In this article Learn: tests for burnt clay bricks as per is:3495-1976,test for compressive strength,test for water absorption,Test for efflorescence.  Tests for  burnt clay bricks as per is : 3495-1976  tests for  burnt clay bricks as per is : 3495-1976. are described below:             1. Test for compressive strength. According to Tests for  burnt clay bricks as per IS : 3495-1976, Grind the two bed faces to provide smooth, even and parallel faces. Immerse the specimen in water at room temperature. Remove the specimen from water after 24 hours and drain out any surplus water at room temperature. Fill up flush the frog and all voids with cement mortar (1part cement and 1 part clean coarse sand of grade 3 mm and down), store under damp jute bags for 24 hours and then immerse in clean water for 3 days. Remove and wipe out any traces of moisture. Place the specimen between two…

DIFFERENT FORMS OF BRICKS Below are described a few important forms in which bricks are made in various shapes to suit the different situations in which they are used. 1. Ordinary bricks. These are ordinary bricks with rectangular faces and of standard size. 2. Perforated bricks. These bricks have cylindrical holes through their thickness (Fig. 2.11). It is done by pushing iron bars through the brick at the time of molding. The advantages and disadvantages of having such bricks are as follows:     Advantages. (a) These dry and burn more easily and quicker as the hot gases can penetrate them. (b)       Because of reduced weight these are easier to handle. (c)       Because of saving in clay more bricks can be cast out of the same quantity of earth. (c)       These are unfit to be used in hydraulic structures. These bricks should be free from cracks, flaws and nodules of…

In this Article Learn about: Burning of bricks,Clamp or Pazawah,Bulls trench kiln,Sequence operation of Bull's trench kiln, Advantages and disadvantages of Bulls trench kiln,Hoffman's Kiln,Advantages and disadvantages of Hoffman's kiln. Burning of bricks             After the bricks have dried in sun these are burnt in kilns to make them harder, stronger, denser, less absorbent and consequently more durable. The bricks are burnt either in a (i) Clamp or Pazawah; or (ii) Kiln-(a) Intermittent, (b) Continuous. Working of each one of them is described below.             1. Clamp or Pazawah. Basic working remaining the same there are various variations of it in use in different parts of India. Below is given a description of the one in common use in Northern India: A trapezoidal floor is prepared slopping upwards at an angle of 15° The shorter end is slightly in excavation while the wider end is…

In this article learn about : completion of Drying operation of moulded bricks,moulded bricks,drying of bricks,drying operation,drying bricks, drying operation of moulded bricks Drying operation of moulded bricks             Before burning of moulded bricks  it is essential that the bricks have dried and have become sufficiently hard to be handled and stacked in clamps or kilns without getting damaged. Also if the bricks have not com­pletely dried. then they are likely to get cracked and distorted when burnt in the kiln.* The following points are kept in view to ensure successful completion of drying operation. (i)        As soon as the moulded bricks become dry enough so that they do not get damaged on handling they should be turned on edge and left for a day or two more to further harden. In the initial stages of drying bricks should be protected from severe sun and winds as otherwise rapid drying…

Learn : Hand moulding,ground moulding and machine moulding of bricks MOULDING OF BRICKS Hand moulding,ground moulding and machine moulding of bricks             Giving the required shape to the prepared brick-earth is known as moulding of bricks. There are two different ways of doing it: (i) Hand moulding, and (ii) Machine moulding.  1. Hand moulding . Hand moulding of bricks is extensively used in India and the neighbouring countries. This could be done on ground or on table known respectively as Ground moulding and as Table moulding.  (a) Ground moulding. This method is adopted when a large and level area of land is available for the purpose. The area of land on which moulding is to be done is levelled, plastered smooth and sprinkled over with sand. (i)        To prevent the moulded bricks from sticking to the moulds either sand is sprinkled on the inner sides of the mould or the…

In this article Learn about: various operations involved in preparing brick earth,digging,weathering,blending and tempering. pug mill, mould, wooden mould, steel mould, PREPARATION OF BRICK-EARTH Following are the various operations involved in preparing Brick-earth.  Digging. If the area from where soil is to be taken is grassy or has other vegetation then the top layer (about 20 cm deep) is excavated and thrown away as it contains roots of vegetation and other organic matter. The excavated lumps of soil are broken. It is ensured that the soil is free from gravel, coarse sand, lime and kankar particles, vegetable matter etc. Weathering. Excavated soil, after the clods have been broken, is mixed with a little water and is left in heaps to weather for a period varying from a few weeks to as long as it can be left. This improves its plasticity and strength. To keep the soil wet water may…

FIELD TESTS FOR SOILS FOR BRICK MANUFACTURE : Clay for brick making is prepared differently in a rural environment – manually in small brick yards – and near towns and urban areas mostly in large-scale factories employing heavy duty machinery and equipment. Since modern clay works, quite often cannot satisfy the demand for brick and tiles, rural brick makers are increasingly playing an important role as suppliers and thus, are confronted with the demand for good quality fired clay products. Brick makers are faced with the challenges of producing bricks of satisfactory quality efficiently, economically and sustain-ably and with particular regards to mitigating environmental damage. TESTING PRINCIPLE There are three ways for checking the quality of soil. Before sending the soil to the laboratory the first is to test the soil sample using simple field tests that require no special equipment's. These tests are quite satisfactory but occasionally the results of…

In this article Learn about : Brick earth composition,{ clay(alumina), silt, sand}, functions of brick constituent (silica or sand, alumina, lime, magnesia, oxide of iron), harmful ingredients of brick  (lime, iron pyrites,Pebbles of stone and gravel etc, Alkalies, Reh or Kallar)  BRICKS EARTH             Composition. A good brick-earth should be such that when prepared with water it can be easily moulded, dried and burnt with out cracking or warping. It should contain a small quantity of finely divided lime to help in binding the particles of brick together by melting the particles of sand. A little oxide of iron should also be present which would give the brick its peculiar red colour and act in the same manner as lime.     A good brick earth should preferably conform to the following composition : Clay (Alumina)         20 to 30 per cent by weight Silt                              20 to 35 per cent by weight…

Learn : Bricks,Classification,Characteristics and its uses. (i)Sun-dried or Kacha bricks,(ii)Burns or Pucca bricks.(a)First class bricks (b)Second class bricks(c)Third class or pilla bricks, (d)Overburnt or Jhama bricks,Classification as per ISI. bricks as per ISI : 1077-1976,TABLE :  Classes of Common Burnt Clay Bricks BRICKS  Bricks are blocks of tampered clay moulded to suitable shapes and sizes while it is still in plastic condition, dried in the sun and burnt, if desired so as to make them more strong, hard and durable. Common building brick is not only one of the oldest but also the most extensively used material of construction. Popularity of bricks as a material of construction is because of their local and cheap availability, strength, durability, reliability and insulating property against heat and sound.    CLASSIFICATION Bricks are broadly classified into two categories. (1) Sun-dried bricks or kacha bricks or unburnt bricks, and (2) Burnt bricks or pucca bricks. While burnt bricks or…