Building Materials and Construction2. STONE MASONRYGeneralMasonry is defined as the art of construction in which building units, such as clay bricks, sand-lime, bricks, stones, Pre-cast hallow concrete blocks, concrete slabs, glass bricks, combination ofsomeofthesebuildingunitsetcarearrangedsystematicallyandbondedtogethertoformahomogeneous mass in such a manner that they can with stand point to other loads and transmitthen through the mass without fail or disintegration.Masonry can be classified into the following categories.1. Stone masonry2. Brick masonry. !allow block concrete masonry". #einforced masonry$. %omposite masonryTechnical terms1. Course: & course is a hori'ontal layer of bricks or stones. (ts thickness is generally e)ual tothe thickness of a stone or brick plus thickness of one mortar *oint.2. Bed: +he surface of a stone perpendicular to the line of pressure ,lower surface of bricks orstones in each course-.. Back:+he inner surface of wall not e.posed is called back. +he material forming back isknown as backing". ace: +he e.terior of the wall e.posed to weather is known as face. +he material used in thefacing of wall is known as facing.$. !eartin": (t is the interior portion of a wall between facing and backing./. !eader: & header is a full stone unit or brick which is so laid that its length is perpendicularto the face of the wall. +hus, the longest length of header lies at right angles to the face of thework. (n the case of stone masonry header is sometimes known as through stone. 0. Stretcher: & stretcher is a full stone unit or brick which is so laid that its length is along orparallel to the face of the wall. +hus, the longest length of the stretcher lies parallel to theface of the work. 1. Bond: +he method of arranging bricks or stones so that the indi2idual units are tied together.+he bond distributes the load coming on the structure e2enly and pre2ents the formation of a2ertical crack.3. #oint: +he *unction of ad*acent units of bricks or stones is known as a *oint. 4oints parallel tothe bed of bricks or stones are known as bed *oint. Bed *oints are thus hori'ontal mortar *ointsupon which masonry courses are laid. 4oints perpendicular to the face of the wall is known ascross-*ointor2ertical*oints. &ll*ointsareformedincementmortar,limemortarormudmortar. & *oint which is parallel to the face of the wall is known as wall *oint.Compiled by Dr. Prashanth J. and Dr. Harish N. Page 1Building Materials and Construction15. Cornice: & cornice is a course of stone pro2ided at the top of wall. (t is generally mouldedand gi2en ornamental treatment. (t is weathered and throated to dispose of rainwater. (n orderto pre2ent from o2erturning of the cornice, sufficient bearing and e.tra weight at the top inthe form of parapet wall should be pro2ided.11. Closer: & piece of stone which is used to close up the bond at the end of stone courses isknown as a closer and it helps in pre2enting the *oints of successi2e courses to come in a2ertical line.12. S$alls: +he chips of stones used for filling the empty spaces in stone masonry.1. %uoins:+he e.ternal corners or angles of a wall surface are called )uoins and the stonesforming )uoinsareknown as)uoin stones. +he)uoin stonesareselectedfromlargeandsound stones and their beds are properly dressed.1". Sill: (t is a hori'ontal stone, concrete or wood, employed for the purpose of shedding off rainwater from the face of wall immediately below the window opening.1$. Throatin":& groo2e cut pro2ided on the underside of a pro*ecting course of masonry inorder to check the creepage of rainwater from the underside of the pro*ected portion.1/. &eatherin":+heupper surface ofstoneusedfor sill,cornice andcoping isdressedinaloping way so that the water may flow off easily. +his is termed as the weathering. 10. Cor'el: (t is the e.tension of one or more course of stone or brick from the face of a wall toser2e as a support for roof truss, beam, weather shed etc. +he corbel should e.tend at leasttwo-third of their length into the wall.11. Co$in":(t isthecourseplaceduponthee.posedtopofane.ternal wall topre2ent theseepage of rainwater. +his course is generally pro2ided at the top of a compound wall or aparapet wall and it is suitably weathered and throated. 13. Strin" course:(t is a hori'ontal course pro2ided at suitable le2els between the plinth andcornice. (t breaks the monotony of a plane surface and it is sometimes moulded and gi2enarchitectural treatment. +he string course is suitably weathered and throated so as to thormoff the rainwater clear of the wall surface. 25. #am's: +he sides of the openings such as doors, windows etc. are known as the *ambs andthey are constructed similar to )uoins. +he *ambs may be either plain or s)uare or splayed orrebated. +he splayed *ambs are proffered as they allow the shutters to open up at an obtuseangle and thus permit more light and air into the room.21. Buttress: (t is a sloping or stepped masonry pro*ection from a tall wall intended to strengthenthe wall against the thrust of a roof as shown in figure below.22. Throu"h stone: & through stone is a stone header. +hrough stones are placed across wall atregular inter2al. (f the thickness of wall is small, through stone may be of length e)ual to thefull width of the wall. (f, howe2er the wall is considerable thick, two through stones with ano2erlap are pro2ided as shown in figure. +hrough stones should be strong, and non-porous,and should be of sufficient thickness.Compiled by Dr. Prashanth J. and Dr. Harish N. Page 2Building Materials and ConstructionCornice Co$in"(arious terms Strin" courseCompiled by Dr. Prashanth J. and Dr. Harish N. Page 3Building Materials and Construction)i**erent t+$es o* ,am's Buttress Throu"h StoneStone masonr++he construction of stones bonded together with mortar is termed as stone masonry where thestones are a2ailable in a abundance in nature, on cutting and dressing to the proper shape, theypro2ideaneconomical material fortheconstructionof2ariousbuildingcomponentssuchaswalls, columns, footings, arches, lintels, beams etc.-ses o* stone masonr+Stone masonry construction is used in,i- Building foundations, dams, monumental structures,ii- Building walls, piers, columns, pillars, light houses and architectural works.,iii- &rches, domes, lintels and beams,i2- #oofs, pa2ing *obs ,2- %ladding works,2i- #ailway ballast, black boards and electrical switch boardsCompiled by Dr. Prashanth J. and Dr. Harish N. Page Building Materials and ConstructionSelection o* stone *or stone masonr++he selection of stones for stone masonry depends upona. &2ailabilityb. 6ase of workingc. &ppearanced. Strength and stabilitye. Polishing characteristicsf. 6conomyg. 7urability+he table gi2en below broadly outlines the different types of stones used for different purposes.Sl. No..ur$oseStones used 1.!ea2y engineering works 6.8 stocks, breakwaters, light houses, bridges, piers 9ranite, gneiss 2.Buildings situated in industrial towns9ranite and compact sandstone .Pa2ements, railway ballast, door sits and steps9ranite slabs and slate".6lectrical switch boardMarble slabs and slate $.:ire resistance works%ompact sandstone /.%ar2ing and ornamental worksMarble and laterite 0.:ace work and architectural purposesMarble, granite closer grained sand stone #oints in stone masonr++he 2arious *oints commonly used in stone work are described below81. Butt or s)uare *oint8 +his *oint is formed by placing two stones side by side.2. #ebated or lapped *oint8 +his *oint is usually pro2ided by stones laid on slopes to pre2entthe mo2ement of one stone o2er the other by sliding.. Bed or tabled *oint8 (ts function is similar to that of rebated or lapped *oint.". %ramped *oint8 +he function of cramp which may be made of slate or any metal, is topre2ent the tendency of the *oint to be pulled apart.$. Plug *oint8 Plug *oint is an alternati2e of cramp *oint and consists of plug holes, madedo2etail-shaped in plan and cut below the top surface of stones. +he stones are *oined byfilling the holes with cement or lead./. 7owel *oint8 +his type of *oint ensures stability of the components against displacementor sliding. +he dowels may be of slate, gun metal, copper or brass. +hey are generally setin cement mortar.0. 4oggle or groo2ed or tongued *oint8 +o pre2ent sliding along the side *oints, *oggle madeup of metal or slate is placed in between the groo2e between the two ad*acent stones.1. #usticated*oint8 +histypeof*oint isfre)uentlyusedinplinthsormasonryinlowerstoreys of buildings to gi2e the structure massi2e appearance.Compiled by Dr. Prashanth J. and Dr. Harish N. Page !Building Materials and ConstructionButt #oint /a$$ed #oint

Ta'led #oint Cram$ed #oint

.lu" #oint )o0elled #oint

Rusticated #oint#o""le #ointT+$es o* stone masonr+Compiled by Dr. Prashanth J. and Dr. Harish N. Page "Building Materials and ConstructionBased on the arrangement of the stone in the construction and degree of refinement in the surfacefinish, the stone masonry can be classified broadly in the following two categories81. #ubblemasonry8 ;ndressedorroughlydressedstonesareusedinthistypeofmasonrywork. +he *oints are considerably wide.2. &shlar masonry8 %arefully dressed stones of uniform si'e are used and the *oints betweenstone blocks are 2ery thin and uniform.12 Ru''le masonr+:(n this category, the stones used are either undressed or roughly dressedha2ing wider *oints. +he masonry has wide *oints, since stones of irregular si'es are used.#ubble masonry may be of following types,i- ;ncoursed random rubble masonry.ii- %oursed random rubble masonry.iii- ;ncoursed s)uare rubble masonry.i2- %oursed s)uare rubble masonry.2- Built to regular courses masonry.2i- Polygonal rubble masonry.2ii- :lint rubble masonry.2iii- 7ry rubble masonry.(i) Uncoursed random rubble masonry: +his is the cheapest, roughest and poorest form of stonemasonry. +he stones used in this type of masonry 2ery much 2ary in their shape and si'e and aredirectly obtained from )uarry. Since, the stones are not of uniform si'es and shapes, greater careandingenuityha2etobee.ercisedinarrangingtheminsuchawaythat theyade)uatelydistribute the pressure o2er the ma.imum area and at the same time long continuous 2ertical*oints are a2oided.Sound bond should be a2ailable both trans2ersely as well as longitudinally. +rans2erse bond isobtained by the liberal use of headers.