Different Types of Clay Bricks employed in Brick Masonry Construction.

Different types of Clay Bricks employed in Brick Masonry Construction

Based on the producing method,Bricks are generally 

classified into 2 sorts. :-
1. Preserved or UN burnt clay bricks
2. Burnt clay bricks.
1. Preserved or UN burnt Clay Bricks :-
Sun-dried or UN burnt clay bricks are less sturdy and these are used for temporary structures. UN burnt clay bricks preparation concerned in three steps.

A. The preparation of clay.

B. Molding of clay bricks

C. drying. Of Clay bricks.
After molding, bricks are subjected to daylight and dried exploitation heat from sun directly. So, they're not that a lot of sturdy and that they even have less water resistance and fewer fireplace resistance. These bricks don't seem to be appropriate for permanent structure.
2. Burnt Clay Bricks :-
Burnt bricks are smart quality bricks however but they additionally consist some extent of defected bricks. So, burnt bricks ar classified into four sorts and that they are .
First class bricks.
Second category bricks.
Third category bricks.
Fourth category bricks.
First Class Clay Bricks :-
First class bricks are smart quality bricks compared to different categories. they're shaped by table-molding and burnt in massive kilns. So, these bricks contain customary form, sharp edges and swish surfaces. they provide terribly sweet sound once hit one another. they need terribly harder of broken bricks.

First Class Bricks - work Below.

Second ClassClay Bricks :-
Second category bricks are lightweight red in colors. Their form is slightly UN uniform . they need some cracks on the surfaces. they are doing not provides a sweet sound once hit to every different. the half of of broken is higher in compare to top quality brick. they'll be employed in super structure.

Second Class Bricks --Works below.

Third category Clay Bricks :-
Third category Bricks ar in flare red color or xanthous in color. Their strength is incredibly poor. they'll not be employed in super structure. the half of of broken bricks is over five attempt to terribly above initial & second category bricks.

Third Class Bricks --work Below 

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Manufacturing method of bricks :-

There are four totally different operations are concerned within the method of producing of bricks:
A. Preparation of clay. 
B. Molding.
C. Drying.
D. Burning.
1. Preparation of clay for brick manufacturing:-
Preparation of clay for bricks producing is finished in six steps: UN soilure of clay we'd like pure clay for the preparation of bricks. the highest layer of soil might contains impurities, that the clay in prime layer of soil concerning two hundred metric linear unit depth is thrown away. this is often known as unsoiling . excavation when the removal of prime layer, the clay is mamma out from the bottom and unfold on the plain ground. cleanup during this stage, the clay is cleansed of stones, matter etc. if great quantity of particulate is gift, then the clay is washed and screened. The lumps of clay are regenerate into powder with earth crushing rollers.
Weathering. The cleansed clay is exposed to atmosphere for softening. the amount of weathering could also be three to four weeks or a full time of year. Generally, the clay is mamma out simply before the time of year for larger comes. mixing If we would like to feature any ingredient to the clay, it's to be additional during this stage by creating the clay loose and unfold the ingredient over it. Then take tiny portion of clay into the hands and standardisation it up and down in vertical direction. This method is named mixing of clay. Tempering during this stage, water is additional to clay and ironed or mixed. The pressing are done by oxen or with feet of men for little scale .

Clay Bricks Making & Dying System in India.:-

Clay Bricks Dying System in Asian country :-

The damp bricks, if brunt, are seemingly to be cracked and distorted. thus the shaped bricks are dried before they're taken for subsequent operation of burning. For the drying the bricks ar arranged longwise within the stacks of breadth adequate 2 bricks, A stack consists of 10 or eight tiers. The bricks are arranged on and across the stock in alternate layers. All the bricks are placed on edges. The bricks are allowed to dry till the bricks are become animal skin onerous of wetness content concerning a pair of.

Burning of Bricks :-

Bricks are burned at extreme temperature to realize the strength, durability, density and red color look. All the water is removed at the temperature of 650 degrees however they're burnt at a temperature of concerning 1100 degrees as a result of the fusing of sand and lime takes place at this temperature and chemical bonding takes between these materials when the temperature is cooled down leading to the onerous and dense mass.
Bricks don't seem to be burnt higher than this temperature as a result of it'll lead to the melting of the bricks and can lead to a distortion and a really onerous mass once cooled which is able to not be viable whereas masonry.

Bricks may be burnt exploitation the subsequent methods:-

1. Clamp Burning.
2. Oven Burning .

Clamp Burning:-
Clamp could be a temporary structure usually created over the bottom with a height of regarding four to six m. it's utilized once the demand of the bricks is lower scale and once it's not a monsoon season. this is often usually quadrilateral in arrange whose shorter edge among the parallel sides is below the bottom so the surface raising perpetually at regarding fifteen degrees to succeed in the opposite parallel edge over the bottom. A vertical brick and dust wall is built at the lower edge to support the stack of the brick. the primary layer of fuel is set because the bottom most layer with the coal, wood and alternative domestically out there material like garbage and husk. Another layer of regarding four to five rows of bricks is set so once more a fuel layer is set over it. The thickness of the fuel layer goes on with the peak of the clamp.

After these alternate layers of the bricks and fuel, the highest surface is roofed with the mud therefore on preserve the warmth. hearth is lighted at the lowest, once the fireplace is started it's unbroken vulnerable by itself for one or 2 months and therefore the same period of time is required for the cooling of the bricks.

Disadvantages of Clamp burning:-

1· Bricks at the lowest are over-burnt whereas at the highest ar under-burnt.
2· Bricks lose their form, and reason could also be their declivitous downward once the fuel layer is burnt.
3· This methodology cannot use for the producing of an oversized variety of bricks and it's expensive in terms of fuel as a result of an oversized quantity of warmth is wasted.
4· It can't be utilized in monsoon season.

Kiln Burning:-

The oven could be a massive kitchen appliance used for the burning of bricks. Generally, coal and alternative domestically out there materials like wood, garbage etc may be used as fuel.


The type of Kilns :-
1. Intermittent Kilns.
2. Continuous Kilns.
Intermittent Kilns: -
These also are the periodic reasonably kilns as a result of in such kilns only 1 method will turn up at just once. numerous major processes that turn up within the kilns are Loading, Unloading, Cooling, and Burning of bricks.

There are 2 styles of intermittent kilns:-

1. Up-draught Intermittent Kilns
2. Down draught Intermittent Kilns

Down draught kilns :-

They are a lot of economical as a result of the warmth is used a lot of by moving the recent gases within the larger space of the oven. In up draught kilns the recent gases are free once they get up to chimney entrance.

Continuous Kilns:-

These kilns are known as continuous owing to all the processes of loading, unloading, cooling, heating, pre-heating crop up at the same time. {they are} used once the bricks are demanded in larger scale and in brief time. Bricks burning are completed in sooner or later, thus it's a quick methodology of burning. There are 2 well-known continuous kilns:
Bull’s Trench Kiln:-

The Bull’s trench oven (fig. below) consists of an oblong, circular or oval arrange form. they're made below the bottom level by excavating a trench of the desired dimension for the given capability of brick producing. This Trench is split typically in twelve chambers in order that a pair of numbers of cycles of brick burning will crop up at an equivalent time for the larger production of the bricks. Or it should happen that one cycle is applied at only once all told the twelve chambers by employing a single method within the 2-3 chambers at an equivalent time. The structure is under-ground therefore the heat is preserved to an outsized extent thus it's additional economical. Once the fireplace is started it perpetually travels from one chamber to the opposite chamber, whereas different operations like loading, unloading, cooling, burning and preheating going down at the same time.

Such kilns are typically made to own a producing capability of concerning twenty,000 bricks per day. the downside of this oven is that there's not a permanent roof, thus it's challenging to manufacture the bricks within the monsoon seasons.

Hoffman’s Kiln:-

The most distinction between the Bull’s trench oven and also the Hoffman kilns are:
1. Hoffman’s oven is Associate in Nursing over the bottom structure whereas Bull’s Trench oven is Associate in Nursing underground structure.
2. Hoffman’s oven have a permanent roof whereas Bull’s trench oven doesn't have thus it former is utilized in twelve months a year to manufacture bricks however later is stopped within the monsoon season.
3. Hoffman’s oven is usually circular in arrange and is made over the bottom. the entire structure is split into the twelve chambers and also the entire processes crop up at the same time like in Bull’s trench oven.

2. Molding of clay for brick producing :-
In the molding method, ready clay is mould into brick form (generally rectangular). This method is worn out 2 ways in which in keeping with scale of project.
A. Hand molding ( for tiny scale).
B. Machine molding ( for giant scale).
Hand molding of Clay bricks :-

During the method of bricks creating on atiny low scale the force is additionally low cost then we are able to opt for hand molding. The molds are in rectangular form fabricated from wood or steel that are opened at the highest and bottom. The longer sides of molds are projected out of the box to serve it as handles. If we tend to take sturdiness in thought steel molds are higher than wood molds. In hand molding once more there are 2 sorts and that they are.

A. Ground formed bricks
B. Table-molded bricks
Ground Shaped Bricks :-

In the method of ground molding of clay bricks, 1st ground ought to be leveled properly and sand or ash is spread over the plain ground. because of this the bricks will be simply removed .
Now place the wet mold within the ground and stuffed it with tempered clay and press onerous to fill all corners of the mold. the additional clay is removed with metal strike or wood strike or with wire from the highest surface of mold..
The Mold is then raised up and that we have raw brick up the bottom. And once more wet the mold by dipping it in water and repeat identical method. the method of dipping mold on every occasion to create bricks is named slop molding.
Sometimes, the within surface of mold is spread with sand or ash rather than dipping in water this is often known as sand molding . The mold removed simply during this method.
Frog mark of bricks square measure created by employing a try of pallet boards. Frog mark suggests that the mark of depth that is placed on raw brick whereas molding. The depth is also 10mm to 20mm.
Frog mark stats the trademark of producing company and additionally it's helpful to store mortar in it once the bricks is placed over one another in brick work method.
Table formed bricks :-
This method is comparable to ground molding method, however here the bricks on formed on the table of size 2m x 1m.
Ground molding is economical when put next to table molding.
Machine molding of bricks :-
The bricks needed square measure in lots of abundance, then machine molding is economical and additionally saves longer. Here additionally we tend to square measure having 2 forms of machines .
Plastic clay machines .
Dry clay machines .
Plastic clay machines This machines contain gap in rectangular form and after we place the tempered clay into this machine it'll embark through this opening. Now, the oblong strips setting out the gap square measure cut by wires to urge needed thickness of brick. So, these are known as wire cut bricks. currently these raw bricks square measure prepared for the drying method. Dry clay machines Dry clay machines square measure longer saving machines. we will place the integrated clay into these machines directly while not tempering. suggests that tempering is additionally tired this machine by adding some water. once the desired stiffness is obtained the clay is placed in mold and ironed onerous and well-shaped bricks square measure delivered. These square measure known as ironed bricks and these don't need drying they will directly sent to burning method.



Specification of Brick :-

A brick is little block of burnt clay with a size that may be control in one hand handily. Brick ought to be totally burnt, of uniform color, having plane rectangular faces, sharp straight, right angle edges.
· customary standard size of common building brick is 190X90X90 millimeter.
· the scale of a Non-Modular brick is 9"X4-3/8"X2-11/16" (229X111X70 mm).But it's such as 230X110X70 millimeter.
· the load of a brick is concerning three to four kilo.
Recommended Sizes of Clay Bricks :-
sort of Bricks-
traditional Size (mm)---200x100x100 millimeter
Actual Size (mm)----190x90x90 millimeter
Non -Modular Bricks
229x114x70 millimeter
230x110x70 millimeter
Main Characteristics of Clay Brick :-


Good bricks ought to be burnt totally in order that they become onerous and sturdy.
Satisfactory burning of the bricks is observed by onerous ringing sound once 2 bricks square measure affected along.
The bricks ought to have swish and rectangular shapes with sharp corners and uniform colors.
The bricks ought to be free from cracks, chips, warp age, giant particles of lime and organic matters.
Water Absorption of Clay Bricks :-
Average water absorption of bricks will be checked once twenty four hours of immersion in cold water and water absorption mustn't be quite two hundredth of its own dry weight.

Classification of Bricks as per water absorption :-
1. If water absorption is twenty nothing --------Good Quality Brick.
2. If water absorption is higher than twenty one quarter day %----------Medium Quality brick.
3. If water absorption is quite twenty five nothing ----------- Poor Quality bricks.
Raw Materials Checking for Clay Bricks :-
Sufficient samples of the planet offered should be tested to visualize if the soil is appropriate for creating of clay bricks and offered of excellent clay ought to be near to the operating places.
It ought to check properly the uniformity of composition of the soil. Mechanical composition of the soil could ideally ensure and complete the subsequent needs.
Class of Bricks :-
Water optical phenomenon by weight
Heavy duty bricks (special made)------Only 5%
First category------20%
Second category-----22%
Third category -------25%
The two a lot of forms of soil will be mixed  higher than needs if single soil doesn't confirm higher than specification. The mixed soil ought to be free from.
1. Gravel Coarse Sand.
2. Lime and Kankar particles.
3. Vegetable matters and roots etc.
Cost of Clay Bricks in India 2020:-
1. Price of top quality bricks take issue in numerous a part of India however it vary from Rs.5500.0/ one thousand Nos to Rs.6500.0 / one thousand Nos.
2. Price of second category clay bricks vary from Rs.5000.0 / one thousand Nos to Rs.5500/ one thousand Nos.
3. Price of third category bricks vary from Rs. 4000/ one thousand Nos to Rs.4500/ one thousand Nos.

Er. Ramesh Chandra