Testing of Brick

IS 3495 part (I) = Compressive Strength Test
IS 3495 part (II) = Water Absorption Test on Brick
IS 3495 part (III) = Efflorescence Test on Brick
IS 3495 part (IV) = Warp age Test on Brick
IS 1077 = Dimensions Test on Brick


1) Compressive Strength Test.

Take 5 Brick as sample, Fill the frog with cement mortar of (1:3) proportion, Brick immersed in water for 3day so that mortar gain the strength.
After 3 days remove this brick for water and use for test, place in compressive test machine (CTM) and Apply the load of 14N/mm2/min.,till the fracture does not occur on surface.

➤Minimum compressive strength of brick = 3.5N/mm2 or 35 kg/cm2

Compressive strength in N/mm2  = Maximum load at failure in N / Average area of the bed faces in mm2  

2) Water Absorption Test.

For this test oven dry brick is taken and its weight is measured (w').
Brick is immersed in cold water for 24hr or hot water for 5hr,
After immersion brick there weight again measured  (w")

Water absorption, percent by mass = (w"-w')/w' *100 

Note:- 24 hours Test – IS code Recommended, 5 hours Test – CPWD (not recommended by IS code)

3) Efflorescence Test on Brick.

The brick are kept in 150mm dia dish and immersed in 25mm depth of water at room temp. after all water is absorbed or evaporation it is fill again till 25mm and make to be absorbed or evaporation.

Efflorescence reported as nil, slight, moderate, heavy or serious

Nil - <1%
Slight -  <10% (the brick is covered with a thin deposit of salts.)
Moderate - 10-50% deposit of salts. 
Heavy -  > 50% deposit of salts.
Serious -A heavy deposit of salts 

4) Warp age Test on Brick

5) Dimensions Test on Brick

For this test 20 bricks are randomly selected taken arrange in the w.r.t  L*B*H
Stack length are measured for (19*9*9)
permissible limits:-
length - 368cm to 392cm
width - 174cm to 186cm
height - 174cm to 186cm


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Size and Weight of Bricks.

composition of bricks.

harmful ingredients in bricks.

classification of bricks.

Brick Manufacturing.

Testing of Brick.

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Brick manufacturing

Brick manufacturing involves four stages

1. Brick clay/brick earth preparation.
2. Moulding of bricks.
3. Air drying of bricks.
4. Burning of bricks.

1) Preparation of brick earth Various steps involved in sequence are:
a. Unsoiling
b. Digging
c. Cleaning
d. Weathering
e. Blending
f. Tempering

2) Moulding
➧Hand Moulding:   a. Ground moulded
                                b. Table moulded
➧Machine Moulding

3) Drying
a. Natural drying
b. Artificial drying

4) Burning
a. Intermittent Kilns
b. Continuous Kiln

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Size and Weight of Bricks.

composition of bricks.

harmful ingredients in bricks.

classification of bricks.

Brick Manufacturing.

Testing of Brick.

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Classification Of Hydraulic Turbine

⚡️Impulse turbine

Energy available at inlet kinetic energy 

1)Pelton wheel Turbine 

●High head tangential flow turbine

●Note-  Casing is only to prevent splashing of water does not form in Hydraulic function in pelton Wheel Turbine

●Nozzle at end of penstock convert pressure energy into kinetic energy

●Bucket shape double hemispherical Cup or Bowl

●Hydraulic efficiency of pelton wheel will be maximum when the velocity of wheel is the half the velocity of the jet of water at inlet u=V1/2

●Angle of deflection of the jet through bucket 165°

●Jet ratio(m)= Pitch diameter of pelton wheel(D) /diameter of jet(d)

●Number of bucket (Z) = 15+0.5m

●Speed ratio (fi) =velocity of pelton wheel (u)/ velocity of Jet from nozzle(√2gh)
= 0.43 to 0.47

⚡️Reaction turbine

Energy at inlet kinetic energy + pressure energy

●To maximize the efficiency of reaction turbine angle of absolute velocity at outlet is 90°
i.e. Vw2=0

1) Francis turbine
●Old Francis =  Inward radial flow reaction turbine ( water flows from outward to inward )
● Modern Francis = Mixed flow reaction turbine (i.e. inward radial + Axial)

2) Kaplan & propeller
Axial flow reaction turbine

●Kaplan = Vanes are Adjustable
●Propeller = Vanes are fixed to the hub and they are not adjustable

Note - Servometer used to adjustment of runner blades

⭐️Draft tube 

 Tube or pipe of gradually increasing area is used for discharging water from the exit of turbine to the tail race
Always submerged in water below Tail race level

●Converts kinetic energy into the pressure energy
●To increase  the net head on the turbine
●It permits negative head

Turbine             Sp. Speed       Head         
--------------------------------------------------------                                                                     
Pelton
1)Single Jet         10-35            >250m
2)Double Jet       35-60

FRANCIS             60-300          30-250m

KAPLAN &.        300- 1000      <30m
 Propeller
---------------------------------------------------------

⚡️Specific speed of turbine 

Speed at which turbine runs when it is working under a unit head and develops unit horsepower
 (N√p)/(H^5/4)

◆Characteristic curves of hydraulic turbine
1)Main characteristic curve constant head
2)Operating characteristic curves constant speed
3) Muchel curve or Isoefficiency curve constant efficiency

Governing of turbine operation by which speed of turbine kept constant at all condition of working

⭐️Cavitation of turbine 

When pressure falls below below Vapour pressure

●Only reaction turbine and centrifugal pumps subjected to cavitation

●In reaction turbine cavitation may occur at outlet of the runner or at the inlet of the draft tube

●In centrifugal pumps cavitation occurs at the inlet of impeller of pump Or at the suction side of the pump

Note= When Thoma cavitation factor greater than critical cavitation factor cavitation will not occur


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Size and Weight of Bricks.

composition of bricks.

harmful ingredients in bricks.

classification of bricks.

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Classification of Bricks:

1. First class Bricks:

➤ These bricks are table moulded & they are burnt in kilns.

➤ These are thoroughly burnt & are of deep red, cherry or copper colour.

➤ Surface should be smooth & rectangular, with parallel, sharp & straight edges

& square corners.

➤ It should be free from flaws, cracks & stones.

➤ It should have uniform texture.

➤ No impression should be left on the brick when a scratch is made by a finger nail.

➤ Fractured surface of the brick should not show lumps of lime.

➤ Metallic or ringing sound should come when two bricks are struck against each other.

➤ First class bricks are recommended for pointing, exposed face work in masonry structures, flooring & reinforced brick work.

➤ Water absorption = 12.5% of its dry weight when immersed in cold water for 24 hours is allowed.

➤ Crushing strength ≥ 10 N/mm².

2. Second Class Bricks:

➤ These bricks have same requirements as first class brick except for the one’s listed below.

➤ These bricks are ground moulded & they are burnt in kilns.

➤ Small cracks & distortions are permitted.

➤ Second class bricks are recommended for all important or unimportant hidden masonry works & centering of reinforced brick & reinforced cement concrete (RCC) structures.

➤ Water absorption = 16-20 % of its dry weight is allowed.

➤ Crushing strength ≥ 7 N/mm².

3. Third Class Bricks:

➤ These bricks are ground-moulded & they are burnt in clamps.

➤ These bricks are soft & reddish yellow coloured.

➤ Produce a dull sound when struck with each other.

➤ These bricks are used for unimportant & temporary structures & at places where rainfall is not heavy.

➤ Water absorption = 25 % of dry weight is allowed.

➤ These have rough surface with irregular & distorted edges.

4. Fourth Class Bricks (Zhama Bricks):

➤ These bricks are over burnt & badly distorted in shape & size & are brittle in nature.

➤ Ballast of such brick is used for foundation & floors in lime concrete & road metal, because of fact that own burnt bricks have a compact structure & hence they are sometimes found to be stronger than even first class bricks.

see more topic 👇

Size and Weight of Bricks.

composition of bricks.

harmful ingredients in bricks.

classification of bricks.

Brick Manufacturing.

Testing of Brick.

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Harmful Ingredients in Bricks:

1) Lime Slaking :

➤ Due to lime slaking volume of brick increases and due to that cracking and disintegration is occurs.

2) Iron Pyrites :

➤ Presence of the Iron pyrites leads to crystallization and disintegration of bricks during burning due to the oxidation of these pyrites.

3) Alkalies :

➤ Alkali act as a flux during the burning of bricks but if it is in excess, it causes the bricks to fuse with each other thereby resulting in its twisting and warping.

➤ Presence of Alkalies also leads to efflorescence and staining in bricks.

4) Pebbles or Stones :

➤ Presence of stones and pebbles brick earth leads to the formation of weak and porous bricks, load carrying capacity of which is comparatively reduced.

5) Organic and Vegetative Matter :

➤ Presence of organic and vegetative matter helps in the burning of bricks but if they are left unburnt, it results in the formation of gases during the decomposition, which when escapes through the body of the bricks leads to the development of numerous voids, which results in decreasing of load carrying capacity of bricks.

see more topic 👇

Size and Weight of Bricks.

composition of bricks.

harmful ingredients in bricks.

classification of bricks.

Brick Manufacturing.

Testing of Brick.

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Composition of Bricks:

1. Silica (50-60%):

➤ Silica prevents the cracking, shrinkage and warping of the bricks, thereby imparts uniform shape to it.

➤ if it is in excess, it destroys cohesion between the particles, hence bricks become too brittle.

2. Alumina (20-30%):

➤ Alumina impacts plasticity to the brick earth so that it can be easily moulded in any designed shape.

➤ If it is in excess, it causes shrinkage and warping during the drying of the bricks and makes the bricks too hard during the working process.

3. Lime (4-5%):

➤Lime also prevents the shrinkage of the bricks

➤ If it is in excess, it causes the brick to melt during the burning thereby it results in loss of the shape of bricks.

4. Oxides of Iron (5-6%)

➤ Oxides of iron help silica and lime to fuse with each other, hence leads to the development of strength in the bricks

➤ It also imparts reddish brown colour in bricks.

5. Magnesia (1%):

➤ Magnesia also prevents the shrinkage in bricks and imparts yellowish tint in bricks.

see more topic 👇

Size and Weight of Bricks.

composition of bricks.

harmful ingredients in bricks.

classification of bricks.

Brick Manufacturing.

Testing of Brick.

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Size and Weight of Bricks:

Size of bricks

➤ Standard size or modular size of bricks = 19*9*9 cm

➤ Nominal size (with mortar) = 20*10*10 cm

➤ Traditional size of bricks = 9’’*4.5’’*3’’

➤ Conventional size of bricks = 23*11.4*7.6 cm

➤ Dimension of frog = 10*4*1cm

Weight of bricks

➤ It is found that the weight of 1 m³ of bricks earth is about 1800 kg. hence the avg. wt. of a brick will be about 3 to 3.5 kg.

see more topic 👇

Size and Weight of Bricks.

composition of bricks.

harmful ingredients in bricks.

classification of bricks.

Brick Manufacturing.

Testing of Brick.

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Test on concrete*

Compaction Factor Test

➤ This test is used for the concrete possessing very low workability for which slump test is not suitable.

➤ Principle of this test is based upon finding the degree of compaction achieved by the standard amount of work done by the concrete when allowed to fall from known height.

➤ This degree of compaction is represented in terms of compaction factor that represents the density ratio.

➤ Density of concrete obtained during test to the Density of fully compacted concrete.

Slump Test

•  This is most common method.
•  Frustum having top diameter 10 cm, bottom diameter around 20 cm, height of 30 cm.
•  Concrete to be tested in filled in the mould in four layers where each layer is compacted 25 no. of times with the help of rod.
•  Mould is removed immediately by lifting it in upward direction which causes the concrete to subsidize and the subsidence of the concrete is referred as slump which may also defined as difference of the height of the mould and the top level of the subsidize concrete.
•  Higher the value of slump, more is the workability.
•  This test is not suitable for the concrete which process either very high workability or very low workability.

IS CODES FOR BUILDING MATERIALS AND CONSTRUCTION

The following is that the list of a number of the IS code giving requirements for building materials:

• IS 269–1989. Specification for ordinary Portland cement.
• IS 455–1989. Specification for Portland slag cement.
• IS 516–1959. Method of tests for strength of concrete.
• IS 1123–1975. Method of identification of natural building stones.
• IS 383–1970. Specifications for coarse and fine aggregates.
• IS 432–1982. Specification for mild steel.
• IS 3495–1976. Gives specifications for building bricks.

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Size and Weight of Bricks.

composition of bricks.

harmful ingredients in bricks.

classification of bricks.

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Different Types of plot in hydrology

●Mass curve:- Plot of Accumulated Precipitation Vs Time.

●Hyteo-graph:- Plot of Rainfall intensity Vs Time.

●Hydro-graph:- Plot between discharge in stream & time in chronological order.

● Flow mass curve:- Plot between cumulative discharge, Volume & time in chronological order.

●Flow duration curve:- Plot of Stream discharge Vs percentage of time the flow is equalled or exceeded.

Highway Engineering

✨15th percentile speed:-
Lower safe speed limit
(To avoid conjection )

✨50th percentile speed:-
Median speed

✨85th percentile speed:-
Upper safe speed limit
(decided speed regulation on road )

✨98th percentile speed:- Design Speed for Geometric design