Definition Brick Masonry
Brick is most generally used building material and used for constructing walls, floors, and so on. The word brick is referred to a rectangular product made of clay.
It is constructed by laying a brick in mortar in such an organized manner to build a solid structure that resists placed loads. There are several types of bricks and mortars, which are used in brickwork.
Types of Bonds Commonly used in Brick Masonry Work
Bonding is the technique of setting up bricks with mortar to tie them with each other. The vertical joints provided in the brick masonry should not continue in each layer. It is not possible to construct the wall without proper bonding in between bricks. Some of the bonds generally used to construct the wall are:
- English Bond
- Stretcher Bond
- Header Bond
- Flemish Bond
In this type of bond, alternate bricks are placed as header and stretcher in every course. A queen closer is placed after the header to produce a good overlap. The queen closer is not needed in the stretcher course.
This type of bond is generally used in practice. It is considered the strongest bond in brickwork.
In this style of bond, all the bricks are laid in the stretcher courses. So that Wall having stretchers in the facing.
In this bond, all the bricks are laid in the header courses. So that wall having headers in the facing.
Alternate bricks are placed as header and stretcher in every course. This bond is provided a better look than the English bond. However, it is not much strong as the English bond as it contains a lot of stretchers.
Types of Mortar used in Brick Masonry Work
Mortar is a workable paste used to bind bricks together and fill the gaps between them. Mortar can be a mixture of sand, a binder such as cement or lime, and water and is used as a paste which is then set hard as well as mud mix with water to make mud mortar.
Brick Work in Mud Mortar
In this type of masonry work mortar is made from pure Mud and mixed with water. Mud mortar is utilized to fill joints in between bricks. The maximum thickness of mortar in each layer is 12 mm in this type of masonry work. In this type of masonry work, the wall should be constructed maximum height of 4 Meters. This type of masonry is not very much strong. This type of masonry work is very economical.
Brick work in cement
In this type of brick masonry works by laying bricks in cement mortar. The thickness of Cement mortar is used for each layer in Masonry work is a Maximum of 12 mm. Cement Mortar is also used to fill joints between Bricks in Masonry work. Brick masonry with cement mortar is much stronger.
Classes of brick
These bricks are well burnt, have a uniform color, water absorption of less than 15%, and minimum compressive strength of 10.5 N/mm2. They have a plane, rectangular faces with equal sides, and right-angled edges.
Second class Brick:
Bricks are rough and the shape is slightly irregular surface with water absorption below 20 % and minimum compressive strength of 7 N/mm2.
Third class Brick:
They are not uniform in shape and are slightly under burnt should not have water absorption of more than 25%. Mostly used for temporary structures.
Over burnt bricks:
They are over-burnt, irregular in shape, tough, and strong. These bricks are used in foundation, road material, and flooring.
Tests for brick
Compressive strength test
The minimum number of samples needed for compressive strength is five. The sample brick is immersed in water for twenty-four hours. The frog of the brick is filled up flush with 1:3 mortars and brick is stored under wet jute bags for 24 hours followed by immersion in tidy water for three days.
The samples are placed between the plates of the compression testing machine. The load is applied axially at a uniform rate of 14 N/mm2 and the maximum load at which the sample fails is noted for the determination of compressive strength of brick given by:
Compressive strength = Maximum load at failure/ Loaded area of brick
Water absorption test
Dry the samples in a ventilated oven at a temperature level of 105 to 115 degrees till it attains substantially constant mass. Cool the samples to room temperature and the weight is (M1).
The sampling is totally dried as in preconditioning after that Immerse in clean water at a temperature level of 27 ± 2 degrees for 24 hours. After that take out the samples and clean out any traces of water with a wet cloth and evaluate the specimen. Complete the evaluation 3 minutes after the samples have been removed from the water and record the weight (M2).
Water absorption = (M1-M2)/ M1 X 100%
Firstly, the end of the bricks is put in the dish, the depth of immersion in water being 25mm. The entire arrangement is put in a warm well-ventilated room up to the time all the water in the dish is soaked up by the samples and the surplus water evaporates.
The dish including the brick is covered with an appropriate glass cylinder to avoid excessive vaporization from the dish that may not happen. After water-absorbing is completed and bricks appear to be dry, place a similar quantity of water in the dish and permit it to vaporize like above. Analyze the bricks for efflorescence after the second evaporation and report the outcomes.
From the above test evaluation efflorescence shall be reported as ‘nil’, ‘minor’, ‘medium’, heavy’ or ‘serious’ according to the following explanations.
- Nil: When there is no percentage deposit of efflorescence.
- Minor: When there is less than 10 percent of the exposed area of the brick is covered with a thin deposit of salts.
- Moderate: When there is a heavier deposit than under ‘minor’ and covering to half of the exposed area of the brick surface but unaccompanied by a powdering of flaking of the surfaces.
- Heavy: If the deposit of salts covering half or more of the exposed area of the brick surface but is unaccompanied by powdering or flaking of the surfaces this is heavy efflorescent.
- Serious: At the serious condition there is a heavy deposit of salts in the form of powdering and/ or flaking of the exposed surfaces.
Qualities of Good Brick
The essential requirement for building bricks is sufficient strength in crushing, regularly in size, a proper suction rate, and a pleasing appearance when exposed to view. It should be well burnt and need to a uniform red color.
The brick should have a uniform size and plan, rectangular surface with parallel sides and sharp straight edges.
The surface should not be too smooth to result in slipping of mortar and not proper bonding.
The bricks should be so hard that when scratched by a fingernail no impression is made.
When two bricks are struck together, a metallic sound should be produced.
Water Absorption should not exceed 20 percent of its dry weight when kept submersed in water for 24 hours.
Crushing Strength Should not be less than 10N/mm2.
Materials and Equipment used in Brick Masonry Work
Trowel is a bricklayer’s tool used for filling and shaping the mortar in between bricks. It has a triangular blade of around five inches in length, joined onto a handle made of either plastic or wood. Most of the mason like using short and wide trowels. So, they do not have to put extra stress on the wrist.
This tool is used for hammering nails and for splitting brick with the other end. One end is square and flat and is used as a hammer. The other end is sharp, like a small chisel. The sharp chisel-end is used to make a cutting line around the masonry to be split.
A Chisel is used to cut bricks into the required size. Chisel comes in a size ranging from 2.5 Inches to 4.5 Inches.
The brick jointer is used to apply a mortar finish to the beds and joints of a brick wall. It has a convex curve on either side and creates a “bucket handled” finish. Jointer comes in three different shapes Flat, rounded, and pointed.
Tape measure is used in the checking of profiles at the start of work and regularly used in the continuous checking in the requirements of bricklaying (windows and door heads).
The Squares are used for constructing and measuring right angles and corner layouts in Structure. They are generally made up of durable material for durability (Metal).
Spirit level is used, when setting up vertical or Plumb lines and horizontal or level lines. These are metal straight edges particularly fitted with glass tubes containing the single or double spirit and bubble of air. It is used for keeping brickwork upright and level.
This tool works as an ex-tensor to the spirit level. They are utilized when levels are shorter than the area that needs to be measured. A middle section of the top of the straightedge must be horizontally parallel to the bottom section.
Brick Masonry Procedure
Plan out the wall and arrange the exact amount and type of bricks. Using string, a level, and a measuring tape, layout the precise measurements of walls. There must include the mortar measurements when planning to construct a wall. The blend measurement of brick and mortar is called the brick’s nominal size.
Prepare all the materials (bricks, mortar, machinery & tools) that are required. When starting the work once mixed the mortar and start to lay the bricks, at the end of the day make sure to utilize all the mortar and strike the joints before quitting.
With the use of guideposts, we can ensure our wall’s level. To begin with, take 2 long wooden boards or posts and measure out each row of the brick wall, also named course. Mark the boards where each brick must be consisting of the mortar lines. It is necessary to make sure that we can drive the posts into the ground so that they can be freestanding.
Clamp a string on the first guideline and lay the first row of bricks for a dry run. Lay a small bed of mortar for the first brick to lay on and utilize the spirit level to make sure it’s level. Place a small amount of mortar on the top of the first bricks and place another brick on top of it at a downwards angle. Then lay a bed of mortar on the solid foundation for the wall. We can use the measuring tape to make sure that they are the correct distance apart and spirit level to make sure it’s flat.
Place the second mortar line alongside the first layer of bricks then start laying the second Bricklayer.
Use the two half bricks to start the second layer, to ensure that the first to a course are staggered for structural purposes.
To finish the second layer of bricks, lay the three header layer bricks and make sure that they are in level and Plumb. Then the third and fifth course includes stretchers similar to the first course. Then the fourth course begins with a single header followed by stretchers. Make sure you use the level to ensure the bricks laid are true on each course. Finally, this procedure of bricklaying is preceded until the target height is achieved.