Brick_bonds civil engineering introduction

It is an slide for bricks bonds.

1. Bonds in Brickwork Bonds is the method of arranging the bricks in courses and vertical joints of successive courses are not in same line. Rules for bonding Bricks should be of uniform size Amount of lap should be minimum ¼ brick along the length of the wall and ½ brick along thickness of wall. Use of brick bats should be discouraged except in special locations Vertical joints in alternate courses should be along same perpend .

2. TYPES OF BONDS Stretcher bond Header bond English bond Flemish bond Zig Zag bond

3. Stretcher bond Bricks are laid as stretchers on the faces of wall, length of bricks is along the face Use for walls which have thickness of half brick i.e. 9 cm Used as Partition walls, chimney stacks This bond is not possible if thickness is more

4. Header bond Bricks are laid down as headers, width is along the direction of wall. Used only when thickness of wall is equal to one brick This bond is not suitable for transmitting pressure in the direction of wall, hence not used for load bearing walls. Used for curved brick work

5. Most commonly used bond for all wall thickness Strongest bond; Alternate course of headers and stretchers; Vertical joints of header courses come over each other; same with stretcher. In order to break the vertical joints in the successive courses, it is essential to place queen closer after the first quoin header in each heading course. In a stretcher course, the lap must be minimum ¼ of their length. English bond

6. Flemish Bond Each course is comprised of alternate headers and stretchers. Every alternate course starts with a header at the corner (quoin header). Queen closer are placed next to quoin header in alternate course to develop the face lap. Two types: Double flemish bond; Single flemish bond In double; each course presents the same appearance both in front and back face; presents better appearance than English bond In walls having thickness equal to odd multiple of half bricks, half bats and three quarter bats are used. In single flemish ; uses English bond backing and double flemish bond facing Can be used for walls having thickness at least equal to 1 ½ brick

7. Comparison of English and Flemish bond English bond is stronger than Flemish bond for walls thicker than 1 ½ brick Flemish bond gives more pleasing appearance and requires greater skill than English bond Broken bricks in the form of bats can be used in Flemish bond

8. Used for making ornamental panels in the brick flooring

9. Comparison of Brick and Stone masonry Brick masonry can be constructed with less skilled masons in comparison to stone work. Hence brickwork is cheaper. No special lifting arrangement is required for bricks Brick masonry can be used in any type of mortar; mud mortar can be used in low rise houses Better fire resistant than stones

10. Stone masonry is stronger than brick masonry of same wall thickness Life of stone masonry longer than bricks Stone masonry doesn’t require external plaster. Stone masonry more water tight than bricks.

11. Defects in Brick masonry Sulphate attack : sulphate salts present in brick react with hydraulic lime in case of lime mortar and with alumina present in cement mortar, volume of mortar increases; chipping and spalling of bricks Crystallization of salts : If bricks containing soluble salts get dissolved with water, appear in the form of fine white crystals on the surface; Efflorescence Corrosion of iron or steel fixture Drying shrinkage leading to cracks