I wish you a Very Happy New year Sir, My Heartfelt Thanks professor sir for your wonderful lectures and your efforts in making videos. Sir most of the members are discussing the design of pavements but very few videos are discussing the analysis of flexible and rigid pavement. Sir most of the students need an analysis of flexible and rigid pavement, please do that videos, sir. Sir, please share the presentation content material with all your subscribers then it will be very helpful to all the people. Thanks, sir.
First of all thanks to you for making such wonderful effort ....All concepts have been combined and compiled in a pot ...very informative and crisp videos covering all concepts 1. Sir how they have come to average axle value of 2.35 2. While calculating stress value from equation k value to be used should Be effective one (285) or earlier one 50.3 3.Sir plz if u could clarify point of design traffic for lateral placement of axles is 25% only 4. How we have come to point of percentage of various axles
Thanks for your comments. My reply is given here. 1. It is based on axle load spectrum data observed on Indian Highways over the time. Therefore it is an assumption only. 2. k value should be effective one. 3. The edge flexural stress caused by the axle loads for BUC is the maximum when the tire imprint of the outer wheel touches the longitudinal edge, and even a small distance of 15 cm from the pavement edge makes lot of changes in the stress. The typical lateral distribution of wheel paths of commercial vehicles observed on Indian Highways indicate that very few tire imprints of moving wheels are tangential to the longitudinal edge. Therefore this value is taken 25% (1 out of 4). Agarin a default value. 4. I think this point relates to Axle Load Spectrum data shown in one table. For each axle load class, there are ni vehicles. this ni is called the frequency (number of vehicles observed in axle load group i. Then percent frequency is ni divided by N (total number of vehicles weighed. I hope it is clear.
Greetings Professor! Very nice video on rigid pavement design example. I would recommend your videos. Could you please explain in detail how to obtain the "Expected repetitions (ni)" and "Flexural stress" in the given table for BUC/TDC. Thank you in advance!
Flexural stress is obtained through a set of equations (or charts) which are built in the Excel sheet provided with IRC code. Expected (or predicted) number of Repetitions for a load group is obtained from traffic count data. ni is the number of repetitions of a load group i for design period (6 hour day or 6 hour night). I hope it clarifies your doubt. No? Write again.
Question-- What is critical stress condition in rigid pavement according to IRC 58: 2015? Then what should be the answer pls reply and if you explain in video than please provide time stamp
The flexural stress due to the simultaneous application of traffic loads and temperature differentials between the top and bottom fibres of a concrete slab is considered critical for design of pavement thickness. It is explained at time stamp 17.08. Watch it. Next time, be a bit polite when you ask a question.
Sir Considering the saving of natural resource, can the rigid pavement be constructed over existing flexible pavement just by scarifying bitumen layer and laying gsb, dlc and pqc
Yes, it should be possible. White topping is permitted by IRC also. But what you asked is different from white topping. care should be taken based on the site condition. After scarifying black layer, the existing granular base may also act GSB for new pavement. Check for grading.
IRC:58-2015 charts/equations are valid for 3.5×4.5 m slabs only. Extension by 0.5-0.6 m is permitted for outer slab. For 9m paved width, if I want to provide 4.5×4.5 m slabs then how to design? New FEM analysis?
Respected sir I am working Asst engineer in govt sector pl make a complete design construction for white topping pavement using irc 58 which is will be more useful for us Sir thanks a lot I have learnt lot of basic concepts which helped me in designing of various roads in Karnataka
The question is not clear, I explained the design through Excel sheets only, The excel sheet gives you design traffic for bottom up and top down cracking analysis also, which I explained in slides. Please let me know if you need anything else,
Dear Sir, first of all I would to express my sincere thanks for the important and well explained video on pavement design, one thing that I would like to get your advice, is how to obtain the excel file. It is very important to learn.
You can download from this link. docs.google.com/spreadsheets/d/1_OWE91cPj1toV-nHnH7DEw4fmF9tBnuo/edit?usp=drive_link&ouid=104340323223105810378&rtpof=true&sd=true
In the case of bus terminal, the fatigue analysis is to be done for single axle and dual wheel axle. The axle load in this case does not vary much and therefore, number is important. You can carry out analysis for standard axles (in my opinion)
Sir, can the PQC thickness be reduced, incase in we are able to achieve higher flexural strength due to use of synthetic macro-micro fibres in the same concrete mix design. For example M40 grade concrete the 90 days flexural strength is 4.95MPa. With addition of fibres and admixture the flexural strength at 90 days has increase to 6 MPA. So while designing the pavement can we take this value.
Sir thank you for this video: What is the minimum thickness of RCC pavement & what is the maximum distance of expansion joint & transverse joint we may provided ?
Sorry, I do not have much knowledge of RCC pavements. But if reinforcement is being provided in a jointed pavament to control cracking then the pavement should be designed as per IRC 58 only.
Sir, I have a doubt. If a pavement is bounded with DLC and I provided a trial thickness that failed the cumulative fatigure damage criteria but the combined stiffness is more than the design stiffness requirement then what to do?
IRC 58 does not talk of monolithic pavements. If you change any geometry or conditions of the pavement structure, then the stress equations given in the code will not be applicable.
spacing between individual axles fir tandem and tridem axles varies from 1.3 m to 1.4 m and there is practically no difference in stresses for axle spacing between 1.3 m and 1.4 m. IRC 58 considers axle spacing of 1.3 m for calculation of stresses. Tridem and tandem axles are assumed to cause same stress in the slab during downward curling (BUC).
you can download from the following link docs.google.com/spreadsheets/d/1Qe7RAyZ4r3SdIRPDdfOtPXRwB9HWcstK/edit?usp=share_link&ouid=118387083302780581255&rtpof=true&sd=true
1. Yes, IRC code is silent over it and we should take the actual value obtained from the filed data 2. Yes, I thought of telling this in my video but avoided to avoid any conflict between 37 and 58. The charts given in IRC 58 are up to CBR of 7 % only. Beyond this u need to follow IRC 37 procedure. 3. agree 4. The excel sheet used to calculate fatigue damage has this option of choosing tied or untied shoulder and the analysis will change accordingly. Thanks for your comments.
IRC does not specify any upper limit as it will depend upon traffic volume and soil condition. Normally 30 - 32 cm thick slab is enough even for heavy loads. But it is to be designed,
No, I am giving it for free. You can download from here. docs.google.com/spreadsheets/d/1_OWE91cPj1toV-nHnH7DEw4fmF9tBnuo/edit?usp=drive_link&ouid=104340323223105810378&rtpof=true&sd=true
The part of the video where calculations using excel sheet are shown was made with the help of my scientist colleague in CRRI. I will see if I have these excel sheets in my system and share with you.
we follow IRC codes in letter and spirit and many of our students find it difficult to understand the procedure given in IRC code. This code is not understood correctly even by tutors. Thanks for your comment.
Thank you for the explanation and video, Professor. It was very clear.
download from here
docs.google.com/spreadsheets/d/1_OWE91cPj1toV-nHnH7DEw4fmF9tBnuo/edit?usp=drive_link&ouid=104340323223105810378&rtpof=true&sd=true
I wish you a Very Happy New year Sir, My Heartfelt Thanks professor sir for your wonderful lectures and your efforts in making videos. Sir most of the members are discussing the design of pavements but very few videos are discussing the analysis of flexible and rigid pavement. Sir most of the students need an analysis of flexible and rigid pavement, please do that videos, sir.
Sir, please share the presentation content material with all your subscribers then it will be very helpful to all the people. Thanks, sir.
Noted.
First of all thanks to you for making such wonderful effort ....All concepts have been combined and compiled in a pot ...very informative and crisp videos covering all concepts
1. Sir how they have come to average axle value of 2.35
2. While calculating stress value from equation k value to be used should Be effective one (285) or earlier one 50.3
3.Sir plz if u could clarify point of design traffic for lateral placement of axles is 25% only
4. How we have come to point of percentage of various axles
Thanks for your comments. My reply is given here.
1. It is based on axle load spectrum data observed on Indian Highways over the time. Therefore it is an assumption only.
2. k value should be effective one.
3. The edge flexural stress caused by the axle loads for BUC is the maximum when the tire imprint of the outer wheel touches the longitudinal edge, and even a small distance of 15 cm from the pavement edge makes lot of changes in the stress. The typical lateral distribution of wheel paths of commercial vehicles observed on Indian Highways indicate that very few tire imprints of moving wheels are tangential to the longitudinal edge. Therefore this value is taken 25% (1 out of 4). Agarin a default value.
4. I think this point relates to Axle Load Spectrum data shown in one table. For each axle load class, there are ni vehicles. this ni is called the frequency (number of vehicles observed in axle load group i. Then percent frequency is ni divided by N (total number of vehicles weighed. I hope it is clear.
Thank you sir.... For explaining it in simple way.
Sir, any thought on making video on US Corps of Engineers Airport Pavement? Design?
Not Really. But can do if you help me.
Greetings Professor! Very nice video on rigid pavement design example. I would recommend your videos. Could you please explain in detail how to obtain the "Expected repetitions (ni)" and "Flexural stress" in the given table for BUC/TDC. Thank you in advance!
Flexural stress is obtained through a set of equations (or charts) which are built in the Excel sheet provided with IRC code. Expected (or predicted) number of Repetitions for a load group is obtained from traffic count data. ni is the number of repetitions of a load group i for design period (6 hour day or 6 hour night). I hope it clarifies your doubt. No? Write again.
@@SatishIITR Thank you very much Professor. Got it.
@SAIMADHU KALLYPALLI SVNIT for BUC, it from 10 AM to 4.00 PM and for TDC, it is from 12 midnight to 6 AM.
So sad you are very underrated sir 😢
Why do you think so? I do not need any rating, dear
Superb!!!
Thanks a lot
Great sir.
Thanks, share with your friends also
Question-- What is critical stress condition in rigid pavement according to IRC 58: 2015?
Then what should be the answer pls reply and if you explain in video than please provide time stamp
The flexural stress due to the simultaneous application of traffic loads and temperature differentials between
the top and bottom fibres of a concrete slab is considered critical for design of pavement thickness.
It is explained at time stamp 17.08. Watch it.
Next time, be a bit polite when you ask a question.
dear sir
kindly prepare a video on overloading analysis for both Rigid and flexible pavement
It is already covered in three videos - Design of Flexible Pavements, Design of Rigid Pavements and Estimation of VDF. Please watch.
Hi Sir, this video is very useful, can you please share the excel sheet
sure
Sir
Considering the saving of natural resource, can the rigid pavement be constructed over existing flexible pavement just by scarifying bitumen layer and laying gsb, dlc and pqc
Yes, it should be possible. White topping is permitted by IRC also. But what you asked is different from white topping. care should be taken based on the site condition. After scarifying black layer, the existing granular base may also act GSB for new pavement. Check for grading.
IRC:58-2015 charts/equations are valid for 3.5×4.5 m slabs only. Extension by 0.5-0.6 m is permitted for outer slab. For 9m paved width, if I want to provide 4.5×4.5 m slabs then how to design? New FEM analysis?
Yes, You will have to carry out FEM analysis for this size of slab. Their behavior was not studied during development of IRC:58
Thank you for the clarification!!
Respected sir I am working Asst engineer in govt sector
pl make a complete design construction for white topping pavement using irc 58 which is will be more useful for us
Sir thanks a lot I have learnt lot of basic concepts which helped me in designing of various roads in Karnataka
It’s irc sp 76
will do soon. Thanks. Please ask your students also to watch these videos.
Yes, It is IRC:SP 76 for overlay design.
what are the latest concrete pavement design procedures?
Not many.
The video is really helpful sir. Can you please make a video on how to find design wheel or axel load using Excel sheet.
The question is not clear, I explained the design through Excel sheets only, The excel sheet gives you design traffic for bottom up and top down cracking analysis also, which I explained in slides. Please let me know if you need anything else,
Sir can u share excel sheet in description
Dear Sir, first of all I would to express my sincere thanks for the important and well explained video on pavement design, one thing that I would like to get your advice, is how to obtain the excel file. It is very important to learn.
You can download from this link.
docs.google.com/spreadsheets/d/1_OWE91cPj1toV-nHnH7DEw4fmF9tBnuo/edit?usp=drive_link&ouid=104340323223105810378&rtpof=true&sd=true
@@SatishIITR Dear Sir, many thanks indeed for your kindness, may God bless you and your family as always 😍
@@sokhengphai506 Thank you so much
Hi sir, how to do load calculation if the design is for bus terminal. Which wheel loads at what proportions should we take
In the case of bus terminal, the fatigue analysis is to be done for single axle and dual wheel axle. The axle load in this case does not vary much and therefore, number is important. You can carry out analysis for standard axles (in my opinion)
Thankyou sir
Sir, can the PQC thickness be reduced, incase in we are able to achieve higher flexural strength due to use of synthetic macro-micro fibres in the same concrete mix design. For example M40 grade concrete the 90 days flexural strength is 4.95MPa. With addition of fibres and admixture the flexural strength at 90 days has increase to 6 MPA. So while designing the pavement can we take this value.
Yes we can.
Sir thank you for this video: What is the minimum thickness of RCC pavement & what is the maximum distance of expansion joint & transverse joint we may provided ?
Sorry, I do not have much knowledge of RCC pavements. But if reinforcement is being provided in a jointed pavament to control cracking then the pavement should be designed as per IRC 58 only.
Thank you sir🙏
Welcome. please share the link with your friends also
Sir, I have a doubt. If a pavement is bounded with DLC and I provided a trial thickness that failed the cumulative fatigure damage criteria but the combined stiffness is more than the design stiffness requirement then what to do?
IRC 58 does not talk of monolithic pavements. If you change any geometry or conditions of the pavement structure, then the stress equations given in the code will not be applicable.
Thank you, sir. My question is Which cracking is more critical BUC or TDC?
BUC is more critical as it is not visible
Sir how to calculate of modulus kf subgrade reaction of combinef founfation please explain
It is taken from Table given in IRC code.
Why in BUC ..we don't consider tridem axle calculations?
spacing between individual axles fir tandem and tridem axles varies from 1.3 m to 1.4 m and there is practically no difference in stresses for axle spacing between 1.3 m and 1.4 m. IRC 58 considers axle spacing of 1.3 m for calculation of stresses. Tridem and tandem axles are assumed to cause same stress in the slab during downward curling (BUC).
Sir thanks for information.
Pls share the excel sheet.
Thanks
you can download from the following link
docs.google.com/spreadsheets/d/1Qe7RAyZ4r3SdIRPDdfOtPXRwB9HWcstK/edit?usp=share_link&ouid=118387083302780581255&rtpof=true&sd=true
@@SatishIITR Sir thanks for sharing the excel sheet.
Sir,
1. No. Of avg axles to be calculated from axle load survey and if value comes
1. Yes, IRC code is silent over it and we should take the actual value obtained from the filed data
2. Yes, I thought of telling this in my video but avoided to avoid any conflict between 37 and 58. The charts given in IRC 58 are up to CBR of 7 % only. Beyond this u need to follow IRC 37 procedure.
3. agree
4. The excel sheet used to calculate fatigue damage has this option of choosing tied or untied shoulder and the analysis will change accordingly.
Thanks for your comments.
What should be the max thickness of Topmost layer (concrete slab),,
IRC does not specify any upper limit as it will depend upon traffic volume and soil condition. Normally 30 - 32 cm thick slab is enough even for heavy loads. But it is to be designed,
Should that thick slab be above previous roads ground level,,?
Sir, I have a question that in temperature differential table except Assam none of the north east states are mentioned. Is there any reason.
All North Eastern states are to be taken in the zone of Assam only,
Sir Step 2 How can we get flexural strength?
Flexural strength of concrete is alway determined by testing of beams in bending
very nice sir ! Sir, can you tell how to find stress (kg/cm2) from charts
getting stresses from chart will require selection of an appropriate chart for the given design parameters. Nothing else.
Thank you sir, can I get Excel files
Will see if I have it
Sir how do we calcualte k value from effective CBR if effective CBR is 8%
Table is given in IRC code to obtain k value for a given CBR. This table is shown in this video also.
Sir for intermediate lane (5.5m) is it applicable Sir
yes. take the size of the slab accordingly
Sir
Excel sheet calculations are not visible,
Check again, there must be some network issue at your end. The video is clear. You may try with Hindi version of this video if the problem persists.
Thanku sir
Welcome. please share the link with your friends also
Sir, can you please share the PPT
I have not considered it so far.
@@SatishIITR Please consider it, sir, if possible through a Google Drive link.
@@SatishIITR Please consider sharing of the PPT sir..
R u selling this Excel sheet?
No, I am giving it for free. You can download from here.
docs.google.com/spreadsheets/d/1_OWE91cPj1toV-nHnH7DEw4fmF9tBnuo/edit?usp=drive_link&ouid=104340323223105810378&rtpof=true&sd=true
@@SatishIITR thanks for sharing
how could I access the excel??
They come with code.
Thankyou sir
Welcome. please share the link with your friends also.
Sir, can you please share ppt and Excel file ?
Excel files come with IRC code in a CD. I took help of one of my colleagues to get than part of video.
Sir please share the excel sheet
Ok, on your email only
@@SatishIITR Please sir to all crust design of rigid & flexible pavement
@@deepakrajput-yq5jo will see if I have in my folder
@@SatishIITR sir then what happened of crust design, did u get the same
285 mpa/m kaise aaya sir wahi jana tha bss please help.me.sir
For k value of CBR 50.3 MPa/m and for Subbase of 150 mm and DLC base of 150 mm, you can find k value from the tables given in IRC 58
50.3 mpa/m kaise aaya sir
For Effective CBR of 8 percent k value can be read from the table given in IRC 58. Interpolate the values linearly.
sir please share excel sheet
The part of the video where calculations using excel sheet are shown was made with the help of my scientist colleague in CRRI. I will see if I have these excel sheets in my system and share with you.
@@SatishIITR please sir share excel
Irc me Jo hai wo bataya sir....khuch bhi explain nahi Kiya irc chod ke
we follow IRC codes in letter and spirit and many of our students find it difficult to understand the procedure given in IRC code. This code is not understood correctly even by tutors. Thanks for your comment.