Presented By:Presented By:Engineer LATIF HYDER WADHOEngineer LATIF HYDER WADHOMehran University of Engg: & Technology KhairpurMehran University of Engg: & Technology KhairpurCivil Engineering MaterialsCivil Engineering Materials11ststTerm 1Term 1ststYear B.E.CivilYear B.E.Civil
Tiles:A tile is a special type of brick which is often largerthan an ordinary brick.Tiles are mostly used for roofing and paving purposes.Standard size of tiles:Tiles are manufactured in different sizes in Pakistan.The most popular sizes are:(1)12’’ x 6’’ x 1 1’’4(2) 12’’ x 6’’ x 2’’(3) 9’’ x 4 1’’ x 2’’2
Tiles are classified into groups on the basisof construction material.(1) Material basis(i) Common tiles(ii) Encaustic tiles
Depending upon their Use(1) Roofing Tiles(a) Plain Tiles(b) Pot Tiles(c) Allahabad Tiles(d) Mangalore Tiles(e) Concrete Roofing Tiles(2) Flooring/Paving Tiles(3) Drain Tiles
(1) CLASSIFICATIONOFTILESBASED UPONMATERIAL USED
(i) Common tiles:Common tiles may be used for roofing.Flooring and walling also. Common tiles arepan tiles, pot tiles and flat tiles.(ii) Encaustic Tiles:These tiles are prepared by mixing colorswith the clay before burning. These are usedfor decorative purposes.
(i) Roofing tiles:These may be flat like slates ormay be made to different shapes.Some of the common varieties arediscussed below.
(a) Plain tiles:The size of these tiles is 25 cm x 15cm to 28 cm x 18 cm and thicknessvaries from 10 mm to 17 mm.(b) Pan tiles:These tiles are curved in section.These are 33 cm to 38 cm long and23 cm to 28 cm wide
(c) Pot tiles:These are semi circular insection and taper along thelength. The diameter at largerend is about 23 cm and at thesmaller end it is about 20 cm.
(d) Allahabad tiles:These consist of two sets of tiles. The lowerones are flat tiles with upturned sides. Endwidths reduce from 27 cm to 23 cm and thelength is about 38 cm. The over tile is halfround in section and tapers from 16.5 cm to 12cm in diameter. Half round tiles are mouldedon a potters’ wheel as a round taperingcylindrical tile. Two longitudinal cuts are givento the cylinder while still not dry. With this it iseasy to break it into two semicircular tiles afterburning.
(e) Mangalore tiles:These are flat pattern tileswith suitable key projection.About 16 tiles are required tocover one square meter ofroof.
(f) Concrete roofing tiles:Tiles of any shape, size or colourcould be made with cementconcrete. These are more strong,durable and weather resistant.
(2) Flooring or Paving tiles:These are usually thicker than roofing tiles andvary from 15 mm to 30 mm in thickness. Theirshapes are square, hexagonal or any of othergeometrical pattern and may be coloured, ifdesired.Depending upon properties of clay flooring tilesare classified as: class 1, class 2, class 3 tiles.Maximum water absorption percentages in caseof these tiles are 10, 19 and 24 respectively.
(3) Drain tiles:These are curved tiles made invarious shapes and sizes to suit thework in which they are to be used.Tiles to be used in the constructionof sewage carrying drains shouldbe glazed.
MANUFACTURING OF TILES:Six main operations are involved inthe manufacturing of tiles:1.Selection of suitable clay2.Preparation of clay3.Moulding4.Drying and Shaping5.Burning6.Cooling
(1) Selection of suitable clay:For manufacturing of tiles,we require superior type ofclay. The clay should becompletely free from grit,pebbles and other organicmatter.
(2) Preparation of clay:This is done by mixing water withclay in a tank and storing it in dampcondition. The solution is thenallowed to stand quietly in the tankresulting in the setting and leavingof coarse particles. Water containingfine clay in solution is rained off toother tanks where it is allowed todry leaving fine clay ready formoulding.
(3) Moulding:Moulding operation is done on the groundspecially prepared for that purpose. All theinstruments which are used in the mouldingshould be present.The moulder sprinkles ashes over the clayand start to mould according to the requiredsize of tiles on the smooth and leveledsurface, when the number of 10 to 15 tilesare prepared they are taken for drying andshaping.
(4) Drying and Shaping:Two days after moulding, the tilesare given proper shape and thenthey are placed on their edges anddried for about two days. Onething should be kept in mind thatwe take care to crack and wrapand they should be dried slowly.
(5) Burning:Tiles are burnt in a kiln which is incircular shape. Tiles are kept on theiredges and door ways are closed withbricks. The maximum temperature of tilesshould be 2200degreeF for about threehours. This process is repeated for secondtime.The kiln is isolated after it has cooleddown. The kiln should be protectedagainst bad weather specially on the windside by temporary roofing.
(6) Cooling:After burning, cooling is done for 3 to5 days.(OR)3 to 5 days are required for cooling oftiles.