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WHAT IS SUNK SLAB AND WHERE IT USES?

WHAT IS SUNK SLAB?


It is also a one type of slab which is cast at a certain depth from the normal floor level. It is provided at the depth of 200 to 300 mm from the normal floor level.

WHY SUNK SLAB PROVIDED?


Sunk slab is used to provide some plumbing connection or conduits, utility ducts and waterproofing layer etc. And after placing this things it will be filled with sand or other light weight Material like coal, flyash blocks and empty pots but remember whatever you filled it should be a good in compression.

WHERE SUNK SLAB CAN BE USED?


Sunk slab can be used in following locations:-
     Bathroom/ toilet/ latrine/ wash area  etc.

WHAT IS INITIAL AND FINAL SETTING TIME TEST

INITIAL AND FINAL SETTING TIME TEST OF FRESH CONCRETE

AIM:- To determine the initial and final setting time of cement as per IS 4031- 1988.

PRINCIPLE:-  When cement is mixed with water to make a soft paste, It becomes gradually less plastic and finally becomes hard mass. The time to reach this both stage is termed as setting time of cement.
The setting time is divided into two parts, namely initial setting time and final setting time.

APPARATUS AND MATERIALS:-

The vicat apparatusOrdinary Portland cementBalanceStop watchMeasuring cylinder

PROCEDURE:-

INITIAL SETTING TIME

Take about 400 grams of cement.Add 0.85% of water and prepare the cement paste. P is the percentage of water for the standard consistency.Start the stopwatch when water is added to the cement to make a paste.Fill the cement paste into vicar mould within 3 to 5 mins.A needle of 1 sq.mm in cross sectional area and 50 mm long is attached and brought down to touch the surface of the paste and quickly released allowing it to sink …

WHAT IS SLUMP TEST

SLUMP TEST OF FRESH CONCRETE
AIM:- To determine the workability of fresh concrete by slump test asper IS 1199-1959.
PRINCIPLE:- Slump test is most common used test for measuring consistency of concrete. It can be employed either in laboratory or at field.
APPARATUS AND MATERIALS:-  Slump cone
It is a metallic mould in the form of frutusum of a cone with internal dimensions as follows: Bottom diameter - 20 cm Top diameter - 10 cm Height of cone - 30 cm The bottom and top ends of the mould are open, parallel to each other and right angle to the axis of cone. Tamping rod which have diameter 16 mm and length 0.6 m.Fresh concrete
PROCEDURE:- 
The internal surface of the mould is thoroughly cleaned and free from super flurois moisture and adherence of any old set concrete before commencing the test.The mould is placed on a smooth, horizontal and non absorbent surface.The mould is filled with concrete in 4 equal layers. Each layer is tamped with 25 strokes of tamping rod.After the top layer has been tam…

WHAT IS WORKABILITY OF CONCRETE

WORKABILITY OF CONCRETE

Fresh concrete or plastic concrete is freshly mixed material which can be moulded into any desired shapeThe diverse requirements of partial properties of concrete like mixability, stability, transportability, placebility, mobility, compactability and finishability are collectively reffered as a workability of concrete. So it is a composite property.


Factors affecting workability of concrete:

Water contentMix proportionSize of aggregateShape of aggregateSurface texture of aggregateGrading of aggregateUse of admixturesTime of transportationTempretureFollowing tests are performed to determine workability of concrete.

Slump testCompacting factor testFlow testVee bee consistometer testKelly bell test

STEPS TO BE TAKEN BEFORE DEMOLISH EXISTING BUILDING

STEPS TO BE TAKEN BEFORE DEMOLISH EXISTING BUILDING

As per IS 4130 - 1991

Before start sabotage check all the electrical connections should be disconnected.If there any gas line in building then separate it with water line, steam line and any other services.If old building was deteriorate by any fire incident then support the roof or slab of building with props and C sections.Don't dismantling the building at night time if there any residence.Provide some supports to nearest building to prevent any harm of their walls.If there any feasibility of damage of nearest building then it is imperative to evacuate it.During the demolishing, workers should wear safety accessories like helmet, goggles, gumboot, hang gloves etc.At the area of dismantling, install a notice that this area is prohibited to enter.next to the site of sabotage, close the movement of men and vehicles.If the building is more than 7.5 meter height and traffic can't be stopped then install side walk shed of 4 meter h…

HOW TO CALCULATE DRY VOLUME OF CONCRETE AND WHAT IS 1.54?

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HOW TO CALCULATE DRY VOLUME OF CONCRETE FOR CONCRETE WORK


For concrete calculation, we always multiply Wet volume (actual required for work after mixing) with 1.54 to get dry volume.
we take a example of concrete cube with dimensions 1m x 1m x 1m which means 1 cu.m wet volume. When we convert this wet volume into dry volume, the volume is increased by 54% of wet volume. ∴ Dry volume = Wet volume + 54% of Wet volume = 1 + (54/100) x 1 =1 + 0.54 = 1.54 cu.m
WHAT IS 1.54?

TOP TEN REQUIREMENTS IN CIVIL ENGINEER

THESE ARE THE TOP 10 CIVIL ENGINEERING REQUIREMENTSTO BECOME A SUCCESSFUL CIVIL ENGINEER:

1. TESTS OF BUILDING MATERIALS:A good civil engineer should have proper knowledge of different tests of building materials. Some important tests are listed below. Concrete test : slump test, compressive test, split tensile test, soundness etc. Soil Test: Core cutter test, compaction test, sand replacement test, triaxial test, consolidation test etc.
Bitumen Test: Ductility test, softening point test, gravity test, penetration test etc. 2. determine the SOIL type:Various soil tests are conducted to determine the settlement and stability of soils before starting a construction. So as a civil engineer, you should have enough knowledge of these tests which are performed at the site. 3. SURVEYING INSTRUMENTS usage:Usages of surveying instruments like the total station, theodolite etc is also a mandatory knowledge for every civil engineer. These instruments are used for marking and measurements. 4. indian STA…

HOW TO CALCULATE WATER CONTENT FOR 1 M³ M25 CONCRETE

HOW TO CALCULATE WATER CONTENT FOR 1 M³ M25 CONCRETEWe are know below details Consumption of cement per m³ Water-cement ratio.Grade of concrete is M25.
Cement required for 1 m³ of M25 grade concrete is 9.51 bags.( Standard data) As we know 1 bag of cement contains 50 kg of cement. ∴ 9.51*50 = 476 Kg of cement. our water cement ratio is 0.5. Remember the formula : W/c ratio =Water content /Cement content Or Water content= Cement content x W/c ratio Water content = 476 Kg x 0.5 = 238 Kg. We know, 1 Kg =1 litre So water content= 238 Kg. = 238 Litres Add 5% wastage of water during mixing, handling, ∴ Water content = 5×238/100 + 238 = 250 litres.

HOW TO CALCULATE LOADS ON COLUMN

TYPES OF LOADS ON COLUMN:Self weight of the column x Number of floors Self weight of beams per running meter Load of walls per running meter Total Load of slab (Dead load + Live load + Self weight) The columns are also subjected to bending moments which have to be considered in the final design. The best way to design a good structure is to use advanced structural design software like ETABS or STAAD Pro. These tools are leagues ahead of manual methodology for structural design, and highly recommended. In professional practice, there are some basic assumptions we use for structural loading calculations. FOR COLUMNS:Self weight of Concrete is around 2400 kg per cubic meter, which is equivalent to 240 kN. Self weight of Steel is around 8000 kg per cubic meter. Even if we assume a large column size of 230 mm x 600 mm with 1% steel and 3 meters standard height, the self weight of column is around 1000 kg per floor, which is equivalent to 10 kN. So, in my calculations, I assume self weight of col…

CHECKING FOR COLUMN SHUTTERING

Checking of Column Shuttering
Following checks of column shuttering should be carried out before column casting.

•Check the size of shuttering for column and it should be as per drawing.
•The column shuttering should be strong enough to take the pressure of fresh concrete and remain in position during concreting, particularly when vibrator is applied.
•To hold the concrete shuttering firmly in place with proper alignment, concrete starter called “kicker” should be cast before fixing the shuttering and of same concrete mix.
•The starter should be hard enough to fix shuttering around it. It should be atleast 4 inch height.
•Column formwork box or shuttering for column should be made of plywood sheets with required amount of wooden patties.
•Apply water-based shuttering oil on the shutter. It helps to get the good finished surface of the concrete. The shuttering oil enables the easy removal of column formwork after the concrete hardens. It also increases the numbers of shutter repetition,…

WHAT IS SAFE BEARING CAPACITY OF SOIL AND HOW IT CALCULATE?

SAFE BEARING CAPACITY


The capacity of the soil which allow to bear loads coming from the structure is called bearing capacity of the soil. The total load at the base of the foundation at which soil fails to bear load is called ultimate bearing capacity. By considering different failure conditions, the ultimate bearing capacity is divided by factor of safety and the resultant  value is called safe bearing capacity of the soil. There are many types of soils are present so we have to know the soil type before designing the foundation. It can be determine by different soil test.we have some values of safe bearing capacity for different type of soil which are given below.

Sr no Type of soil Safe bearing capacity
Cohessive soil
1 Hard and stiff clay of deep bed 440 KN/sqm 2 Medium clay 250 KN/sqm 3 Moist clay and sand clay mixture 150 KN/sqm

IMPORTANT COMMANDS IN AUTOCAD PART 1

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SOME VERY USEFUL COMMANDS IN AUTOCADL It can be used for making simple lines in the drawing.C It is the command used for making a circle in AutoCAD. PL This command can be used to make a Polyline in your drawing. REC This command will make a rectangle in AutoCAD. POL This command can be used to make a polygon with minimum of 3 sides and a maximum of 1024 sides. ARC As the name suggests, this command can be used to make an arc in AutoCAD. ELLIPSE As the name suggests, this command can be used to make an ellipse with the major and minor axis. REG This command can be used to make a region geometry in AutoCAD. CO This command is used to copy object(s) in AutoCAD. ARRAY Using this command you can make Rectangular, polar or Path array. TR This command is used for trimming a geometry. OP Using this command you can open options window which contains most of the settings of AutoCAD.