What is Brick?

One of the oldest building materials in the construction line brick continues to be the most popular and leading construction material because of durable, being cheap, and easy to handle and work with.

Clay bricks are used for building up interior and exterior walls, partitions, piers, footings, and other load-bearing structures. A brick is a rectangular shape and of a size that can conveniently handle with one hand.

Brick may be made of a mixture of sand or burnt clay of sand and lime or Portland cement concrete(PPC). Clay bricks are normally used since they are economical and easily available.

The length, width, and height of brick are interrelated as below:

1. Length of brick = 2 x width of brick + thickness of mortar
2. Height of brick = width of a brick

The size of a standard brick should be 19 x 9 x 9 cm and 19 x 9 x 4 cm When placed in masonry the 19 x 9 x 9 cm brick with mortar becomes 20 x 10 x 10 cm. However, the bricks available in most of the country still are 9″ x 4-i x 3″ and are known as field bricks.

The weight of such a brick is around 3.0 kg. (6.61 lbs) An indent called fog, 1-2 cm deep, is shown in as per below, the figure is provided for 9 cm high bricks.

The size of the fog should be 10 x 4 x 1 cm. (100 X 40 X 10 mm ) The purpose of providing frog is to generate a key for holding the mortar and so that, the bricks laid with frogs on top. Frog is not provided in 4 cm (40mm ) high bricks and extruded bricks.

Properties of Good Bricks

1. Good bricks are used for the construction of important structures. They should possess the following qualities
2. Bricks should be table-mounted, well-burnt in kilns, copper-colored, free from cracks and with sharp and square edges.
3. Bricks should be uniform in standard size and shape.
4. Bricks should give clear sound when struck with each other.
5. Bricks, when broken, should show a homogeneous and compact structure free from voids.
6. Brick should not absorb water more than 15 percent of the weight for first-class bricks and 15 to 20 percent by weight for second class bricks when soaked in water for 24 hrs.
7. Bricks should be sufficiently hard. Any impression should be left on the brick surface when scratched with a fingernail.
8. Bricks should not be broken into pieces when dropped flat at the hard ground height of one meter.
9. Bricks should have low thermal conductivity.
10. Bricks, when absorbed in water for 24 hours, should not show deposits of white salts when dried in the shade — dried in the shade.
11. The Compressive Strength of brick shall not be less than 55 kg/cm²

Sampling of Bricks

It is sampling a lot which shall contain a maximum of 50000 bricks. In case a consignment has to brick more than 50000 brick of the same classification, size, and manufactured under relatively similar conditions, it shall be divided into lots of 50000 bricks or part thereof.

Sampling from the stack shall be divided into a number of real or imaginary sections, and the required number of bricks shall be drawn from each section. Bricks in the upper layers of the stack shall be removed to enable units to be sampled from places within the stack.

The sample size for Visual / Dimensional Characteristics 

Table No 1.

The sample size for Physical Characteristics 

Compressive Strength, Water Absorption Efflorescence. Etc.

Table No 2.

Types of Tests On Bricks

1. Compressive strength of brick
2. Water Absorption test on brick
3. Efflorescence test on bricks
4. Dimension test on bricks

Test of Brick Compressive Strength (Compressive Strength of Brick)

Relevant is Code

Is Code 3495 part 1

Apparatus

Compression Testing Machine(CTM)

Compression testing machine use of compress of any material as per show riding. So we know how much load in this material.

Scale

The scale used in this test for length, birth & depth of brick.

Wooden Plate

This material used for one between brick both side. Because of the edge of a brick safe in CTM (Compression testing machine)

Prework Before Compressive Strength of Brick (Brick Compressive Strength)

Remove observed in the bed faces to provide both smooth and parallel faces by grinding. Immerse in the water at room temperature for 24 hours (1 Day). Remove the drain and the specimen out any surplus moisture at room temperature.

Fill all voids and all fog in the bed face flush with cement mortar (clean coarse sand, the cement of grade 3 mm down ).

Store under the damp jute bag for 24 hours (1 Day), followed by immersion in freshwater for 3 days. Wipe and Remove any traces of moisture.

Procedure Compressive Strength of Brick (Brick Compressive Strength)

Place the specimen with flat and smooth faces horizontal, and mortar filled face facing upwards between two sides 3 thick ply plywood sheets each of 3 mm thickness and carefully centered between plates of the testing machine.

Apply load uniform rate of 14 N/sq.mm. ( 140 kg f/cm2 ) per minute till failure occurs and notes the maximum load at failure.

Load at failure maximum load in brick at which to produce any further increase in the indicator read reading on the testing machine

Note:- Plywood sheets plaster of Paris may be used to ensure a uniform surface for the application of load.

Calculation of Compressive Strength of Brick (Brick Compressive Strength)

As below calculation of test report

Compressive test of brick N/sq.mm. (Kgf/ sq.cm.)

= (Maximum load failure in Kgf (N) / Average area of the bed faced in Sq.cm ( Sq.mm)

Conclusion of  Compressive Strength of Brick Units

Compressive strength of brick units varied from 4.3 to 6.9 MPa with an average of 5.7 MPa. The average modulus of elasticity was found to be about 3878 MPa., and bricks were found to be soft and weak compared to clay bricks.

Absorption Test on Brick (Brick Water Absorption)

Relevant is Code

1. Is Code 3495 part 2
2. Aim: To determine water absorption of the specimen by 24 hours immersion in cold water.
3. Scope: This procedure covers all relative activity for the project site.

Apparatus (Brick Water Absorption):

1. Weighing Balance

Weight machine for use for brick. Actual weight of the brick and after water absorption of brick weight calculation

Dry Oven

Dry oven use for Absorption test on brick.

Measuring scale.

The scale used in this test for length, birth & depth of brick.

Sample Preparation Absorption Test on Brick (Brick Water Absorption)

1. Dimensions shall be a measure to an accuracy of 1 mm of a test specimen
2. A dry specimen in an oven at temperature 105-1150C till it attains substantially constant mass.
3. the specimen to room cool temperature and obtain weight – M1

Procedure Absorption Test on Brick (Brick Water Absorption)

1. Immerse complete dried specimen in clean water at temperature 27+/- 20
2. Remove specimen after 24 hours and wipe out any traces of water with a damp cloth.
3. Weigh the specimen within 3 minutes after removing from water – M2

Calculations & Records Absorption Test on Brick (Brick water absorption)

% Water Absorption

= (M2-M1 /M1) x100.

Average of the results obtained shall be recorded. All results shall be recorded in the respective Format.

Efflorescence Test On Bricks

Relevant is Code

Is Code 3495 part 3

Apparatus for Efflorescence Test on Brick

Dry Oven

Dry oven use for Absorption test on brick.

Procedure Efflorescence Test On Bricks

Place the depth of immersion, the end of the bricks in the dish in water being 25 mm. Place the entire arrangement in a warm (for example, 20 to 30°C) well-ventilated room so that the specimens absorbed all the water in the dish. And the surplus water evaporates.

Cover the whole dish having the brick with suitable glass cylinder so excessive hat evaporation from the whole dish may not occur.

After the water has been absorbed, and the bricks appear to be dry, place the same quantity of water in the dish, and then allow it to evaporate as before. After the second evaporation, examine the bricks for efflorescence and report the results.

Conclusion Efflorescence Test On Bricks

Nil: When the deposit of efflorescence is imperceptible.

Slight: When the deposit of efflorescence does not cover more than 10 percent of the exposed area of the brick.

Moderate: When the deposit of efflorescence is more than 10 percent but less than 50% of the exposed area of the brick.

Heavy: When the deposit of efflorescence is more than 50 percent, but the deposits do not powder or flake away from the brick surface.

Serious: When the deposits are heavy and powder or flake away from the brick surface. The specifications limit the efflorescence to be not more than moderate (10–50%) up to class 12.5 and not more than slight (< 10 percent) for higher classes

Dimension Test On Bricks

Relevant is Code

Is Code 1077

Apparatus:

Measuring scale.

The scale used in this test for length, birth & depth of brick.

Procedure Dimension Test On Bricks

20 pieces out of selected pieces (Table No 1.) are taken and are laid flat as shown in Figure No.1

2 c Measurement of Hight 

Dimension Test On Bricks Figure No.1

 The tolerances (as per below) on the sizes of bricks are fixed by giving minimum and maximum dimensions, not on individual bricks but on batches of 20 bricks chosen at random.

1. For modular size
   1. length 3720 to 3880 mm (3800 ± 80 mm)
   2. Width 1760 to 1840 mm (1840 ± 40 mm)
   3. Height 1760 to I 840 mm (1840 ± 40 mm) ( For 90 mm high bricks)
      • 760 to 840 mm ( 800 ± 40mm) ( For 40 mm high bricks)
2. For non-modular size
   1. Length 4520 to 4680 mm ( 4600 ± 80 mm )
   2. Width 2240 to 2160 tum (2200 ± 40 mm)
   3. Height 1440 to 1360 mm ( 1400 ± 40 mm )
      • • ( For 70 mm high bricks )
      • 640 to 560 mm ( 600 ± 40 mm)
        • ( For 30 mm high bricks)

Twenty entire bricks shall be selected at random from the sample selected under 8. Loose particles, all blisters of clay and small projections shall be removed.

They shall be arranged upon a level surface successively as indicated in please above figure. 2C, 2B, and 2A in contact with each other and in a straight line. (As per Figure)

The overall (Stright Brick) length of the assembled bricks shall be measured with a tape, other suitable inextensible measure sufficiently (Electronic measurement tape) long to measure the entire row at one stretch.

Measurement by repeated application of short rule or measure shan’t be permitted. If, it is found impracticable to measure bricks in one row, the sample may be divided into rows of ten (10) bricks each which shall be measured separately to the nearest mm(millimeter). All these dimensions shall be added together.

Test on Bricks PPT

Common Burnt Clay Bricks Detail / Strength

Frequently Asked Questions (FAQ) about Bricks

What is a brick and why is it commonly used in construction?

A brick is a rectangular building material made of clay, sand, lime, or Portland cement concrete. It is popular in construction due to its durability, affordability, and ease of handling and workability.

What are the common dimensions of a standard brick?

A standard brick typically measures 19 x 9 x 9 cm or 19 x 9 x 4 cm. When placed in masonry with mortar, the size becomes 20 x 10 x 10 cm. In some regions, field bricks measuring 9″ x 4″ x 3″ are commonly used.

What materials are bricks commonly made from?

Bricks are commonly made from a mixture of sand, burnt clay, sand and lime, or Portland cement concrete (PPC).

What are the essential properties of good bricks?

Good bricks should be:

1. Table-mounted and well-burnt in kilns
2. Copper-colored, free from cracks, and with sharp, square edges
3. Uniform in size and shape
4. Capable of producing a clear sound when struck
5. Homogeneous and compact without voids
6. Water absorbent by no more than 15-20% of their weight when soaked for 24 hours
7. Sufficiently hard to resist scratching with a fingernail
8. Strong enough to not break when dropped from a height of one meter
9. Low in thermal conductivity
10. Free from white salt deposits after drying when soaked in water

What tests are commonly conducted on bricks?

Common tests include:

1. Compressive strength test
2. Water absorption test
3. Efflorescence test
4. Dimension test

How is the compressive strength of a brick tested?

The compressive strength of a brick is tested using a Compression Testing Machine (CTM). The brick is placed in the machine, and a uniform load is applied until the brick fails. The maximum load at failure is recorded to calculate the compressive strength.

How is water absorption in bricks measured?

A brick is dried in an oven and weighed (M1). It is then immersed in water for 24 hours, removed, wiped, and weighed again (M2).

Water absorption is calculated as a percentage using the formula: % Water Absorption=M2−M1M1×100\% \text{ Water Absorption} = \frac{M2 – M1}{M1} \times 100% Water Absorption=M1M2−M1​×100.

What is the purpose of the efflorescence test on bricks?

The efflorescence test determines the presence of soluble salts in bricks, which can cause white deposits on the surface. Bricks are partially immersed in water, allowed to dry, and examined for salt deposits, which are categorized as nil, slight, moderate, heavy, or serious.

How are brick dimensions tested?

Twenty bricks are randomly selected, laid flat, and measured as a batch. The overall length, width, and height are recorded to check if they meet the specified tolerances.

What are the typical compressive strength values for common burnt clay bricks?

The compressive strength of common burnt clay bricks can range from 3.5 to 35 N/mm² (35 to 350 kgf/cm²), depending on the quality and classification of the bricks.