Mortar (masonry)

Masonry is an assemblage of masonry unit like bricks, blocks of stones, which are bonded together with mortar. Masonry can be a load bearing, non load bearing, architectural or a retaining structure.

 Important term used in Masonry

Stone:-

• Granite

• Limestone

• Laterite 

• slate 

• Sandstone

Block :-

Brick:-

It is an artificial masonry unit manufacturer using appropriate earth mix with water in a fixed proportion moulded into suitable size and fired in a kiln to attain strength.

Mortar :-

It is a binding material comprising of cement materials and sand.Mortar are generally identified by the ratio of the volume of cementing material to the volume of sand.The type of mortar commonly used lime mortar, cement mortar and cement line mortar.

Joint:- 

The gap between masonry units comprising of mortar to bind them together and to maintain horizontal and vertical alignment is called as a joint.
There are various type of joint-

• Bed joint
• Cross joint
• Collar joint
• Course

 Ranking :-

 Ranking is the process of removing mortar from the joints of masonry using a trowel or a suitable tool.

Pointing:-

It is the process of finishing the mortar joint of masonry.The joint are raked to a suitable depth using a tool with a straight edge.The raked out area can act as a key for the next layer of surface finishing or for aesthetic.

 Bond stone :

These are horizontally laid stones that run across the width of the wall tying it together.

 Key:-

 A key in masonry is the interlocking stone left as a connector between course in the vertical and horizontal direction at suitable interval for further masonry work to continue.

Sill :-

It is the structural member forming the lower side of an opening onto which a door or window can be fixed.

Lintel:-  

It is a horizontal structural member that  support  the load over an opening such as a door window. lintels can be pre-cast, cast in situ, with adequate bearing on either side as per the design. Generally bearing should be equal to the depth of the lintel but not less than 100 mm.

Aluminium templates:- 

These are aluminium frame that are used during block work to leave precise opening for door, window and ventilator.

Mason:-

 A construction tradesman who is specializes in masonry.

Stone masonry :- 

 The stone that are removed from a quarry do not have a specific shape or size. Hence  to make them suitable for construction the stone will have to be cut to the desired shape and size.This can be done manually using a hammer and chisel or by using power saw and grinding machine suitable for the job.The process is called shaping of stones.
Upon a special requirement the stone dressed.The process of cutting the stone to a final shape and giving a suitable surface finish to cater to a specialized requirement is called as strong dressing.

Categories

Stone masonry can be of two categories

1. Rubble masonry
2. Ashlar masonry

Rubble masonry :-   

Ashlar Masonry:- 

Mortar is a  plastic mixture of binding materials, fine aggregate, water and stone masonry for other structural units.

Function of mortar

• To Bond brick or Stones in the construction of break or stone masonry
• To distribute the load uniformly on the lower layer
• To form a uniform bad between different courses of masonry
• To cover exposed surface of walls and joints with plaster or pointing to provide a smooth hard and decorative wall surface
• To fill empty joints by grouting.

Properties of ideal mortar

• It develop good adhesion with brick or stones

• It provide sufficient resistance to water penetration.

• It withstands the stress developed.

• It possesses quick setting property for increasing the speed in construction.

• It is easily workable and is also durable

• It does not affect the material being joined.

• It is economical.

 Classification

The binding property of binding agent and aggregate are classified as below :-

1. Cement mortar
2.  Lime motor
3. Special motor

Required strength of mortar in masonry

 Cement mortar

1.  Damp proof course 1:2
2.  General brickwork 1:6
3.   Stone masonry 1:6
4.   For arch work 1:3
5.   pointing work 1:1 to 1:3
6.   Brickwork below ground level 1:3 to 1:4

  cement plaster

1.   External Plaster 1:5 to 1:6
2.   Internal  Plaster 1:5 to 1:6
3.   R.C Plaster for ceiling 1:3 to 1:4