Masonry Construction Prepared By Alka Shah Civil Engineering

Masonry Construction Prepared By: Alka Shah Civil Engineering

Sub Topics: Ø Stone masonry constructions Ø Brick masonry constructions Ø Cement based block masonry construction

Stone Masonry Constructions

Sub Topics: Ø Technical terms Ø Types Ø Joints

Sub Topics: Ø Technical terms v Corbel-A short stone cantilever jutting from the face of a wall to form a bearing.

Sub Topics: Ø Technical terms v Bond – arrangement of layers of stones v Through stone - The stone extending through the entire thickness of a wall to increase its lateral stability is called a through or bond stone.

Earthquake tips IITK

Sub Topics: Ø Types (according to SP 20 1991) 1. Random Rubble Un Coursed Masonry 2. Random Rubble Coursed Masonry 3. Ashlar Masonry

Ø Types (according to SP 20 1991) 1. Random Rubble Un Coursed Masonry

Ø Types (according to SP 20 1991) 2. Random Rubble Coursed Masonry

Ø Types (according to SP 20 1991) 3. Ashlar Masonry

Joints in Stone Masonry 18

Introduction • In masonry, joints are the spaces between stones, that are filled with mortar, grout or metal or timber components • joints can be made in a series • In stone masonry the joints are not of uniform thickness, shape, size 19

Types of joints 1. Butt joint 2. Reabated joint or Lapped joint 3. Table joint or Bed joint 4. Cramped joint 5. Plug joint 6. Dowel joint 7. Rusticated joint 8. Joggle joint 20

1. Butt joint • In this type of joint, the dressed edges of two stones are placed side by side. 21

2. Reabated joint • This type of joint is provided in arches, gables, copings, etc. where the stones are laid on slopes to prevent the movement of one stone over the other by sliding. 22

3. Table joint • This type of joint is provided in sea wall, etc. to prevent the lateral movement of stones. • The joint is formed by making a joggle in the bed of stone. • The height of projection is kept 30 to 40 mm, and the width is kept equal to 1/3 rd the width of the stone. 23

Fig. table joint 24

4. Cramped joint • In this type of joints, the metal cramps are used to prevent the tendency of the joint to be pulled apart. • The dovetail shape holes are made in the both stones to be joined. • The cramps are usually made of non-corrosive metals, such as gunmetal, copper, etc. • After placing the cramp in position, the joint is grouted and covered with cement, lead or asphalt. 25

Fig. cramped joint fig. metal cramp 26

5. Plug joint • The plug joint is an alternatively of cramp joint. • It consists of plug holes of dovetail shape in plan and cut below the top surface of stones. • The stones are joined by filling the holes with cement or lead. 27

Fig. plug joint 28

6. Dowel joint • This type of joint is used to ensure the stability of the adjacent stones against displacement or sliding. • The joint is formed by cutting the rectangular holes in both the stones and interesting the dowels made of slate, gun metal, copper or brass. • The dowels are set in cement mortar. 29

fig. dowel joint 30

7. Rusticated joint • This type of joints are generally used in plinths or masonary in lower storeys of buildings to give the structure splendid appearance. 31

8. Joggle joint • The joggle-joint is made of metal or slate, which is placed between the groove provided in two adjacent stones; to prevent sliding along the side joints. 32

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IS provisions for stone masonry constructions Ø Hand book on Masonry design and construction (IS SP 20: 1991) Ø Improving earthquake resistance of Low strength masonry buildings — Guidelines [IS 13828 : 1993 (Reaffirmed 2008) ]

Brick Masonry Constructions

Types of Bricks • Traditional bricks: no standard size, may vary from place to place. . • Length: 20 to 25 cm, width 10 to 13 cm, thickness 5 to 7. 5 cm • Commonly adopted size: 23 cm x 11. 4 cm x 7. 6 cm. • Modular bricks: • According to IS nominal size: 20 cm x 10 cm which includes mortar thickness. . Actual size of brick: 19 cm x 9 cm (According to IS)

Classes of Bricks • First class: Strictly conform to IS so that ten layers of brick laid in mortar will form masonry of 1 m height. • Plastic earth free from saline deposits. Good uniform colour, well burnt, good ringing sound when struck, straight and sharp edges with even surface. • Free from cracks, chips, flaws, nodules of lime. • When immersed in water for 1 hr don’t absorb water more 1/6 th of their weight. • On drying don’t show any efflorescence. . First Class

Classes of Bricks Second class: Conform to IS but slightly irregular in shape and colour. • Fully burnt, good ringing sound, when immersed in water for 1 hr don’t absorb water more 1/4 th of their weight Third class: Quite irregular in size, shape, and finish • Not burnt fully, reddish -yellow colour • Low crushing strength • Not used for quality brick masonry work Second Class Third Class

Sub Topics: Ø Types and materials of brick masonry constructions (Self Study) Ø Technical terms Ø Bonds in brick masonry Ø Construction of arches Ø Introduction to IS provisions for brick masonry constructions

Technical Terms • Stretcher: Longer face of the brick(19 cm x 9 cm) as seen in the elevation of the wall. üA course when all the bricks are laid as stretchers on facing is known as stretcher course. • Header: Shorter face of the brick(9 cm x 9 cm) as seen in the elevation of the wall. üA course when all the bricks are laid as headers on facing is known as header course. • Lap: Horizontal distance between the vertical joints of successive brick course. • Bed: The lower surface of the brick(19 cm x 9 cm) when laid flat. • Arris: An edge of the brick.

• Closer: Portion of brick with the cut made longitudinally and is used to close up bond at the end of course. ü Prevents the joints of successive course to come in vertical line. . • Queen-closer: Portion of brick obtained by cutting brick lengthwise in to two portion. . i. e. it is a brick which is half as wide as the full brick, known as queen-closerhalf. ü If queen closer is broken into two pieces it is known as queen-closer-quarter. . • King closer: Portion of brick which is so cut that the width of one of its end is half that of a full brick while width at the other end is equal to full width. ü Obtained by cutting the triangular piece between centre of one end and centre of other side. King Closer Queen Closer

• Bevelled closer: Special type of king closer in which whole length of the brick is bevelled in such a way that half width is maintained at one end and full width is maintained at the other end. • Bat: The portion of brick cut across the width. ie. Smaller in length than full brick. ü If the length of bat is equal to half the length of original brick known as half bat, having its length equal to three-quarters of length of full brick known as threequarter bat. Bat

• Frog or kick: An indentation in the face of a brick to form a key for holding the mortar. ü If frog is only on one face, brick is laid with face on the top. Sometimes it is provided on both the faces.

• Racking back: termination of a wall in a stepped fashion… • Toothing: Termination of a wall in such a fashion that each alternate course at the end projects, in order to provide adequate bond for future extension Racking back Toothing

Bonds in Brick Work Ø Method of arranging bricks in courses so that individual units are tied together and the vertical joints of the successive courses do not lie in same vertical line Ø Distribute the concentrated loads over a larger area Ø Types ü Stretcher bond ü Header bond ü English bond ü Flemish bond

Stretcher Bond • All the bricks are laid as stretchers on the faces of the walls. • The length of the brick along the direction of the wall. • Used only when thickness of wall is equal to half brick. • Used for partition wall, sleeper wall or chimney wall, division wall etc. • Not suitable if thickness of wall is more than one brick.

• • Header Bond All the bricks are laid as headers on the faces of the walls. The width of the brick along the direction of the wall. Used only when thickness of wall is equal to one brick. Overlap is achieved by using 3/4 th brickbat in each alternate course. Does not have strength to transmit pressure in the direction of length of the wall. Not suitable for load bearing wall. Useful for curved brick work where stretcher would be inconvenient, use in construction of footing.

English Bond • • • Most commonly used bond for all wall thickness. Strongest among all bonds. Alternate courses of headers and stretchers. Vertical joints of the header and stretcher course come over each other. It is essential to place queen closer after the first header (quoin header) to break the vertical joints in successive courses.

1 brick English bond 1½ brick English bond

Flemish Bond • Each course is comprise of header and stretchers. • Every alternate course starts with a header at the corner(quoin header). • Quoin closer are placed next to quoin header in alternate course to develop the face lap. • Every header is supported over the stretcher below it. • Types: Double Flemish bond Single Flemish bond

Ø Types of joints in Brick Masonry

Ø Types of joints

Comparison between Flemish and English bond • English bond is stronger than Flemish bond for wall thicker than 1½ brick. • Flemish bond gives more pleasing appearance than English bond. • Broken bricks can be used in the form of bats in Flemish bond however more mortar is required. • More skill is required in Flemish bond.

Construction of brick arch ü ü ü Centring Spanning Mark points of brick on centring Placing centring in position start putting brick first with keystone

IS provisions for Brick masonry constructions Ø Hand book on Masonry design and construction (IS SP 20: 1991) Ø Improving earthquake resistance of Low strength masonry buildings — Guidelines [IS 13828 : 1993 (Reaffirmed 2008) ] Ø Earthquake tips IITK Ø Earthquake resistant design and Construction of buildings — Code of practice [IS 4326 : 1993 (Reaffirmed 2003)] Ø Code of practice for Structural use of unreinforced Masonry [(IS 1905: 1987) (Reaffirmed 2002)]

Cement Based Block Masonry Constructions

Cement based block Masonry Constructions

Cement based block Masonry Constructions

IS provisions for Cement Based Block masonry constructions Ø Hand book on Masonry design and construction (IS SP 20: 1991) Ø Construction of hollow and solid Concrete block masonry - Code of practice (IS 2572: 2005)