87 responses

  1. apparao
    November 18, 2010

    RCC Slab Design very informative to me

    Reply

  2. krishnachaitanya
    December 13, 2010

    thanks its is very helpful.

    Reply

    • shujaat arain
      June 7, 2011

      how can we determine the strength of concrete after 28 days of pouring.

      Reply

      • BenzuJK
        June 17, 2011

        A concrete block or specimen is sent to the lab for testing the quality of the concrete. Load is applied on the concrete block after 28 days of curing to determine the crushing strength of the concrete.

        The strength of the concrete is calculated by dividing the maximum load at failure by the average cross sectional area of the concrete block or member.

        Reply

      • sambhaji
        July 19, 2012

        normally how many days should we water to slab? also how many days we should keep slab centering supports?

        Reply

  3. ajita
    January 4, 2011

    good information…..keep up the good work

    Reply

  4. hina
    January 28, 2011

    well done

    Reply

  5. nandini
    March 15, 2011

    its really very helpfull to us

    Reply

  6. Tom
    April 10, 2011

    Between the prefabricated concrete slabs and in situ concrete slabs, which is more widely used? Also which is more economical ?

    Reply

    • BenzuJK
      April 11, 2011

      Hello,
      In-situ concrete slabs are commonly used. They are a typical method of construction of RCC slabs. And ofcourse they are less expensive than the prefabricated or precast construction methods…

      Cheers!

      Reply

      • maju
        August 17, 2011

        hi mam ur working is very clearfully thank you mam

        Reply

  7. Diane
    April 12, 2011

    Very informative article on RCC slabs. Thanks
    Diane

    Reply

  8. Muhammad Qasim Khan
    April 13, 2011

    it realy Good 4 us

    Reply

  9. MD ROFIUL ALAM
    May 29, 2011

    For simply supported slab
    where as Room size of 3m X 4.5m
    As per direction of reinforcement, What type slab will come ? 1> one way slab 2> two way slab

    Reply

    • BenzuJK
      June 17, 2011

      Hello,
      Since the room dimensions are 3mx4.5m, two way slab would be perfect and safe. If the size of the room was 2mx4m, then you could have go for a one way slab.

      I hope I have made it clear.

      Reply

  10. Ajay Kumar
    August 18, 2011

    Which kind of slab we r using now a days. Pre tension or post tension, kindly tell me function of both

    Reply

    • BenzuJK
      August 20, 2011

      Hello Ajay,
      Post tension and Pre tension slabs are not in much use in India. The kind of slab construction that we use is cast-in situ RCC slab.

      Reply

  11. Maruti
    August 31, 2011

    very helpful information..

    Reply

    • BenzuJK
      September 1, 2011

      Thank you so much Maruti. Do keep visiting.

      Reply

      • murugan
        March 27, 2012

        Dear Benzulk,
        Nowdays the L&T construction go for post tension roof element , Did you know that?

        Reply

  12. fenitoghose
    September 11, 2011

    rcc beam designing

    Reply

  13. emmanuel okoroafor
    September 29, 2011

    i am civil engineering student rivers state polytechnic bori, while i was dabbling into the internet i found site more interesting and educative, please could assist me more in engineering mathmatics, like structral mechnics, engineering hydrology and structural calculation.

    Regards emma

    Reply

    • BenzuJK
      September 30, 2011

      Hello Emma,
      We shall definitely try and clear all your queries regarding Structural Mechanics.

      Cheers :)

      Reply

  14. dastu
    November 1, 2011

    good information

    Reply

    • BenzuJK
      November 12, 2011

      Thank you Dastu. Do keep visiting.
      Cheers:)

      Reply

  15. rahmat
    November 16, 2011

    hi
    wondering !!! for not replying my question about name of 5 type of slab?
    thanks

    Reply

    • BenzuJK
      November 28, 2011

      Hello Rahmat,
      Here are the names of different types of slabs based on different methods of construction:
      1) Cast in situ slab
      2) Prefabricated Slab
      3) Coffered Slab
      4) Flat Slab
      5) Post Tension Slab

      Reply

      • yashawanth
        July 26, 2012

        hello,
        please tell me how much % of steel saved in Post Tension Slab(PT) method compared to normal method.

        Reply

      • mahesh
        August 31, 2013

        how do we calculate cantiliver beam steel

        Reply

  16. Haroon pakistan
    January 24, 2012

    Hi,
    Dear sister it is very benifacial for the student.i admit and i proude of my nighbours(idian’s brothers and sisters) wich are taking intrest in to distribute the knowledge.after that sister what is cintiliwer beam and also its desiging?thanks and best wishes 4 u.

    Reply

  17. Sumit Dey
    January 26, 2012

    madam ,tnks fr this site …….

    Reply

  18. Alfred
    January 31, 2012

    hi,
    which type of advanced floor can be used for column spacings of 15m….i need it to be in rcc only…
    can folded plate be used for such spans?

    Reply

  19. Meer
    February 19, 2012

    Hello, I’m constructing a warehouse with basement and ground floor. we initially planned to do the RCC, but after completion of Basement floor, now we decided to use the pre-fabricated slabs for ground floor, because it is very economical (save 50%). size of hall is 110 x 80 ft. plz tell me some benefits of using prefab technology.
    Thanks

    Reply

  20. gunasekaran
    March 5, 2012

    how to know one way or two way slab

    Reply

    • BenzuJK
      March 7, 2012

      One way slab is generally rectangular in shape and two way slab is square in shape.

      The reinforcement requirements for a rectangular shaped slab and a square shaped slab is different. Depending on the span and shape of the slab, it is classified under one way or two way.

      Hope it is clear now.

      Reply

      • Rajinesh
        November 8, 2012

        two way slab need not be square itself in shape can be of rectangle also.
        In simple words lenght to width ratio of slab if it exceeds 2.0 its one way slab, if not two way slab.

        Reply

    • Mahmoud Heikal
      December 16, 2012

      r=(b*m1)/(a*m2)
      b = long direction
      a = short direction
      m1 = factor depend slab system in long direction
      m2 = factor depend slab system in Short direction
      if r > 2.0 , so the slab was One Way Slab
      if r =< 2.0 , so the slab was Two Way Slab
      if r = 1.0 , reverse the directions ( the short direction become the older one )
      ——————————————
      m1 & m2 determine from the following :
      1. if the slab simply supported , m = 1.0
      2. if the slab continuous from two sides ( in the same direction of study ) , m = 0.87
      3. if the slab is simply from side and continuous from other side ( in the same direction of study ) , m = 0.76
      ——————————————–

      Reply

      • Mahmoud Heikal
        December 16, 2012

        about the condition
        if r = 1.0 , reverse the directions ( the short direction become the older one )

        i just wrote it wrong , i mean if r < 1.0
        sorry for that

        Reply

  21. Amba
    April 9, 2012

    How do we consider a water tank of 2000 litres (sintex tank) in the design of a two way slab or One way slab? As a concentrated load or udl?

    I am planning to do an inverted T-beam designof a slab and place the water reservoir on those beams

    Reply

  22. gandhi
    April 10, 2012

    some of our civil engineers recomend not to fill any sand or pcc concreting below the coloumn footing (specialy for hard gravel soil type.is it okay?

    Reply

  23. gandhi
    April 11, 2012

    alternate question to my previous query—
    can the structural coloumn be rested on the natural gravel soil (hard ) without filling sand and pcc?

    Reply

  24. sulli
    April 12, 2012

    what kind of slab we use if the span is too larger for example 11mx17m

    Reply

  25. Omkar
    April 17, 2012

    hello,
    I am pg student. i am having my project work in scaffolding design and i dont have any material regarding designing standards of scaffolding and formworks so please guide me.

    Reply

  26. lalit
    April 21, 2012

    i am trying to design a slab spanning 25 feet X 19 feet. as a oneway with steel 10mm in short at 6″ c/c and 8 mm distribution at 8″ c/c plz guide me is it ok or not???????

    Reply

  27. ranjan
    April 30, 2012

    Hi, We needed to place a “safe” weighing 1600kg (700mmx700mmx1500mm) on 4th floor. Its a normal column building. Is it safe or should be avoided.

    Reply

  28. NIKHIL PAKWANNE
    April 30, 2012

    give me the information about various types & methods of cracks?

    Reply

  29. sarveshwar
    May 16, 2012

    a 40 ftx 4o ft roof to be creatted with end supported column. Provide me link for design methodology /link for coffer type of slab please .

    Reply

  30. Anant
    June 3, 2012

    awesome awesome awesome..u hav really summed it very well..it helped me a lot to do a quick recap of the rcc slab construction for my seminar.. :) thankz..

    Reply

  31. Abdul kaleem
    June 14, 2012

    Hello mam,

    what should be the minimum and maximum distance between columns to column

    Reply

  32. nadim
    June 25, 2012

    nice information its realy helpful 4 us.

    Reply

  33. dhivya
    July 30, 2012

    it is a good and helpful to all..thanks for dng this job.

    Reply

  34. ajay sharma
    July 31, 2012

    Dear mam, today fortunately I visited ur blog and found it quite informative. I request u to plz notify me new posts by email.thanx and regards. .Ajay sharma

    Reply

    • BenzuJK
      August 7, 2012

      Hello Ajay,
      I have added your email address in the RSS feed list. After you confirm the subscription, you will automatically receive all the new posts posted on the Civil projects blog.

      Cheers :)

      Reply

  35. Mustaqeem
    August 12, 2012

    I want to know about design of RCC members of residential as well public buildings.

    Reply

  36. d.ramachandran
    August 14, 2012

    hello BENZUJK madam, pl remember a 2 way or 1way slab is classified by the ratio of large span and short span .if the ratio increases 1.5 the slab is taken as two way and reinforcement must be designed by code method which gives coefficients for long and short span and the bending moments can be calculated depending on if they are fixed on 2 supports or continuous..the short span takes more load and for cornors for torsion spl square rods should be provided..thank you if you read with patience

    d.ramachandran.B.E(CIVIL)

    Reply

  37. Amani
    August 20, 2012

    Can you please assist me on the procedures for steel fixing of slab?

    Reply

  38. Ahasun Ali
    September 12, 2012

    rcc reinforcement design & detail drawing

    Reply

  39. baiju
    September 26, 2012

    In a villa construction with load bearing wall having a room size 4.15m x 5.18. could you please advise the reinforcement which I am planning is correct or not. The slab thickness 110mm with reinforcement 8mm@100mmc/c shorter span and 8mm @120c/c at longer span. I hope your valuable advise.

    Regards
    Baiju

    Reply

  40. Abdul kaleem
    September 29, 2012

    Hi,
    what will happend if we drop concrete from certain height.

    Reply

    • Abdul kaleem
      October 12, 2012

      Hello mam,
      1) what are the disadvantages of dropping concrete from certain height.
      2) what is the Initial and final setting time of cement.

      please respond me as early as possible.

      Reply

      • sharif
        October 23, 2012

        Abdul kaleem :
        Hello mam,
        1) what are the disadvantages of dropping concrete from certain height.
        2) what is the Initial and final setting time of cement.
        please respond me as early as possible.

        Reply

  41. Azura
    October 14, 2012

    How to identify long distance and short distance for ribbed slab / waffle slab .

    Reply

  42. kaife
    October 17, 2012

    what is technically given name for slabs using ribs and Thermocole / hollow block/ clay blocks

    Reply

  43. sharif
    October 17, 2012

    Hello
    I hope that you will be ok.
    What IS Clear definition of slab
    what is slab importance
    what is slab types(Materials)
    What is slab types(construction

    Reply

  44. Rajinesh
    November 8, 2012

    hello ma’am,i hope u r doin gud, few queries.
    i saw that roofing can be done by pouring concrete over the steel corrugated sheet, is der need for reinforcement,should we give neccesary support like i section r any at bottom, wat is da max load dat it can take n mix proportion dat can be used for concreting..plz help me out

    Reply

  45. Abdul kaleem
    November 18, 2012

    Hello mam,

    please give me the answer of request no : 46. I am eagerly waiting for ur answer so please check it and try to reply as early as possible.

    Regards,
    Abdul kaleem

    Reply

  46. Piyush Goyal
    December 7, 2012

    How much beam depth can be reduced by using a coffer beam?
    what type of beam is good for supporting a span of 12.5M X 10M?

    Reply

  47. imran
    January 1, 2013

    hello just i want to know why concrete cubes are taken during slab casting and wats the step if that concrete blocks failed to achieve required strength ? ..

    Reply

  48. murali
    January 13, 2013

    hai all.i want to know about steel details for raft foundation and slab details .for G+12 building,please help me

    Reply

  49. Gamnya Bagra
    March 1, 2013

    What are the sizes or diameter of reinforcement used in two way slab, ma’m?

    Reply

    • BenzuJK
      March 13, 2013

      Hello,
      The diameter of reinforcement used in two way slabs depends on the design of the slab. There is no standard reinforcement sizes for the two way slab.

      Check this out:

      Minimum Standards for Structural Design

      Cheers :)

      Reply

  50. adam cool
    April 29, 2013

    hi i am from ethiopia i want to know what is the main difference between waffle slab and ribbed slab? plse give me your advice as soon as possible

    Reply

    • BenzuJK
      July 26, 2013

      Hello Adam,
      Ribbed and Waffle slab are almost the same with a few differences.

      Ribbed slab has a thick top slabs with crisscross beam network below. The depth of the ribs (beams) is less than the depth of the beams in the waffle slab. The beams are deeper in waffle slab. Also, the top slab is comparatively thinner than the top slab in a ribbed one.

      Reply

  51. Atif nasir
    September 17, 2013

    Dear mam,
    What method I can used a checking the density of earth for sub-structure work.
    Pls mail me.

    Reply

    • BenzuJK
      October 22, 2013

      Hello Atif,

      You need a surveyor to do this.

      Reply

  52. vakimuddin
    October 31, 2013

    I want to knew Rcc modern technical term,&soil machenics deeply

    Reply

  53. Amjad
    January 17, 2015

    Any suggestions – steps to green roof?
    In Lahore got constructed 1500 sq ft
    1-RCC slab roof – lenter.
    2-Over the lenter slab completed a half inch layer of thin gravel + cement + Wapro chemical (water, heat resistant).
    3-Now going to spread a sheet of plastic.
    4-Then a 6 inch soil layer
    5-Then a layer of tiles an inch thick.
    What should be the next step?

    Reply

  54. Miss Thinn Thinn Hlaing
    February 19, 2015

    Thanks for your knowledge share.

    Reply

  55. [email protected]
    April 20, 2015

    sambhaji :
    normally how many days should we water to slab? also how many days we should keep slab centering supports?

    Amjad :
    Any suggestions – steps to green roof?
    In Lahore got constructed 1500 sq ft
    1-RCC slab roof – lenter.
    2-Over the lenter slab completed a half inch layer of thin gravel + cement + Wapro chemical (water, heat resistant).
    3-Now going to spread a sheet of plastic.
    4-Then a 6 inch soil layer
    5-Then a layer of tiles an inch thick.
    What should be the next step?

    Reply

  56. Abhilash mane
    April 25, 2015

    Very nice information
    good work

    Reply

  57. Awlad
    July 6, 2015

    Why more dia bars are good for pile reinforcement?

    Reply

  58. Edem
    July 8, 2015

    Very educative
    Thank you so much
    Can I get a guide to detailing of other structural members in a form of pdf

    Reply

  59. Mahendra gaddam
    September 26, 2015

    Up to 3.00mts slab culvert, I want to know the reinforcement details

    Reply

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