Brick Arches

 Brick arches are ornamental ways of bridging openings which are comprised of small units bonded together around a curve or series of curves. Arches need no additional reinforcements as brick lintels do because of wedge shaped units as load increases, the unit in the arch becomes tighter.
                      Arches offer architectural view and enhance aesthetic beauty of buildings. They are used to cover openings of door and windows andtransfer the above loads to the side of walls. Various arches have been developed over centuries. This article gives details of arch designs, arch form work and precautions during construction of arches.


Brick Arches 

Brick arches are mainly classified into three groups according to their construction and structure.

Rough Brick ArchIn

rough arches the joints are usually wedge shaped. These arches are constructed where high standard finish is not required. Such arches are constructed where plaster works are done. Bricks are not chamfered in construction of this arch.

Fine Axed Brick Arch

Fine axed arches are constructed carefully by setting bricks into required shape. The bricks are cut into wedge shape properly and are constructed where fine work is required. These arches may be constructed with bricks in contrasting colors. The finished shape of this arch gives pleasing appearance.

Gauged Brick Arch

Gauged arch is very ornamental and expensive. The bricks should have fine dressing before use. Also the joints between bricks should be very fine. These arches should be constructed by skilled mason who has sound knowledge of geometry.

Arch Designs
Flat Arch

A flat arch is suitable only for small spans and light load. It is constructed mainly on doors and windows in ordinary buildings. The square shape of this arch is decorative and non load bearing. Generally it is used to cover reinforced lintel which bears the load of wall from above.

Circular Arch

Circular arch is suitable for long spans and can take heavy load. In past these arches were constructed over bridges but nowadays they are constructed in buildings where architectural appearance is required. They add to the beauty of buildings.

Semi-circular arch

Semi-circular arch is very simple to construct or design as there is no complex geometry or cutting of bricks. Its semicircular shape with all the bricks facing towards the centre of the arch creates a wonderful view. Two or three rows of bricks are layered to add decorative touch to the beauty of the building.

Arch Centering/Form Work

Arch centering is used for same purpose as a turning piece i.e. the temporary spot to carry arch load during construction over an opening. It is made up of a number of small sections and timber members into required shape. Arch form work can conveniently be used over large spans.

Precautions for Brick Arches

• The length and width of the arches should be according to drawings. 
• The quality of bricks should be good having required strength and should not show any efflorescence (salt on face). 
• There are minimum brick bats brick arches. 
• The sand used for brick mortar should be of required FM (Coarser) with no silt. It should not have fine grains and be free from silt etc.
• The mixing of mortar should be proper with required quantity of water. It should not be dry or liquid. 
• The bricks are soaked in water before use otherwise these will absorb water from mortar and the bonds will be weak. 
• The water should penetrate to the core of bricks but the bricks should be skin dry i.e. from outside when it’s used in actual. 
• The bricks are absolutely aligned horizontally and in a straight line which can be checked by a stretched string across the face. Also they are vertically aligned which can be checked with a plumb bob. 
• The courses or layers of bricks are level. This can be checked with a spirit level.
• The thickness of joints is not more than 1 cm and the joints should be filled with mortar fully without any gaps. 
• The joints are pushed inside when cement mortar is still wet so that later plastering can be done effectively. 
• Brick work should be kept wet for seven days so that the mortar may gain its full strength. 
• There are no continuous vertical joints and the bricks, sand and cement used in brick work should be according to their specifications .

ARTICLE SOURCE : GHAREXPERT