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DevilAVRT
DevilAVRT

DevilAVRT

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What is the object of pointing? Describe the operation of pointing.

  1. nikeetasharma

    nikeetasharma

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    nikeetasharma Guru

    Pointing :- It is the art of finishing the mortar joints in the exposed brick or stone masonry with suitable cement or lime mortar, in order to protect the joints from weather effects and also to improve the appearance of building structure. Pointing is a type of front of the house exposed finish onRead more

    Pointing :- It is the art of finishing the mortar joints in the exposed brick or stone masonry with suitable cement or lime mortar, in order to protect the joints from weather effects and also to improve the appearance of building structure. Pointing is a type of front of the house exposed finish on masonry work.

    Object of pointing :- The main object of the pointing is to maintaining the joints of the structures. Pointing being cheap can be adopted in places of low rainfall. Pointing gives resisting power to the bricks and stones used in construction towards weather conditions.

    Operation of pointing :-
    1. All the mortar joints (on the masonry face required to be pointed) are raked out by a special pointing tool to a depth of 15 to 20 mm, so as to provide an adequate key for the fresh mortar used for pointing.
    2. All the loose mortar and dust are removed by brushes.
    3. The joints and wall surface are washed with clean water, and then kept wet for few hours. The joints so prepared, are filled with suitable mortar with a small trowel.
    4. The mortar is well presses into the joints to form a close contact with the old interior mortar joints and all excess mortar sticking to the sides are scraped away.
    5. The finished pointing work is kept wet for about 3 days when lime mortar is used for pointing and for 10 days when cement mortar is used for pointing.

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fathima
fathima

fathima

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What is the purpose of soil sample soaked in water 7days in the CBR Test?

  1. nikeetasharma

    nikeetasharma

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    nikeetasharma Guru

    CBR test is done in construction materials laboratories to evaluate the strength of soil subgrades and base course materials. The purpose of soil sample soaked in water for 7days is to find out the strength of the sample after soaking continuously in water. The effective CBR should be 75% .

    CBR test is done in construction materials laboratories to evaluate the strength of soil subgrades and base course materials.

    The purpose of soil sample soaked in water for 7days is to find out the strength of the sample after soaking continuously in water. The effective CBR should be 75% .

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Gopal Mishra
Gopal Mishra

Gopal Mishra

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Can you tell me types of slabs? And how can we design them?

  1. aviratdhodare

    aviratdhodare

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    aviratdhodare

    Flat slab - Flat slab is minimum 8″ or 0.2m. Slab without drop and column without column head(capital). Slab with drop and column without column head. Slab without drop and column with column head. Slab with drop and column with column head. Conventional slab - conventional slab is 4″ or 10cm. 5″ toRead more

    Flat slab – Flat slab is minimum 8″ or 0.2m.

    1. Slab without drop and column without column head(capital).
    2. Slab with drop and column without column head.
    3. Slab without drop and column with column head.
    4. Slab with drop and column with column head.


    Conventional slab – conventional slab is 4″ or 10cm. 5″ to 6″ inches

    1. One-Way Slab
    2. Two-Way Slab

    Hollow core ribbed slab

    hollow core ribbed slab

    Hardy slab

    1. One way Hardy Slab
    2. Two way Hardy slab

    Waffle slab

    1. Triangular pod system
    2. Square pod system

    Dome slab

    dome slab

    Pitch roof slab

    Pitch roof slab

    Slab with arches

    arch slab

    Post tension slab

    post tension slab

    Pre tension Slab

    Low roof slab

    Projected slab

    projected slab

    Grads Slab/ Slab on grade

    slab with sand and concreteconcrete slab

    Sunken Slab

    sunken slab below ground level

     

    a) Effective span of slab:

    Effective span of slab shall be lesser of the two

    1. L = clear span + d (effective depth )

    2. L = Center to center distance between the support

    b) Depth of slab:

    The depth of slab depends on bending moment and deflection criterion. the trail depth can be obtained using:

    • Effective depth d= Span /((L/d)Basic x modification factor)
    • For obtaining modification factor, the percentage of steel for slab can be assumed from 0.2 to 0.5%.
    • The effective depth d of two way slabs can also be assumed using cl.24.1,IS 456 provided short span is 3.5m and loading class is <3.5KN/m2

    Type of support

    Simply supported

    Fe-250 – L/35

    Fe-415 – L/28

    Continuous support

    Fe-250 – L/40

    Fe-415 – L/32

    Or, the following thumb rules can be used:

    • One way slab d=(L/22) to (L/28).
    • Two way simply supported slab d=(L/20) to (L/30)
    • Two way restrained slab d=(L/30) to (L/32)

    c) Load on slab:

    The load on slab comprises of Dead load, floor finish and live load. The loads are calculated per unit area (load/m2).

    Dead load = D x 25 kN/m2 ( Where D is thickness of slab in m)

    Floor finish (Assumed as)= 1 to 2 kN/m2

    Live load (Assumed as) = 3 to 5 kN/m2 (depending on the occupancy of the building)

    Detailing Requirements of RCC Slab as per IS456: 2000

    a) Nominal Cover:

    For Mild exposure – 20 mm

    For Moderate exposure – 30 mm

    However, if the diameter of bar do not exceed 12 mm, or cover may be reduced by 5 mm. Thus for main reinforcement up to 12 mm diameter bar and for mild exposure, the nominal cover is 15 mm.

    b) Minimum reinforcement: The reinforcement in either direction in slab shall not be less than

    • 0.15% of the total cross sectional area for Fe-250 steel
    • 0.12% of the total cross-sectional area for Fe-415 & Fe-500 steel.

    c) Spacing of bars: The maximum spacing of bars shall not exceed

    • Main Steel – 3d or 300 mm whichever is smaller
    • Distribution steel –5d or 450 mm whichever is smaller Where, ‘d’ is the effective depth of slab. Note: The minimum clear spacing of bars is not kept less than 75 mm (Preferably 100 mm) though code do not recommend any value.

    d) Maximum diameter of bar: The maximum diameter of bar in slab, shall not exceed D/8, where D is the total thickness of slab.

     

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Komal Bhandakkar
Komal Bhandakkar

Komal Bhandakkar

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What is the substitute material of ballast at railway track?

  1. AdityaBhandakkar

    AdityaBhandakkar

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    What is the substitute material of ballast at railway track?

    Hi, Ballast types depend upon the traffic and spacing and size of ties. The following are the materials used as a substitute for ballast : Ballast is a base for rails that are made up of stone used to hold the railway track on its position when loading from the railway's impact on the railway track.Read more

    Hi,

    Ballast types depend upon the traffic and spacing and size of ties.

    The following are the materials used as a substitute for ballast :

    Ballast is a base for rails that are made up of stone used to hold the railway track on its position when loading from the railway’s impact on the railway track.

    • Now it is instead of stone a cement concrete ballast is used. It has a long life and High durability.
    • In ancient days, wood ballast was used.
    • Steel sections are also used as a ballast for railways tracks.
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Himanshu joshi
Himanshu joshi

Himanshu joshi

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What is difference between Tie Beam and Plinth Beam?

  1. nikeetasharma

    nikeetasharma

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    nikeetasharma Guru

    TIE BEAM :- The beam which connects two or more columns/rafters in a roof/roof truss or in any height above floor level is called tie beam. Tie beams are mainly provided in roof truss and at plinth level. These beams do not convey any floor loads and only act as length breaker for columns where theRead more

    TIE BEAM :-

    The beam which connects two or more columns/rafters in a roof/roof truss or in any height above floor level is called tie beam. Tie beams are mainly provided in roof truss and at plinth level. These beams do not convey any floor loads and only act as length breaker for columns where the floor height is unusually high.

    The main purpose of tie beam is to carry axial compression and to transfer the rafters load to the column. It also prevents column from buckling.

    PLINTH BEAM :-

    The beam which is provided at the plinth level is called plinth beam. In farmed structure, this beam is the first beam constructed after foundation.

    The purpose of plinth beam is to distribute loads of walls over the foundation and it also connect all the columns. It also prevents cracks from the foundation to the wall. It also avoid differential settlement.

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DevilAVRT
DevilAVRT

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What are the various causes of providing a cavity wall?

  1. nikeetasharma

    nikeetasharma

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    nikeetasharma Guru

    The various causes of providing cavity wall are as follows :- 1. Damp Prevention :- Cavity walls reduces the chance of moisture intrusion from outer leaf to the inner leaf and thus helps in keeping inside of the building free from dampness. 2. Thermal Insulation :- The air in the cavity wall acts asRead more

    The various causes of providing cavity wall are as follows :-

    1. Damp Prevention :- Cavity walls reduces the chance of moisture intrusion from outer leaf to the inner leaf and thus helps in keeping inside of the building free from dampness.

    2. Thermal Insulation :- The air in the cavity wall acts as a non-conductor of heat and hence minimizes the transmission of heat from the outer leaf to the internal face of the interior leaf. Thus, cavity walls help in maintaining the thermal insulation of a premise.

    3. Sound Insulation :- The air in the cavity acts as a cushion for absorbing sound. By building cavity walls, a premise may work as a sound proof zone as a large quantity of external noise gets absorbed within the cavity.

    4. Efflorescence Prevention :- As dampness is not allowed to penetrate the cavity, the inner leaf of the cavity, which is always a load bearing wall, is kept free from efflorescence effects.

    5. Economy :- According to ‘W. B. McKay’ (Author of Building Construction), building a 275 mm cavity wall costs less than constructing a 328 mm solid wall (which is of the minimum thickness if dampness has to be mostly avoided). This measuring data may vary from one place to another and on the specific climate of the construction site. One has to calculate the customized details before deciding the measurement of a cavity wall.

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dbnalawade
dbnalawade

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Thousands of engineering graduates from Indian universities are not employable as the education they receive is short of employable skills. What are the best skill-based courses for a graduate engineer to be employable?  

  1. aviratdhodare

    aviratdhodare

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    aviratdhodare

    There is not a simple answer to your question. It depends on what type of engineering you are studying. The best advice is to read some job advertisements for graduate engineering jobs. Note down what skills are requested. Some of these will be addressed by your engineering program. Other skills youRead more

    There is not a simple answer to your question. It depends on what type of engineering you are studying. The best advice is to read some job advertisements for graduate engineering jobs. Note down what skills are requested. Some of these will be addressed by your engineering program. Other skills you can build on the side. These include communication and collaboration skills.

    Engineers spend 60% of their time communicating and <20% of their time doing technical stuff. Your engineering program will do a very good job of developing your technical skills but it’s the social skills of collaboration that will determine your ultimate success in the workplace. So, work hard at all those group projects. Figure out what it takes to get everyone engaged. One day, this will be a vital skill in your workplace.

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