99. References
•BuildingConstruction:DrB.C.Punmia
•CivilEngineeringMaterial:Prof.Singh
•InternetWebSites

100. Thanks…