Friday, 12 July 2019
Friday, 29 December 2017
Slump Test
12:39 am
md faiz ali
The following tests are commonly employed to measure work ability.
(a) Slump Test
(b) Compacting Factor Test
(c) Flow Test
(d) Kelly Ball Test
(e) Vee Bee Consistometer Test.
Here we will discus about Slump test. Because slump test is one of the most important test while we are determining the work ability of concrete.
Slump Test :
Slump test is the most commonly used method of measuring consistency of concrete which can be employed either in laboratory or at site of work. It is not a suitable method for very wet or very dry concrete. It does not measure all factors contributing to work ability, nor is it always representative of the place ability of the concrete.
The pattern of slump is shown in Fig. It indicates the characteristic of concrete in addition to the slump value. If the concrete slumps evenly it is called true slump. If one half of the cone slides down, it is called shear slump. In case of a shear slump, the slump value is measured as the difference in height between the height of the mold and the average value of the subsidence.
Apparatus :
The Slump Cone apparatus for conducting the slump test essentially consists of a metallic mold in the form of a frustum of a cone having the internal dimensions as under: Bottom diameter : 20 cm, Top diameter : 10 cm, Height : 30 cm and the thickness of the metallic sheet for the mold should not be thinner than 1.6 mm Weights and weighing device, Tamper ( 16 mm in diameter and 600 mm length), Ruler, Tools and containers for mixing, or concrete mixer etc.
Procedure :
 Dampen the mold and place it on a flat, moist, nonabsorbent (rigid) surface. It shall be held firmly in place during filling by the operator standing on the two foot pieces. Immediately fill the mold in three layers, each approximately one third the volume of the mold.
 Rod each layer with 25 strokes of the tamping rod. Uniformly distribute the strokes over the cross section of each layer.
 In filling and ridding the top layer, heap the concrete above the mold before ridding start. If the ridding operation results in subsidence of the concrete below the top edge of the mold, add additional concrete to keep an excess of concrete above the top of the mold at all time.
 After the top layer has been rodded, strike off the surface of the concrete by means of screeding and rolling motion of the tamping rod.
 Remove the mold immediately from the concrete by raising it carefully in the vertical direction. Raise the mold a distance of 300 mm in 5 ± 2 sec by a steady upward lift with no lateral or torsional motion.
 Immediately measure the slump by determining the vertical difference between top of the mold and the displaces original center of the top surface of the specimen. Complete the entire test from the start.of the filling through removal of the mold without interruption and complete it within 2½ min.
 If a decided falling away or shearing off of concrete from one side or portion of the mass occurs, disregard the test and make a new test on another portion of the sample. If two consecutive tests on a sample of concrete show a falling away or shearing off of a portion of concrete from the mass of specimen, the concrete lacks necessary plasticity and cohesiveness for the slump test to be applicable.
 After completion of the test, the sample may be used for casting of the specimens for the future testing.
Slump Test 
measurement of slump test 
Observation :
 The vertical difference between top of the mold and the displaces original center of the top surface of the specimen ………… mm
 The pattern of slump is shown True Slump/Shear Slump/ Collapse Slump/Zero Slump.
Result :
The slump of concrete ……….. mm indicate Low/ Medium/ High Degree of work ability
Tuesday, 19 December 2017
Quantity of Cement, Sand & Aggregate
1:44 am
md faiz ali
Concrete Mix Design:
In order to calculate amount of cement, sand and aggregate required in 1m3 of concrete , you have to know about different grades of concrete. Based on strength Different grades of concrete is classified into M5, M7.5, M10, M15 etc., wheras M stands for Mix and the number behind M stands for characteristic Compressive strength(fck) of the concrete in 28 days when checked in direct compression test. Tthe ratio for M20 grade of concrete is 1:1.5:3 that mean 1 part of cement, 1.5 part of sand (fine aggregate) and 3 parts of aggregate (crushed stone) in volume and then batched for mixing. To know the Concrete Mix Design follow below:
Mix Design (M) = Cement: Sand :Aggregate
Different grades of concrete has different proportions as follows (Concrete Mix Design) :
As Per IS456:2000 the concrete of different grades has following proportions of Cement, sand and aggregate.
Grade

Proportion

M5

1:5:10

M7.5

1:4:8

M10

1:3:6

M15

1:2:4

M20

1:1.5:3

M25

1:1:2

M30

1:1:3

Calculation of Quantities of Cement, Sand and Aggregate in 1m3 of concrete:
Concrete Mix Design for M20 Grade Concrete:
Now let us consider M20 grade concreteAs per IS456:2000 M20 Grade concrete proportion is = 1 : 1.5 : 3
We have to add all the volume to know the total volume = 1 + 1.5 + 3 = 5.5
As we know that during concreting when we place wet concrete , it gets harden after certain standard time. Considering the same it had be decided upon by Civil design Engineers to take a factor of safety ranging from 1.54 to 1.57 to counter that shrinkage.
i.e volume of dry Concrete = 1.54 to 1.57 times Volume of wet concreteI am Assuming 1.57 as factor of safety
So total volume of concrete required is 1.57 Cum
Hence we require 8 bags of cement for 1 cum of concrete.
Detailed explanation for No. of bags required for 1 cum of cement
Sand usually consists of moisture content. It increases the volume of sand (bulking of sand).
For accurate calculation use dry sand or include the effect of bulking in calculation.
Hence we require 672kg of sand for 1 cu.m of concrete.
Density of aggregate may go higher if void spaces decreases. 5mm aggregate has more density when compared with 20mm size of aggregate
Hence We require 1326Kg of 20mm aggregate for 1m3 of Concrete
Amount of Water Required for 1m3 of Concrete:
For making concrete, required amount of water is added. Water quantity is depends upon the climatic factors and workability required. We generally maintain 0.350.50 of water cement ratio. Remember, above values may change according to the moisture content present in sand and aggregate.
Hence 200 Litres of Water is required for 1m3 of M20 Concrete
Summary: –
8 bags of cement required for 1 cu.m of M20 grade concrete.
672 kg of Sand required for 1 cu.m of M20 grade concrete.
1326 kg of 20mm Aggregate is required for 1 cu.m of M20 grade concrete.
200 litres of water is required for 1 cu.m of M20 grade concrete
Table for Quantity of Cement, Sand, Aggregate, Water required for Different grades of concrete :
COMING SOON
Friday, 12 May 2017
Calculate the quantity of Bricks for messionory work
10:15 pm
md faiz ali
First of all we should assume Mortar ratio {Cement + Sand (Thickness)}
 Suppose Mortar Ratio is 1:6 (cement=1, sand=6)
mortar thickness = 10mm
 Constants
Density of Cement = 1440 Kg/m^{3}
^{}
1m^{3} = 35.3147 ft^{3}
 Volume of Brick (Without Mortar) = 0.19 x 0.9 x 0.9 = 0.001359 m^{3}
 Volume of Brick ( With Mortar) = 0.20 x 0.10 x 0.10 = 0.002 m^{3}
Now We have to determine the total volume of wall for brick work.
 Vol of wall = height * length * thickness
To get actual volume of brick work. subtract the all window and door volume.
Then Total volume of Brick work / volume of brick (with mortar)
You will get accurate number of brick required.
As for example
Volume of door = Length × Height × Width
Volume of brick = Length × Height × Width
Finally we don almost calculations now
we have to find number of bricks required to build this wall.
As for example
Suppose i am having a 20cm thick wall with some dimensions. And there are a gate and window is also available in design. Then we have to find the number of bricks required to built this wall.
We need :
 Total volume of wall
 Volume of door
 Volume of window
 Volume of brick work
 Volume of brick
 Number of brick =?
Let’s start and
do all the calculation step wise.
STEP1
Total volume of a wall
= Length ×
Height × Width
13 ×
10 × 0.65617 ∵20cm=0.65617ft
We change width unit in to feet
85.3021 cft/ft^{3}
STEP2
Volume of door =
7 × 3.5 × 0.65617
We
don’t have width of the door so, to determine it’s volume we use width of wall
here.
16.07646
cft/ft^{3}
^{}
STEP3
Volume
of window = Length × Height × Width
3.5 × 3.5 × 0.65617
8.038 cft/ft^{3}
^{}
STEP4
Volume
of brick work = Total vol – (vol of door + vol of window)
85.3021 – (16.07646 + 8.038)
85.3021 –
24.11446
61.18764 cft/ft^{3}
^{}
^{}
STEP5
Volume of brick =
19cm × 9cm × 9cm
1539
cm^{3}
^{ }we^{ }have all above units in
ft^{3} so we have to convert cm^{3} into ft^{3}
0.054349
cft/ft^{3 without mortar}
Volume of brick with mortar = 20cm × 10cm × 10cm
2,000 cm^{3}
0.070629 cft
Number of
brick required = vol of brick work ÷ vol of brick
61.18764
÷ 0.070629
866.32
= 867 Bricks required
Thanks
^{}
^{}
Thursday, 16 February 2017
Sewage Treatment
9:23 pm
md faiz ali
What is sewage treatment :
Municipal waste water, including sewage, is treated in a multi step process before the treated water is released into the environment.
Why we do this :
 Water pollution can be reduced when water is treated.
 To control/recycle utility water.
The earth has an abundance of water, but unfortunately only a small percentage (about 0.3%) is even usable by humans. The other 99.7% is in the oceans, soils, icecaps, and floating in the atmosphere.
Earth contains as
Sea+Oceans = 96.5%
Ground water = 1.7%
Glaciers = 1.7%
Vapor+Air = 0.001%
Only 2.5% of this water is freshwater.
How to treat water to make usable :
 Source control.
 Preliminary treatment.
 Primary treatment.
 Secondary treatment.
 Biological treatment.
 Tertiary treatment.
What is waste water ?
Wastewater, also written as waste water, is any water that has been adversely affected in quality by anthropogenic (انسانی ) influence. Wastewater can originate from a combination of domestic, industrial, commercial or agricultural activities, surface runoff or storm water, and from sewer inflow or infiltration.
Types of waste water :
Waste water comes in three main types.
 Black water
 Gray water
 Yellow water
Black water
This is wastewater that originates from toilet fixtures,
dishwashers and food preparation sinks. It is made up of all the things that
you can imagine going down the toilets, bath and sink drains. They include
poop, urine, toilet paper and wipes; body cleaning liquids, anal cleansing
water and so on. They are known to be highly contaminated with dissolved
chemicals, particulate matter and is very pathogenic.
Gray water
This is waste water that originates from nontoilet and food
fixtures such as bathroom sinks, laundry machines, spas, bathtubs and so on.
Technically it is sewage that does not contain poop or urine. Gray water is
treated very differently from Black water and is usually suitable for reuse.
Yellow water
This is basically urine collected with specific channels and
not contaminated with either black water or gray water.
If the term "wastewater treatment" is confusing to you, you might think of it as "sewage treatment." Nature has an amazing ability to cope with small amounts of water wastes and pollution, but it would be overwhelmed if we didn't treat the billions of gallons of wastewater and sewage produced every day before releasing it back to the environment. Treatment plants reduce pollutants in wastewater to a level nature can handle.
Wastewater is used water. It includes substances such as human waste, food scraps, oils, soaps and chemicals. In homes, this includes water from sinks, showers, bathtubs, toilets, washing machines and dishwashers. Businesses and industries also contribute their share of used water that must be cleaned.
These objects and materials that are transferred together
with the sewage to the treatment plants, make the treatment work difficult and
cause substantial disruptions (رکاوٹ ) in the process and affect the effluent (دھار ) quality.
Source of waste water :
 Domestic.
 Industrial.
 Commercial.
 Agricultural activities.
Necessity or proper of waste water :
We consider wastewater treatment as a water use because it
is so interconnected with the other uses of water. Much of the water used by
homes, industries, and businesses must be treated before it is released back to
the environment.
If the term "wastewater treatment" is confusing to you, you might think of it as "sewage treatment." Nature has an amazing ability to cope with small amounts of water wastes and pollution, but it would be overwhelmed if we didn't treat the billions of gallons of wastewater and sewage produced every day before releasing it back to the environment. Treatment plants reduce pollutants in wastewater to a level nature can handle.
Wastewater is used water. It includes substances such as human waste, food scraps, oils, soaps and chemicals. In homes, this includes water from sinks, showers, bathtubs, toilets, washing machines and dishwashers. Businesses and industries also contribute their share of used water that must be cleaned.
 Fisheries
 Wildlife Habitats
 Recreation and quality of life
What is Sewage ?
Water that is discharged after home or industrial use, and
cleared away via a system of pipes leading to a waste water treatment plant.
For what purpose are sewerage systems required in the local
authority area?
To prevent pollution and hazards that potentially can cause
diseases, and to prevent ground water pollution.
As opposed to closed water systems that are not accessible
to the public, except when opening the
tap. The sewerage systems are open and allow the entry of various objects and
materials via lavatories (شوچالیوں) and other systems for discharging water after home or
industrial use.
Catchment of sewage :
A catchment is the area of land surrounding a dam and the
river that feeds it. Rain falling in the catchment area that isn't absorbed
into the ground runs into the river and dam. The quality of the water is
determined by how 'clean' the catchment area is. It is important that we take
care of our catchment areas, as good water quality is important for healthy and
successful communities.
While estimating the water demand some factors should be considered.
Population of forecast water :
Population is one of the most important factors for design of the water systems, so it should be estimated, so as to know the increasing demand and ensure continuous supply to them.
population data is obtained by previous records and the rate of increase is found out and this used for further analysis, which may be by using the methods described here.
Population data can obtained by using described below :
 Arithmetic growth method.
 Geometric growth method.
 Curve linear method.
 Decline growth method.
 Ratio growth.
 Logistic method
 Mathematically/Arithmetic growth method :
It is based on the assumption that the rate of growth of
population is constant. It means that the each year population increase by the
same increment.
dp/dt = Ka
Where, dp/dt is the rate of change of population.
Ka is the constant arithmetic increment.
Ka can be determine by finding the slop of the graph of population against time. The population in the future is thus estimated.
dP /dt ∝ P => dp
/ dt = Kg
where, Kg = Geometric Growth constant.
If P_{0} is the population at any time t_{0}
and P_{f} is the population at time t_{f} then,
∫P_{f} P_{0} dp/p = K_{g} ∫ t_{f}
t_{0} dt = Ln (P_{f}/P_{0} = K_{g} (t_{f}/t_{0})
=> Ln (P_{f}/P_{0} = K_{g} Δt
=> (P_{f}/P_{0} = (e) K_{g} Δt
and
P_{f} = P_{0} (e) K_{g} Δt
 Logistic method :
When the growth rate of population due to birth, death and
migration are under normal situation and not subjected to extraordinary changes
due to unusual situation like war, epidemics earth quakes and refugees etc.
Then this method is used:
According to this method
P = P _{sat} / (1+ e^{a}+ bΔt), where P _{sat}
is the saturation population, of the community and a, b are constants. P _{sat},
a and b can be determined from three successive census populations and the
equations are
P _{sat} = 2 P_{0} P_{1} P_{2}
 P_{1}^{2} (P_{0} + P_{2}) / (P_{0} P_{2}
 P_{1}^{2})
To know more about STP Step by step click HERE
To know more about STP Step by step click HERE
Estimation of water demand :
As for example:
 Type of area/city.
 Size of the area/city.
 Population of the area.
 Industries.
 Average daily water consumption.
 Maximum daily consumption.
 Maximum weekly demand.
 Fire water demand / fire demand.
Sunday, 12 February 2017
Steel bar weight calculation
3:51 am
md faiz ali
:WEIGHT CALCULATION FORMULA FOR STEEL BAR:
[1] For Round bar:
Weight in Kg = Diameter(mm) x Diameter(mm) x Length(meter) / 162.2
As for example: I have a steel rod of 8mm diameter with 1 meter length.
(8*8/162.2)*1
(64/162.2)*1
(0.394)*1
0.394
[2] For square and Rectangular bar:
Weight in Kg = Width(meter) x Thickness(mm) x Length(meter) x 7.85
Chat for round steel bars
DIFFERENCE BETWEEN WEIGHT AND MASS
In physics the standard unit of weight is Newton, and the standard unit of mass is kilogram. On Earth, a 1 kg object weighs 9.8 N, so to find the weight of an object in N simply multiply the mass by 9.8 N. Or, to find the mass in kg, divide the weight by 9.8 N.
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