GATE 2025 Civil Score Booster-RCC | 3 hrs marathon | Sandeep Adari

hello my dear students welcome to IMS gate academy myself Sandi parari now my dear students as we are inching towards the gate exam people are worried about

the concepts or people might be worried about more about the revision part now my dear students by solving a particular questions you will get an idea on the

subject it might be any subject so by solving some critical problems the problems which will help you to revise your Concepts I'll be covering in this

session myself sandip adari I have 10 plus years of experience in the field of gate coaching and I've have trained more than 20,000 students now my dear

students here let me tell you honestly when you are preparing for gate exam learning phase already completed practice phase has already commed

completed so it is the time to test yourself so how do you test yourself and how do you analyze your mistakes so there should be a test Series where you

have to test yourself so we at imsg Academy are offering test series Plus at imsg Academy now my dear students in this test series plus we are providing

12 test series and we are also giving the gate question booklet which is an important tool for every successful student now let me tell you my dear students why G previous year questions

are important let me tell you when you are revising the concepts how the question can be asked in the gate exam realtime gate exam definitely the gate previous year questions plays a very

vital role in addition to this the test series plus let me tell you you should be accustomed to the virtual calculator you should be accustomed to the real time environment of the G exam or you

want to analyze your mistakes how your mistakes can be made into the rest strength all these analysis can be done in this test series plac by students and I don't want to waste your time and I

want to quickly go into the concepts so let me today discuss my dear students we are going to discuss the rainforce cement concrete what do you mean by rainforce cement concrete my dear

students the word rainforce itself is what make it stronger so as a civil engineer you should be strong in technical or structural analysis part

the rainforce cement concrete plays a very vital role now in RCC why do we use steel and concrete the people will be answering me steel is strong in tension

steel concrete is strong in compression but let me tell you the exact as a technical aspect or a student who has prepared for gate exam you should tell that the coefficient of thermal

expansion for both the materials is almost same that is the reason which made concrete and steel to be binded together to form the rainforce cement

concrete now let us understand what actually do you mean by analysis and design my dear students the design is nothing but Dimensions analysis is what

analysis is finding sheer force bending M dead load load combinations all these can be done in the analysis part so my dear students let us analyze a

structural part so whenever you are doing the rainforce cement concrete we have the structural aspect which is very important what is a structure is a group

of structured elements connected together what are the structure elements it is a slab it is a beam it is a column it is a footing but fooing is the entire

the base of the antire structure so let us understand the most important topic in today's session is the limit State method what

sir the first method I would like to discuss here is what my dear students limit State method now my dear students what do you mean by limit State method

it is a method of designing a structure based on structural concept of sorry based on statistical concept of safety and

probability of failure as a civil engineer we give highest priority to the safety and we should ensure economical

so my dear students previously we used to have working stress method but nowadays you name except in the water tank design or where you will not allow

the cracks in any other method you we usually follow the limit State method in India we follow is 456 in American and UK or Dubai you can say American code

they will follow but let me tell you to have a better understanding of RCC subject the is code plays a very vital role so what exactly limit State method

it is a method of Designing a structure based on statistical concept of safety and probability of failure now my dear students what do you mean by statistical

so if you are really interested students please share the session and if you are having any queries you are always feel free to ask in the chat box okay now when you talk about statistics it can be

mean Medan mode or standard deviation so we apply the principles of Statistics to understand the safety failure sir every structural element has different failure

a beam can fail in bending a column can fail in buckling or you can say my dear students a slab can fail in deflection col and footing can fail in Shear why we

take the design criteria as the important thing is we should understand what should be the preventive measures or what should be the best method to

adapt for the design now as point of gate point of view so what is limit State method it is the most appreciable method or you can say this is the most

insure method why because limit State method ensures my dear students let me tell you limit State method is ensure what sir limit

State method ensures what it ensures double safety my dear students the word double safety is a big term when it comes to the design why it

ensures double safety see my dear students in we are designing for higher loads what sir

we are designing for higher loads and we allow lesser strength what we do sir we allow lesser

strength we design for higher loads and we we allow lesser strength so let me tell you my dear students here what is

higher loads is if I take design load here FD design load can be written as load into partial safety Factor so usually factor of safety will more than

one so when I take design load it will be higher similarly when I take lesser strength if you take the design strength it will be strength upon partial safety

Factor so my dear students how it ensures double safety is it is allowing the higher load suppose you have to design for 100 kgs or 100 kilon you'll

be designing for 200 kilon but at the same time my dear students economical point of view also keep in mind and you allow the lesser strength what

exactly do you mean by lesser strength sir I can carry some 50 cages but you will tell that I can carry only 40 cages to ensure the safety this is how the

limit State method says that it ensures double safety now my dear students let us discuss the important aspects

okay if you take the factor of safety for concrete if I take the factor of safety for concrete my dear students con

sir see let me tell you RCC is a subject in civil engineering where the weightage in Gate exam might be four or three marks but once you are want to apply the

realtime applications in the Civil technical core job this RCC plays a very vital role or if you are working as a structural engineer or a design engineer

this RCC plays a vital role so let me tell you my dear students the concrete has the factor of safety is 1.5 what is the factor of safety for steel my dear

students what is the factor of safety for steel the factor of safety for steel is 1.15 so my dear students you will have a

proper doubt sir why the factor of safety for concrete is more why the factor of safety for steel is less the reason is very simple the reason is

quality control my dear students the steel is manufactured in a industry when I tell you the D of the bar is 10 mm it will be 10 mm because it is according to

the manufacturing in the industry whereas concrete requires manual attention or you require a skill labor or there can be a it is done in the

laboratory so there can be a uh errors or something so that is the reason the concrete might have the factor of safety more so my dear students the reason for

concrete to have more factor of safety the simple thing you can tell as a quality control if you are attending any interviews like L&T or tce or tataa

Consulting Engineers or shaur G poeni from your btech these are the quite common questions they ask you why the factor of safety for concrete is more the reason is simple the reason is the

quality control very good very good my dear students now my dear students let us see what are the assumptions what are the assumptions of limit State method

this ass assumtions are very important and let me tell you why do we assume some assumptions in your college we or in any branch or any concepts we assume

some assumptions the reason is simple we assume some assumptions to make the complex problem into a easy problem or if the number of unknowns are more to

make it lesser concept or we confin to lesser unknowns by using the assumptions topic now my dear students what do you mean the first assumption the first

assumption we have is the sections which remain in plane what my dear students sections which remain in plane before

bending what sir sections which remain in plane before bending remain in the same plane after bending sections which remain in

plane before bending before bending remain in same

plane remain in same plane this assumption is also called Bolis assumption okay sections which remain in plane before bending remain in

the same plane after bending so what does this assumption says I want the outcome of this assumption this assumption says that strain varies

linearly what does this assumption says my dear students this assumption says that strain varies linearly so whenever

you are analyzing the concepts using the LSM method you should have why strain varies linearly is the reason is this is

the Assumption or you can say this assumption as the Bolis assumption okay now my dear students let me tell you another important thing suppose if I

want to draw the stress strain curve for concrete okay let me draw this stress train curve for concrete stress strain curve for concrete and here also my dear students

it is you feel it is simple but always known quantity will be in x-axis and unknown quantity will be on y- axis let me tell you my dear students always you have this is simple but as an

engineering student you should know okay always known activity will be on x- axis okay because Y is a function of X so dependent quantity will be on y- axis

independent Quant will be on X AIS so if I write here strain and if I write here stress

okay now see students the stress trrain for concrete is rectangular parabolic what is the stress Trin curve for concrete the

stress strain curve for concrete is you can say rectangular parabolic this can be a objective questions okay in state level exams or anything okay now my dear

students here if you see the strain here it is 0.2 and here it will be87 sorry

035 and here you can say 45 fck how this are you getting my dear students the stress strain curve for concrete is what it is rectangular

parabolic sir actually there is a is code clause also it need not be parabolic it can be any shape but there is a class saying that if the test

results are satisfied sir let me tell you if anyone ask you what is the stress strength curve for concrete it is rectangular parabolic now they can ask

you what is the is the shape always to be parabolic according to as46 no it can be any shape but there is a clause that

if the test results are satisfied now similarly my dear students if you see there fck fck has been

reduced to 67 fck due to shape effect what sir fck has been reduced due to 76 67 fck due to shape effect because in

concrete we make different shapes in molding and all now this 67 fck if I take the design strength here strength

upon partial factor of safety so here it is how much sir 67 fck divided by what is the partial safety factor for

concrete it is 1.5 so so this will be equal to 446

fck this will be equal to how much sir 446 fck so my dear students how 446 fck came into picture this is how the turn

now similarly if you see the stress strain curve for steel stress strain Ker

I hope you are following students if you have any queries you can ask me in the chat box now what is the stress Trin curve for steel okay what is the stress Trin curve

for steel sir if you see Here My Dear students I hope you are following AMA okay as I told you stress will be on

what sir stress will be on y AIS strain will be on x x axis independent quantity on sir

you might be doing laboratory tests and all but this is the basic independent activity on xaxis dependent on Y axis if

you see this the graph will be somewhere like this okay now my dear students they can ask you this here if I take this is

fe250 grade of steel or here it is Fe 415 or sometimes you can call this as fe5 100 because this is for hys SD bar

you can say okay now see students we draw a dra offset here okay we drop a offset here

to make ensure that up to this point stress and strain varies linearly and this value is equal to 0.02 and if I take a drop a

perpendicular here this value will be equal to what sir strain as you know stress how is how much 87 FY sir you can

ask me how the 87 FY came there if you see the design strength of steel strength is how much sir you can say yield strength upon what is the partial

safety factor for steel it is 1.15 so this will be equal to 0.87 fi this will be equal to how much

sir 0.87 FY and here strain means as you know slope of stress strain curve is what sir what is the slope of stress strain curve it is nothing but the Ang

modulus so strain can be written as 0.87 FY by yes this portion now if they ask you what is the

maximum strain in steel sir maximum strain in concrete is how much 0.35 okay similarly now the maximum strain

in steel if I write here you can remember this sir two times it was was asked in Gate exam directly there is no other question asked sir directly if you remember this concept they have given

the yield strength they have given the grade of Steel and they have asked you so maximum strain in steel is equal to 87 FY

by es + 0.2 so what is the maximum strain in

steel 87 FY by es plus 0.2 am I cor wrong my dear students so remember the strain in steel depends upon the grade

of the steel that point please keep a note okay let me tell you my dear students what is the key take away from this the formula 87 FY by es plus 0.02

and let me tell you my dear students the grade of the steel will tell you or will affect the maximum strain now please listen carefully this is a practical

point point of view let me tell you if the strain in steel if the strain in steel is yielded to the maximum value

then we say that the steel is economically utilized what sir again I repeat the point my dear students if the strain in steel is yielded to the

maximum strain then we can say that that steel is most economically utilized why suppose see if you see grade of Steel

500 but in that you can have 415 also but if you use high strength steel it should be utilized but you we have other aspects also let me tell you under rainforce over rainforce we'll be

discussing but for now how can you say that a steel is economically utilized is if the strain in steel is yielded to the

maximum value then we say that it is the strain is then then we say that steel is economic utilized now this I'm pretty sure in this video I'm trying to say my

dear students 95% chances by this diagram which I'm trying to show you will get a question so what is actually here is singly

rainforce section so my dear students we have singly rainforce section what is a singly rainforce section let me tell you my dear students a single rainforce

section is nothing but a a beam a beam which is reinforced on a beam which

is reinforced on tension side what sir a beam which is reinforced on tension side is nothing but what sir a beam which is

reforced on tension side is nothing but a singly reforced section okay now my dear students let us understand the diagrams here just a second students

I hope you are following sir okay now see students this is the diagram this diagram came from the

assumptions what we have done what is the first assumption we have done sir sections which remain in plane before bending remain in the plane after bending says what strain varies linearly

so this is the Assumption so we assume Steel on where sir tension side only okay suppose my dear students if I take this as the width of the section as B

okay and if I consider this as what sir overall depth capital D and up to tension side we take it as what sir

effective depth D now my dear students what is the strain in concrete we said it is 0.3 35 and up to Parabola if you

remember I have told you this is 0.002 what is the value sir 0.2 and what is the strain in the this

side this is equal to 87 FY by es S Plus 0.2 so this is the strain right my dear

students suppose what is the stress here we have 446 fck now my dear students you what they can ask you what is tension

force sir tension force is nothing but what is force sir stress into area so tension force is given by the formula

0.87 FY a okay similarly my dear students where does the compression force acts sir C

the area of this stress block diagram the area will give you the compression force am I correct or wrong sir so this is the compression force and let me tell

you my dear students the distance between the point of application of compression and tension force we call it this as liver arm what we call Sir this

we call it as liver arm so my dear students so you should have an idea on this okay so if you want to take a screen screenshot or anything you can do that

okay now let me write down the important formulas here so if they ask you first compression force okay compression force is given by the

formula can anyone tell me sir can anyone write in the comment box compression force is nothing but

0.36 fck B into XU am I correct sir this is the compression force and similarly if I write what is tension

force what is the tension force sir we have tension force is nothing but 0.87 FY

a okay now my dear students they can ask you what is Liam what is Liam Liam is nothing but but D

minus 4 to XU what sir L arm is nothing but D minus point4 to XU okay here tension force is

0. fyst Sir see actually we'll find the

0. fyst Sir see actually we'll find the centroidal centroid distance here this is called this distance is nothing but

0.416 XU exactly means it should be 416 XU okay clear sir very good my dear

student now you can write here if they ask you moment moment can be written as compression force into

Lam or you can write it as for a balance section because compression force and balance or you can write it as tension force into

Liam now my dear students we also have limiting depth of neutral axis or you can say XU Max what is the formula for XU Max can anyone tell me

sir what is the formula for XX 0.

35 upon 87 FY es s + 0.00

55 so this is the formula into d or you can write XU Max by D now let me tell you my dear students very very

important thing X this was also a previous gate question XU Max by d means what sir limiting depth of neutral axis what is XX by D it is nothing but the

limiting depth of neutral axis here when I talk about the xum max by D what we call limiting depth of neutral axis it

depends only on it depends only on grade of Steel only very very important question in Gate

exam or any competitive exam XU Max by D depends on only what sir grade of Steel only if you see the Ang modulus of Steel is constant the here the only unknown

here if you see is FY remaining terms are all constant so my dear students please understand the XU Max by D is

given as is given as 0.35 upon 87 FY by es plus 0.02 and it is it depends only on grade of Steel now

my dear students please let me tell you one table here if you have Fe 250 okay these are the grade of Steels

and if you have Fe 415 grade of Steel and next we have Fe 500 grade of Steel now my dear students if I talk

about the X x max by D value what sir if I talk about the XU Max by D values for Fe 250 what is the value

sir 53 for Fe 41548 and for 50046 so my dear students you should

have an idea on the XU Max by similarly if you talk about the limiting moments sir similarly if I talk about

the limiting moments limiting moments is what my dear students here it is called 149 fck BD

Square okay here it is38 FC BD square and limiting moment

for Fe 500 grade is f33 f c BD s so my dear students have you observed one thing is when you increase the grade of the steel here the moment carrying

capacity means that sorry not moment carrying I should not say limiting moment is reducing clear my dear students as the grade of the steel is increasing limiting moment is reducing

is also reducing that is the one important observation and please write down this table because my dear students when you are solving under reforce

section or over reinforce section or balanced section these table will help you okay now see students this is also

another important thing what are the types of sections we have okay I'll tell you I'll write I'll be giving you the oral concept here because that is also

important what is the types of sections we have now my dear students when I talk about the types of sections first one we have is the balanced section what sir first one we have is

the balance section agree my dear students next one we have is the under rainforce Section next one what we have sir under reforce

Section and if you talk about the third one that is the over reforce section that is the over reforce section what

sir next one we have is the over INF for Section now my dear students thank you thank you PR sir uh when I talk about the different types of sections we have

balanced section what actually do you mean by balanced section very good Divya very good sir what do you mean by balanced section

here sir practically it is impossible to have a balanced section sir a balanced section is a section in which

the the amount of Steel provided to balance the section will be same so practically it cannot be possible then why do you assume the section to be

balanced we assume the section to be balanced to find the depth of neutral axis which is the critical aspect of the finding the limiting moment or moment of

resistance now my dear students we have under reinforced what do you mean by under rainforce underdogs if India is playing match against Pakistan with the class of verat

kohi and Rohit sha we can say that Pakistan are The Underdogs so why because under reinforce means you are providing something less Pakistan has very less team where it cannot play with

India so it has not that much quality so under reinforce means let me tell you my dear students the amount of Steel provided to balance the section is less

than the amount of Steel required are you getting my dear students again please write down this the amount of Steel required to balance the section

provided is less than the amount of Steel required so you require some x amount of Steel but in under rainforce Section you can say that as provided is

less than the limiting moment of steel or you can say that XU less than XU

Max okay you can say XU less than XU Max so my dear students these are the conditions now what could be the failure for balance section the primary failure

for balanced section is please write down this as a note students the primary failure condition for balanced section

is compression because it has 90 almost 96% of concrete when I talk about under rainforce the failure will be ins Ste

and the primary failure is due to tension sir as the failure is in steel we say that the failure is in steel but steel is a

what material ductile material as it is a ductile material it shows a clear sign of warning you see in your buildings when old building spalling of concrete

that I am feeling not well so the steel gets corroded or anything so practically we assume the sections to be under rainforce what is under rainforce sir

how much amount of Steel you are provided it will be less than the steel required to balance so obviously the failure is in steel but steel is a

ductile material it shows a clear sign of failure so all the Practical all the Practical sections are designed as under rainforce now my dear students when I

talk about the over rainforce the amount of Steel provided is more than the amount of Steel required so we can say that if I'm I

want x amount of Steel but you are providing more amount of Steel that means you are reducing concrete because concrete and steel should be 100% if you're increasing Steel by some five

concrete should reduce so the failure is in concrete in case of w reforce section so concrete is a brittle material my

dear students as concrete is a brittle material the failure will be sudden practically all the over reinforce section should be avoided this is the

basic principle for a structural engineer all the sections should be under reinforced because it shows a sign of failure all the war reinforce

sections are avoided because the failure is sudden here the primary failure is by compression here the primary failure is by tension here the primary failure is

by compression my dear student so you might understand what is under reinforce what is over rainforce and what is the balance section here the conditions is

what sir you can say that as is greater than as limiting here you can say that XU is

greater than XU is greater than XU Max my dear students so these are the conditions these are the conditions for

under reinforced or War reinforced please write down this student very good very good now now my dear students according to the is456 code what is the minimum

tension reinforcement what is the minimum tension reinforcement let me tell you my dear

students the minimum tension reinforcement is given by the formula a by BD is equal

to 85 by FY if they ask you in percentage you just multiply with 100 my dear student if they ask you in percentage this is the

important formula my dear student okay this is a very important formula for suppose if they have given you 500 we'll be solving that question also after a while after these Concepts I'll be going

to the problems also and what is the maximum tension reinforcement is what is

the maximum tension reinforcement is 4 percentile of gross area what sir the maximum tension reinforcement is how

much 4 percen of gross area now my dear students when I talk about gross and when I talk about net area when you talk about net area you

come across effective depth when I talk about gross area overall depth comes into picture these things which I'm telling please keep in note so my dear students this is the minimum tension

reinforcement and this is is the maximum tension reinforcement I hope you are clear okay now my dear students there is

a concept called cover sir let me tell you cover is provided to have a proper bond between concrete and steel why do we power why do we provide cover sir to

have proper bond between concrete and steel or to protect the steel from corrosion suppose if it is near to Sea Coast due to the alkaline nature the

steel get gets corroded very easily in this case my dear students we we what we do is we increase the cover depth cover

if it is suppose in mild we provide 40 mm in seee we provide some 80mm so to overcome the corrosion and let me tell you my dear students what actually do

you mean by cover here because there was a gate question on this my dear students we'll be solving that question also you should understand what is nominal cover

and what is effective cover okay now see students the distance from the centroid of the steel

to the extreme fiber what sir the distance to the from the centroid of the steel to the extreme fiber is known as what sir is known

as effective cover this is known as what my dear students this is known as effective cover the distance see my dear

students one second students if I considered here this is stir up okay the distance from the

outermost of the steel what sir sir please understand here what is nominal cover is the distance from

the distance from the outermost of the steel outermost this word itself is a huge meaning we'll be solving that means you have

to exclude the stup also so nominal cover means it is the distance from it is the distance from outermost of the

steel it is the distance from outermost of Steel to the extreme

fiber you have to exclude whatever the d of the steel okay please write down this students I hope you are clear okay I hope you are

clear clear students similarly my dear students let me tell you when I talk talk about sheer reinforcement when I talk about Shear

reinforcement sir I'll give you some steps to solve the problems on sheer reinforcement okay please keep the note

of the steps sir first step is we have toi we call T is called nominal sheer stess what is T sir nominal sheer stess

sir please try to respond and if you like the session you can share with your friends who are preparing for the gate exam so what is St St is nothing but the

nominal she stress which is equal to V upon BD what's sir TV is nothing but Vu upon BD what is Vu sheer

force what is BD section details okay my dear students now we have next one is

toi okay we can say permissible sharess okay sir next what is tousi permissible shess remember my dear students toi

value will be from the code is456 and also remember that toi is a function

of function of percentage of Steel and fck what is fck grade of concrete what is percentage of Steel Diva Can you tell

me what is the percentage of Steel it is nothing but a by BD into 100 what is it what is this sir

a by BD into 100 agree so my dear students the toi value depends on two functions means in the table in the is

456 you should go through the PT and the grade of the concrete similarly now my dear students if TV is less than

T what's sir if TV is less than toi what we do we provide what sir T less than to or we

should say like this when T is less than5 toi we say that it is no sheare reinforcement is required this is a very important no sheare

reinforcement is required my dear students when T is less than5 Toc no sheare

reinforcement now my dear students when T is greater than5 Toc and tv less than Toc in this condition we provide minimum

sheare reinforcement what is the formula for minimum sheare reinforcement anyone my dear students what is the formula for minimum sheare reinforcement anyone you

can write that ASV upon B into SV is equal to 0.4 upon 87

FY sir ASV is what area of the stups what is SV spacing of the stups what is SV my dear students spacing of the stups

so when TV is greater than5 Toc or tv less than Toc we provide the minimum Shear reinforcement agree my dear students okay

now when T is is greater than toi Next Step what I can say e when TV is greater than toi you should understand my dear

students Shear reinforcement is mandatory what sir when TV is greater than Toc you can say here that sheer

reinforcement is mandatory now sir already we are providing the minimum sheare reinforcement right my dear students

already we are providing the minimum Shear reinforcement so here design Shear force is given by the formula TV

minus to C whatever the extra shear stress into section Force into stress into area will be over the shear force and let me tell you my dear students if

I consider this as a beam we have the cover here and we provide the stups and remember according to the is 456

code according to the is 456 code usually the length of the crack what sir usually the length of the crack will be equal to effective depth D so my dear

students if I talk about the design Shear Force here here if I talk about the design Shear Force this is equal to

stress 87 FY stress into area that is what sir ASV okay stress into area into number of stups if I take this as

spacing between the stups as SV okay now my dear students D upon

SV now see students this is equation 2 this is equation 1 by equating one and two equations you can calculate the

spacings equating one and two equations equating one and two equations you can get calculate the spacing okay my dear students I hope you

are following now let me tell you here now see my dear students when TV is greater than toy Max

what sir when TV is greater than toy Max when T is greater than Toc Max we have

to redesign what sir when TV is greater than to C Max what we have to do we have

to redesign sir you can anyone justify can anyone justify when TV is greater

than Toc Max why we have to redesign what is the reason to redesign now see students there can be two chances of failure what sir there can be two

chances of failure one is the primary compress ression failure sorry let me tell you or you can say

Okay diagonal compression failure or you can say diagonal tension failure what

sir when a section is subjected to Pure Shear please write down this when a section is subjected to Pure hereare there can be two failures one is the

diagonal tension failure and other one is what sir diagonal compression failure and this was one of the gate question this was one of the gate

question my dear students and another one is what sir diagonal compression failure sir here what happened is see my dear students when I talk about diagonal

tension failure this tension failure is taken care by providing the steel this tension

failure is taken care by what sir by providing this tension by providing

steam but as I told you we cannot allow we cannot take care or we should not allow the diagonal compression

failure so let me tell you toi Max is a check for is a check for diagonal compression failure as we should not allow if it is more than that we we are

asking to redesign and remember my dear students toi Max is a function

of grade of concrete only sir whatever the theory points what I have told you these are all came in the previous year gate

exams okay so what is toy Max to Max is a function of grade of concrete only and remember my dear students to C Max is

written as 0.62 root fck K so this is also actually we get the values from code but if they can ask you

what is toy Max this is the formula okay clear students next let me tell you if I talk about the toy that is what's our nominal

shear stress we have talked about uniform section that is V upon BD but let me tell you my dear students for

varying sections what sir sir in two or five in 2 3 minutes I'll be going into the problems so okay as we required the concepts I've given you the early

Insight of the concepts so TV is equal to what sir

Vu plus or minus M by D tan beta upon BD

this is the formula for nominal shest my dear students okay sir see here you should understand when you will go with

positive sign and when do you go with negative sign sir see if the varying depth if the varying

depth increases okay if the varying depth increases and also M increases upward arrow is for increase

if the varying depth increases and M increases we use negative sign and the vice versa of it will will be what sir positive the vice versa of it will be

what positive agree sir so Here My Dear students if I take here a can section let me tell you suppose if I have taken a

if I have taken a c l section here okay now see students in c section what is happening ama if you see the moment

is maximum where where is the moment maximum the moment is maximum at where the moment is maximum at fixed

end but if you see the depth here if you see the depth depth is also maximum here in this case we use negative sign similarly my dear students if I take a

simply supported beam here okay now see the bending moment diagram will be like this right so here more

depth the bending moment is less M less depth more so in this case you will use

positive side so you should be aware of this things students okay I hope you are clear one second okay now I'll give you the timer amama

you have to see that questions these questions you should be solving I'll give you 2 minutes for every question and please try to solve that okay

okay please read the question for students please read the question here okay I've given you enough time Mama now let me read the question my dear

students the question here is the singly rainforce concrete beam of made up of M25 concrete and fe500 grade of

Steel the total cross-section area of Steel is how much sir 945 mm Square as per the limit State Design the design M

capacity of the beam section is what sir is asking the design moment okay so he's asking what is the design moment so to

find out the design moment okay first we'll calculate compression force is equal to tension force what we'll do sir compression

force is equal to tension force what will be the compression force 36 F CK B into XU and what is the tension force we have

sir what is the tension force can anyone tell me tension force is nothing but 87

FY as yes or no my dear students What is the compression force we have 36 f c

bxu what is the tension force we have 87 FY as now my dear students if I want to know the depth of neutral axis X is

equal to 87 f y a upon

36 fck into B yes or no please write down that students so here what is the grade of Steel Amma

here the grade of Steel is 500 area of Steel is how much my dear students what is the area of Steel 945 area of Steel is how much sir

945 and what is the grade of concrete we have I think M25 right sir see my dear students whenever you are solving the Gade questions you should write the

given data the here it is how much sir M25 and what is the width of the section here they have given the width of the section as how much 300

mm now please calculate that value and tell me sir what is the XU value so if you calculate the XU value you might get a value of

15176 mm what is the depth of neutral axis you might get you get a value of 151.50 7 sir most of the students do

this mistake am let me tell you what is the mistake whenever you finding the depth of neutral axis you should always

compare with the value of x max because you cannot assume that it is always less than if it is more than then

it is a overin for Section so here you should have a understanding okay now see now what is xum Max sir what is the

grade of Steel I told you the table it will be helpful Fe 500 right now in fe500 what is the xum max value 46d when

I'm explaining the concepts I have given you this 0.460 so what is D here sir effective depth is

450 so 46 into 450 so it 50% is 225 225 - 18 you will

get a value of 207 mm what is the value of XU Max sir you get a value of 27m so my dear students you are evident

or clear that XU is less than XU Max when you are evident or clear that XU less than XU Max we say that the section

is under reinforced so no need to limit the depth of neutral axis so my dear students when they ask you what is the design moment

here what is the moment you can write here 36 fck bxu into D

minus 42 XU okay my dear students okay now here what is the grade of Steel sir sorry

concrete it is 25 width of the section is 300 mm XU is how much my dear students XU is nothing but 151.90 into D is how much sir

450 minus 0.42 into XU is how much sir 151 151 76

mm so if you solve this what is the limit what is the moment you got anyone my dear students please comment you will get a value of how much if you solve

this you will get a value of 158.2mm so here you can write this as 158.2mm and

let me tell you what should be the key observation when you are writing the gate exam is units are also very important my dear students even though you they have done

up to here okay and you have given the answer this that will be wrong if they ask you the answer in kilon meter so always be

caution or precautionary measures is you should have an idea on units okay so please write down this students if you have any queries you can ask

me okay I hope you have written can you please comment in the comment box sir okay now my dear students this is one of

the interesting question of mine sir and this says how gate exam works for you these people know actually what happened students most of the it was a previous

year gate questions for your in previous year gate question and for your information students most of the students they know the concept but they have done wrong there is a logic there

that is the reason I'll give you two minutes of time just try this problem my dear students and I'll start the problem first try to read the question get the

gist of the question and you can tell me the answer for so try to read the question over there a singly reinforced rectangular concrete

beam of WID 300 mm effective depth 400 MM M25 concrete Fe 500 gr for the beam to be under reforced what is the Maxum number of 16 mm diab

bars what is the maximum number of 16 mm diars please write down that students are you following students okay I've given you enough time

sir I've given you enough time now see students let me tell you here first first of all for a beam to be are you following

my dear students if you have any queries you can ask me first of all for a beam to be under reinforced what sir for a beam to

be under reinforced for a beam to be under reinforced

okay what you can do is XU is less than xum Max or as is less

than as limiting what sir XU is less than XU Max or as is less

than as limiting these are the conditions agree my dear students yes or no so to find out whether the section is

under rainforce first try to ex first try to find out the limiting area of Steel okay to find the limiting area of Steel

we assume the section to be balanced what sir we assume the section to be

balanced so Here My Dear students 36 fck bxu Max let me tell you my dear

students bxu Max is equal to 87 FY as limiting

okay now my dear students if I talk about here as limiting if I talk here as limiting is equal to can be written

as 36 fck B into XU Max divided

by 87 F1 so in a gate exam my dear students let me tell you what is the given data is very important FY is the

M25 D is 400 MM and Fe is 500 so XU Max is how much sir XU Max for 500 grade of Steel what

is the value can anyone tell me XU max value for f500 it is 46d yes or no sir so here it is what is

the effective depth sir 46 into 400 so 46 into 4 it is

184 so it is equal to 184 mm XU Max is how much sir 184 mm so

here what is 36 into fck is 25 and what is the width of the section sir the width of the section is how much 300 mm

width of the section is 300 mm xum Max is how much sir 184 upon

87 FY is 400 okay now tell me sir what is this value now tell me anyone what will be

this value sir if you solve this value you will get a value of

42.6 mm squ how much you will get my dear students you will get a value of 11 14206 mm

squ so here what is's trying to ask sir here is trying to ask what is the number of maximum number of bars for a beam to

be under reforced yes or no my dear students so n into < by 4 into 16 square the D of bar is how much

sir 16 square is equal to what sir 11 14206 mm squ 11

14206 mm squ so my dear students what will be the number of bars if it is

equal divided by < by 4 into 16 squ the number of bars will be 5.6 now anyone who are observing this

answer what will be the answer sir so see students most of my previous students have written this answer as six

sir let me tell you after doing all the stuff hard work your answer is wrong why because you are losing the basic

concept that limiting area of Steel is more or your area of Steel provided is more than

limiting are of Steel then the section will become over reinforced so for a section to be under

reinforced the number of bars should be less than 5.68 so in this why this is a beautiful question let me tell you the answer can

be one bar two bar three bar or four bar or five bar but in that he has asked what is the maximum number of bars

so you can say that the answer is the maximum number of bars is how much five so this is the one beautiful question I would like to tell you if you write the

answer six then your answer is gone so the maximum number of bars which are provided of 16 mm to be

under reinforced is five if you write it is six then it is absolutely wrong the reason is it is losing its basic nature

which should be under reinforced if you provide six it will become over reinforced so that is the reason my dear students whenever you are attemp the

gate exam reading the question and understanding the pattern and also units given data is very very important so even though if you Le lose 20 to 30

seconds of your valuable time still read the question carefully write the units properly read the question write the given data then apply the formula then

you are 100% into the exam now my dear students you can solve this question here this is also another beautiful question but very pretty easy if you know the concept straightforward

question we have told you also for okay my dear students I have given you enough time AMA here see students we

have done all the given data so here a rainforce concrete beam of with width of 250 mm effective depth of how much sir

400 mm is reinforced with Fe 415 Steel as per the provisions of is 456 the minimum and the maximum amount of tension

reinforcement now my dear students let me tell you this question is very easy the minimum amount of tension reinforcement the minimum amount of

tension reinforcement agree my dear students the minimum amount of tension reinforcement is given by the

formula what sir the minimum amount of tension reinforcement is given by the formula ASD by BD is equal

to 0.85 upon FY yes or no 0 this is minimum tension

reinforcement into 100 but see students what they have given here sir see what is the grade of Steel 250 and 4 00 and Fe 415 what is

the grade of Steel they have given sir Fe 415 yes or no so here what should be the as so if it is percentage it will be 100

here also okay so 100 100 cancel we can say ASD by BD is equal to 85 by FY into

BD okay now my dear students if I talk here what is the grade of Steel 41 are you following my dear students the grade of Steel is 415 and what is the width of

the section sir width of the section is 250 and depth depth is 400 and most of the students might ask me sir sir this question they have given in the problem

they have told sir how you have taken 400 MM why you have not detected the cover this kind of questions you'll be asking so in the question they will

mention clearly that ignore the cover or they can say say that use effective depth as overall depth or use overall depth as effective depth this kind of statement they will give you 100% so

when you solve this you will get a value of 25 mm squ what sir how much you will get a value you'll get a value of 205 mm

squ this is the minimum tension reinforcement similarly my dear students if you talk about the maximum tension reinforcement what is the maximum tension

reinforcement I told you my dear students the maximum tension reinforcement is nothing but the 4 percentage of gross area what sir 4% of

gross area sir here there is no cover means we are assuming overall depth as effective depth and effective depth as overall depth so here it will be equal to

0.04 B into D agree now my dear students when I talk here 0.04 into width is how much sir 250 and

overall depth is how much sir it is 400 so this will be equal to Sir 250 into 25 into 4 100 25 into 4 this will if you

see 4,000 mm Square I think you will get because 2 into 4 100 100 into 4 0.04 it is how much sir 4 4 into 1,000 it

will be 4,000 mm squ so please write down this students everyone I hope you are clear sir I hope you are clear have you written sir uh next this is another important

question you can observe Here My Dear students the question is simple my dear students I'll give you a 2 minutes of time as I told you my dear students students here they have given the

frequency distribution of compressive strength of 20 concrete spacement and what they have given they have told that mu is the mean strength and sigma is the

standard deviation how many cubes are having a strength Which is less than muus 3 Sigma so my dear students I'll give you the hint also here you should

find the average of the cubes that is Mu after that you have to find out the standard deviation and calculate the value of muus 3 Sigma so please solve

this problem my dear students I'll give you 2 minutes of time I have told you what is the given dat also okay please solve the question my dear

students now see students what is Mu sir here please understand C here students mu is the what is the mean strength sir please see students most of

the people also do this mistake they take just average here but here you should understand there is a frequency

of spens so if you take 23+ 28 + 22.5 21 31 + 29 by 5 this is the common mistake they do but here this strength is having different spacement this strength is

having dis different speciment so overall there are 20 cubes so when you take the mean what you have to do how

many cubes are there of 23 4 so 4 into 23 plus how many cubes of 28 sir 2 so plus 28 into

2 plus how how many cubes of 22.5 5 cubes plus 22.5 into

5 plus what is the value sir 31 cubes are of five so you can write 31 into 5 plus how many cubes of of 29 strength

it is four so 29 into 4 divided by total number of Cubes what is the total number of Cubes my dear students can you please reply in the chat box so here the total

number of Cubs are 20 so my dear students when you calculate this see if you see this you have 4 into 23 92 56 5

into 22.5 112.5 31 into 5 155 and 29 into 4 is how much sir it is around 116 so if you do the calculation I think you

will get a value of 26 575 MPA or you can say Newton per mm Square so this this is what we got the

or 26. 575 or 26.75 sir okay just check

or 26. 575 or 26.75 sir okay just check it okay I hope you got the value of the average now my dear students you should

know what is standard deviation here standard deviation is given as what my dear students here what do you mean by standard deviation standard deviation is

given by the formula Sigma what sir what is the formula we have standard deviation is given by the formula Sigma

that is equal to Sigma I isal to 1 to n upon fi minus F average or you can say

mean whole Square upon n minus one s here also n if it is less than 30 samples we take n minus one so Here My

Dear students so if I take here so what is the value we got sir first one is 23 so you can say if I take the square root here

okay please 4 into 23 minus 26575 whole square plus how many cubes sir 5 28 of 2

cubes so 2 into 28 Minus 26.5 75 whole squ sir Here My Dear students as it is whole square

if it is average minus individual or individual minus average no issue because negative whole Square will be positive Square any positive

plus how many cubes are 22.5 cubes are of five 5 cubes of 22.5 -

26575 whole square + 5 cubes of 31 31 - 26.5 75 plus what is the last one we have 29

cubes strength how much sir 4 + 4 into 29 minus 26575 whole

Square upon what is the value sir what is the value here upon n minus one what is the value

of n n is the number of Cubes is 20 20 - 1 if you do all these calculations you will get a value of how much sir standard deviation you'll get a value of

3.69 7 what is the standard deviation you will get 3.69 7 now my dear students you should understand muus 3 Sigma what

is the value okay sir what is muus 3 Sigma if you calculate you'll get around what is the value sir you'll get anyone tell me 15.

485 so 26 575 minus 3 into 3.

697 if you solve this you because this is Mu this is what sir Sigma are you following my dear students that is Mu this is Sigma if you do this you'll get a value

of 15 485 MPA now they didn't ask you what is the strength or something what is the value of muus 3 Sigma let me tell you my dear

students they didn't ask you what is muus 3 Sigma what they have asked is they've asked what is the number of Cubes which are having strength less

than point and muus 3 Sigma so from this my dear students if I talk here sir is there any cubes which are having

strength less than 15 15 or 16 there are no cubes so the answer is zero as there are no cubes here the number of Cubes

which are less than muus 3 Sigma will be equal to how much sir zero I hope you are clear my dear students so I hope you are clear now my

dear students one second uh this is one of the easiest question but you should know my dear students try to solve this question I'll give you the

timer sir 2 minutes sir please utilize the time and uh get your all Concepts clear and if you have any queries you always feel free to ask in the chat box

my dear students okay for sir if you have any queries please ask me here for M25 concrete with a creep coefficient

of with the creep coefficient is how much sir 1.5 the long-term static modulus of elocity if you didn't observe creep

coefficient please write down creep coefficient as 1.5 okay my dear students I have given you enough time now see

students here first of all let me tell you let me tell you Here My Dear students whenever they ask you what is short temp modulus of velocity what sir

if they ask you what is short temp modulus of velocity sir in previous code book it is 5,700 root fck it is revised am short shortterm modulus

of elasticity shortterm modulus of elasticity is revised as what sir es s is equal to 5,000 root fck what it is

revised sir it is revised as 5,000 root FC you should remember this formula my dear students so if I substitute here 5,000 what is the grade of concrete here

sir grade of concrete given as 25 so the shortterm modulus of velocity on calculation my dear students 25 is 5 so

25,000 MPA or you can say Newton per mm Square MP or Newton per mm square is same a pascal is Newton per met Square okay now my dear students now you should

understand what is long-term modulus of velocity here if I talk about the long-term modulus of velocity you can write here shortterm modulus of velocity

you can write it as shortterm of velocity upon 1 + Theta what sir shortterm longterm mod sir here what is Theta it is nothing but creep

coefficient what sir Theta is nothing but the creep coefficient or if you want to know what is creep coefficient the definition means they can ask you

sometimes creep coefficient is given by the formula ultimate creep upon elastic creep what is the it is the ratio of ultimate creep upon

ultimate creep upon elastic creep what sir creep coefficient is nothing but the ratio of ultimate creep upon elastic creep now my

dear students here shortterm modulus of velocity is given as how much sir shortterm modulus of velocity is given as 25,000 upon creep coefficient they have

given directly as 1.5 so 255,000 divided by 2 .5 you'll

get a value of 10,000 MPA what is the Newton per mm Square sir you can say the shortterm modulus of velocity is 10,000 MPA my

dear students if you are having any queries you are always feel free to ask in the chat box so I hope you are clear please write down this students

okay I hope you have written this okay I hope you have written this student now this is a beautiful question sir I'll give you 2 minutes of time so

my dear students this is one of the good question also means you have to apply your mathematical skills here so if you know the mathematics there is nothing in here and the concept because something

you should know what is probability and all and also you should know how to solve the problem related to RCC so please write read this question students

the question is according to the concept of limitate design as per is 456 what is the probability of failure of structure what is the probability of failure of

structure I hope you are following the question students please write down the question for okay students I have given you enough time

AMA now see students carefully when I talk about the probability of failure of first of all how the stru can fail in LSM first you should

see there can be different cases sir okay if the strength is more sir there are two factors I'll tell you two

factors sir one is strength and another one is what sir load sir when they tell you here let me write here one is strength and other one

is load sir what is characteristic strength it is the strength at which 95% of the test results are passed what is characteristic load it is the load at

which 95% of the test results are expected to pass so now my dear students what is the failure means first case

strength fail means 5% so 95% pass means strength fail load

pass are you getting my dear students next second case load failure and next one is strength

pass and the third condition here is there can be load failure and also strength

failure now let me tell you when I talk about strength failure or load failure both are mutually exclusive events or independent events they are not

dependent on each other both are independent events are you following my dear students so here the probability of strength failing is almost sir if you

talk about the probability of failure of a structure if I talk about the probability of failure of a structure if I talk about the

probability of failure of a structure there are one is strength can fail load can pass load can fail strength can pass I told you again and again my dear

student what is characteristic strength it is the strength at which 95% of the test results are expected to pass what is characteristic load it is the load at

which 95% of the test results are passed so strength failure means

0.05 and load pass means 95% 0.95 plus now load failure so strength pass strength is

0.95 and load failure is 0.05 plus there can be three events which can be happening and both are failing so

0.05 and 0.05 so if you add these three my dear students the probability of the failure

of the structure will be equal to 0.975 okay sir what is the probability of failure of the structure by adding all these three you'll get

0.975 or you can write a value of 9.75 percentile my dear students now my dear students if you want to look into our test series plus you can just fill

the form which is given in the below okay sir if you have any doubt or if you have any queries or if you want to get in touch with imsg Academy related to the problem solving or test

series Plus or regarding the offline at Bangalore we are also offering the offline gate admissions at Vijay Also if anyone is really interested the Google Document is given in the link and you

can just click on the link and you can inquire yourself with our education adviser they'll get back to you okay so please write down this students hi hi hi kistan

so try if you have any queries you can ask me sir so here what is the final uh percentage it is 9.75 percentile I hope you have written this

students sir here I have written all the cases one is 10th failure load pass second one is load fail strength pass the third case is both can

fail so next write down this sum this is also one other important case you can write sir you can solve this question okay again I'll give you some 2 minutes of time quickly solve this question

students it's a very easy question if you know so please try to solve the question for if you have any queries you can ask

students for okay see students I have given you enough time MMA now please understand here what is the question here is they are asking see if the characteristic

strength of concrete F CK is defined as the strength at which not more than 50% of the tests are expected to fail then what is the in

terms of mean strength and standard deviation would be what sir the expression for fck in terms of mean strength yeah now see

students if you talk about characteristic strength let me tell you what is characteristic strength here if I talk

about what is characteristic strength is it is the strength at which it is the strength at

which it is the strength at which 95% of the it is the strength which what sir

95% of 95% of test results are it is the strength at which 95% of

the tests are expected to pass so my dear students if you see by

naming it follows 95% probability curve 95% probability curve so if you see

here okay if you see the 95% probability curve here this is called the 5% here this is the 5% where we call it as F

CK okay sir and here this is called the target mean strength and this is the standard deviation okay

sir now see students from the graph we can write that Target mean strength is what sir F CK plus K is a constant

deviation s is the standard deviation here what is s you can say s is nothing but the standard deviation okay my dear students now K is

a constant you can write here FM is equal to F C k+ 1.65 s but this is the actual definition but in the question he's

telling that characteristic strength itself is 50% here it is not 95% so it is changed to 50% in the given

question okay so when it is 50% are you following my dear students if it is 50%

sir okay initially at fck you it is at what percentile 5 percentile now this will be moved to same are you getting me

students here it coincides with the target mean strength so here the standard deviation will be zero so in

this case Target mean strength will be equal to F CK so by definition sir here they have given the definition in other way you can say the target mean strength

is equal to what sir F CK so please understand here the formula will be equal to characteristic strength will be equal to FM Target mean Str a Target mean strength will be equal to

characteristic strength okay so again this is one more good question sir try to solve this question okay pleas see first of all read the question carefully students

once you read the question you'll get an idea of the question okay please solve that question students if you have any queries you can ask me students

try to read the question carefully what is the given data if you have any questions you can ask me my dear student e

okay I've given you enough time students so here the question here is a rainforce concrete slab with an effective depth of 80 mm is simply supported at opposite

ends on 230 mm thickness masary wall the center to Center distance between the walls is 3.3 m as per is 456 what is the effective

span so Here My Dear students when I talk here they have given they have given you Center to Center distance between

the beams as amas Sir between beams is 3.3

met they have given this as the data now how do you calculate effective span let me tell you my dear students how do you calculate how do you calculate effective

span let me tell you okay it will effective span will be smaller of

both what is smaller of both means here I'll tell you sir the first case is clear span plus d clear span plus effective

depth this is from the qu sir and the second one is Center to Center distance between supports between supports you can write

so my dear students out of these two what sir out of these two which will be the smaller will be the effective

span now see students if they have given you here they have given what sir let me tell you okay they have given a simply supported beam right

students okay this is a simply supported beam what they have done here is they have given you the center

to first they have given what sir they have given this Center to Center distance as how much

sir 3.3 M right students and now what will be this length this is thickness of the wall is 230

mm okay now my dear students we should find find out what is the clear span what should be the clear

span now from the figure it is clear clear span plus thickness of the wall so you can write here clear span

plus thickness of wall is equal to Center to Center distance distance now my dear students if I talk

here clear span clear span plus 230 mm means 23 m center to Center is equal to 3.3

M okay so here what will be the clear span sir clear span is 3.07

M now my dear students in the problem they have given effective depth as in the problem this is given data

effective depth is given as how much sir effective depth is given as 80 mm how much sir effective depth is given as how

much 80 mm so you can write this as 0.80 M so if I asked you here now clear span plus

d okay so this is 3.07 + 0.08 this value will be equal to 3.15

M okay now see students here the center to Center distance is how much sir 3.3 and if you talk about the clear span plus d it is 3.15 so the smaller value

will be with the answer so the answer here is 315 M what is the answer sir the answer here is 3.15 M any doubts in

this students any doubts in this please write down this sir please write down this students I hope you have written this

students so simple thing here what is the key takeway from this problem is the effective span is nothing but the smaller of the center to Center distance between the supports or clear span plus

d for simply supported if it is for C beam this formula is clear span plus d by2 okay so please write down that students okay I hope you are

clear now please read this question actually you have done this you can solve this question students I'll give you 2 minutes of time so try to do that question okay if you have any queries

you can ask ask me for sorry for okay sir I have given you enough time so my dear students when I see this question here what is the question here

is a singly reinforced concrete beam of a balanced section is made up of M20 concrete and f415 grade the magnitudes of the compressive strain in concrete maximum compressive strain and tensel

strain in the ultimate State under fluger is what is the grade of Steel sir f415 so my dear students when they ask you as I told you in one of the

Assumption I told you the maximum compressive strain is straightforward this is from the code itself the maximum compressive strain in

concrete the maximum compressive strain in concrete is how much this is given directly from the code which is equal to how much sir which is equal to

0.35 what is the value sir which is equal to 0.

35 now similarly my dear students if they ask you what will be the maximum denile straining in

steel or maximum strain in Ste so here what is the formula it depends purely on grade of Steel it is 87 es

plus 0 02 here in this problem my dear students what is the grade of the steel they have given the grade of the steel is given as

415 are you following my dear students so here it will be taken as 87 into

415 upon X modulus of the steel is 2.1 into 10^ 5 plus 0.2 are you following my dear students

so on solving this is you will get a maximum strain as how much sir 0.

0 38 what is this answer sir 0.38 so here the option which is having 0.35 and the answer which is

having 0.38 is the option sorry option A is the right answer agree my dear students I hope you are clear so whenever you are

solving the maximum strain the key takea is the maximum strain compressive strain in concrete is 0.35 and the maximum tensile strain

depends on the grade of the steel so please write down that I hope you have written this students I hope you have written this okay

now I think it's not visible properly next question you can solve this question sir I'll give you 2 minutes of time please solve this question students

if you have any queries you can ask me students first read the question here carefully for for okay okay students I have given you

enough time AMA so here please read the question a rainforce concrete Beam with a rectangular cross-section of 300 mm effective depth 580

mm is made up of m30 concrete what sir it is made up of m30 concrete it has 1% longitudinal tension reinforcement of fe4 and5 the designed Shear strength for

the beam is how much sir 0.66 the beam has to resist a factored Shear force of 440 Kon the spacing of 10

mm D vertical stups of fe4 and here see students they have given you two-legged what they have given sir they have given you two legged that is very important my dear

students so whenever these kind of questions are asked so first let me tell you we have to find out the nominal shear stress so what is nominal shear

stress V upon BD so they have given Shear force is 440 Kon so 440 Kon means if you convert this into Newton

so it should be equal to 440 into 10^ 3 so it should be 440 into 10^ 3 and what is the width sir width of the section is

300 mm and effective depth is 580 mm so 300 into 580 so if you solve this what will the nominal sheer stress sir you'll get a

value of 2.52 you'll get a value of 2.52 Newton per mm square or you can say MPA but

what is the value of Toc they have given so Toc is given as 0.66 and remember my dear students now toi Max also we have to calculate it

will be equal to some 0.62 into fck is how much sir m30 concrete okay it will be somewhere around if you see it will be 5.5

somewhere around 3.3 I'm not writing the exact value it is 3.3 so you your your

TV is less than Toc Max so no need of redesign no need of what sir no need of

redesign but let me tell you no need of redesign but here what you have observed T is greater than toi my dear students

what sir T is greater than toi so when TV is greater than Toc you should understand here that sheer reinforcement is

mandatory when T is greater than T C what I have told you sir sheer reinforcement is mandatory now my dear students so if you

want to find out here so here if I talk about the design sheare Force the design sheare force is equal to TV minus

TC into B into D so TV is how much sir you have calculated as 2 2. 528 I hope you are following students and what is

the value of toi here it is 0.66 into B into D B is how much sir 300 into effective depth is 480 or 580 sir

just check the value it is 580 th 300 into 580 so if you solve this 3 into 58 150 174 174 into 1.91 so if you solve this

you will get a value of 325.00 3 into 10^ 3 Newton you'll get because this is design Shear Force there is another

formula also design Shear force can be written as 87 FY ASV into D upon

SV okay sir what is the grade of Steel here it is 415 so 87 415 into ASV is how

much sir 2 into < by 4 into two leged so that is the reason I have written two sir why I multiplied with two here because it is two-legged 2 into < by4

into DA square what is the da of the stup it is 10 square into effective depth is how much sir 580 divided by SV is equal to how

much sir 325.00 3 into 10^ 3 Newton so if you solve Sol this you will get SV Valu is much sir if you see if you solve this

you'll get a vertical spacing value as 101.2 mm so this will be your final answer they have asked you what is the spacing so please write down this

students so please write down that students if you have any queries you can ask me sir have you return students this is another question try to

solve this question first of all whenever a question is given try to read that question carefully try to read the question and if you have any queries you can ask me

students for if you have any queries you can ask me in the chat box sir okay students I've given you enough time so what is the question here is the

cross-section of a rainforce concrete beam having an effective depth of 500 mm the Gres of the concrete are M35 and Fe

550 mm the area of the steel factor of safety is 1.15 for steel as they have told and the yield strain of F50 is they have given sir also as

0.44 now the limiting depth of the neutral axis is so they are asking what is the value of limiting depth that means what they are asking sir they are

asking the value of XU Max they are asking the value of H they are asking the value of XU Max okay now see

stent suppose here let me show you students if I considered here A T beam okay this is the T

beam and if I take here this is the steel okay I hope you are following students now if I considered here this

is the strain diagram right so what is the value here here it is the value at compression is 0.35 and here it

is 87 FY by es + 0.02 actually it should be but they have given this value is how much sir

0.44 they have given this value right now from similar triangle concept if I consider this as XU Max this is known as XU Max

and you know this is how much sir effective depth D yes or no my dear students are you following sir and what will be this value sir this value will

be equal to D minus XU Max what will be this value sir D minus XU Max so

here okay here if I write here D minus XU Max D - XU Max upon XU

Max what sir if I write here D minus XU Max is how much sir it is nothing but

0.

44 upon x max is how much it is equal to 0.00 35 yes or

no now see students d by XU Max Min - 1 can be written as what sir 0.44

upon 35 okay now see students d by XU

Max can be written as after solving 35 Plus it will be 79 by 35 now see students if they ask you what

is the depth of neutral axis is that is equal to 35 by 79 into D what is the effective depth sir they have given

effective depth as 500 mm so it is equal to 35 by 79 into 500

mm okay it will be roughly around 6.25 into 35 180 180 and 210 something around 221 you'll get sir if you solve this

you'll get a value of around 221 mm okay this is the xumo ax or you can say limiting depth of neutral axis okay please write down this

students please write down the students you'll get a value roughly mean exactly you'll get a value of 225 okay please write down this

students I hope you are clear sir okay next this is a very good question sir try to solve this question it's a question due to loss of pre-stress and

I'm thinking this year no losses of priess can be expected question losses of priess we can expect a question okay this year I'm expecting a question

from loss of Priestess okay for please write down that question students if you have any queries you can ask me I have I hope you have read the question

so my dear students a concrete beam of span 15 m 150 mm wide 350 mm deep is pressed with a parabolic curve of coefficient of fraction 35 o

constant 0.05 if the cable is tensioned from one end what is the percentage of loss right now see students when I talk about this question first of all you

should understand what is the percentage of loss of press due to friction first you should understand this question this concept

before solving that question what is the percentage of loss of pre-stress due to friction sir see when I talk about you

the percentage of loss of priess due to friction okay you have this sum Delta

P you have this Delta P loss of priess du to is given as P into Mu Alpha

+ K into xar okay now see students it will be the pre-stressing this is loss of pre-stress right or you can say this is initial

stress this is what sir initial stress and C sir this point you should please remember my dear students it will be

equal to P if it is tensioned from one end what sir it will be equal to P not if it is tensioned from one end if it is tensioned from both ends it will be

equal to what sir P by 2 if it is tension from both ends it will be equal to what my dear students it will be equal to P by 2 let

me tell you so here what is Mu if they ask you are you following my dear students mu is nothing but the

coefficient of friction what is Mu sir mu is nothing but the coefficient of friction mu is nothing but what my dear students mu is nothing but the

coefficient of friction agree or not and what is Alpha Alpha is nothing but the cumulative angle in

radians what sir cumulative angle in radians I hope you are following students Alpha is nothing but cumulative angle in what cumulative angle in

radians suppose my dear students if I take here as a span okay if it is a parabolic arch if I take this as rise as

H and if I take this as length okay okay what is cumulative angle here is this is Theta 1 this is Theta 2 okay you will

get rise is equal to actually General equation you know right students Y is equal to 4 H by l

s x into l - x if you solve this usually remember this students Alpha will be taken as 8 H by

l h is the rice what is h sir H is nothing but the rise L is the spam so we are done with mu means what sir coefficient of fraction

Alpha is the cumulative angle in radians which is 8 H by l h is the rise and L is the length of the spam and here we have K or here only I'll write sir K is

called wobbling constant what sir K is called what oing constant now what is oing effect or anything if you see sir my

dear students if I consider this as a duct if you introduce the tendon here the tendon will not be straight Instead This will be somewhere like this that is called oing effect or curvature effect

or you can say length effect Here xar is known as what sir xar is known as the length of span what is xar my dear students xar is nothing but the length

of the span so here you have known what is p not initial stress if it is tension from one and it is equal to P if it is tension from both ends then it is equal

to both ends P by 2 mu is the coefficient of friction Alpha is the cumulative angle in radians you have to see the shape of the 10an if it is Parabola then it is 8 H Bell it can be

triangular also and K is the wobbling constant and xar is the length of the span so my dear students in this question it is tensioned from one and only and they are asking what is the

percentage of what is the percentage loss okay now my dear students if you ask me what is the

percentage loss of priess what is the percentage of loss of Priestess due to friction what is the percentage of loss

of priess due to friction if they ask me what is the formula sir you can say here Delta P

by P Delta P by P into 100 is equal to you can write it as Mu Alpha plus K xar okay in this problem if you see mu is

given as how much sir it was given as 0.35 xar now see students let me tell you how to find out Alpha here this is

the one I would like to tell you here sir if you see here the rise is how much sir 70 + 50 are you following so

here H is equal to if you see my dear students Alpha is equal to 8 H by L right so H is what s rise so it is 70 +

50 mm so you can say 0.07 + 0.05 meter what is the length of the span sir length of the span is how much

is equal to 15 yes or no my dear students so here it value if you calculate the value it is equal to how

much sir 0.012 right 8 into 0 75 0.12 upon 56 so what is this value sir can anyone

tell me what is this value 0.96 right so you'll get a value of 0.0 64 you'll get the value of how much sir

0.064 I hope you are clear now my dear students mu is equal to how much sir

0 35 Alpha is how much sir Alpha is 0.064 K bar that is oing constant what is the oing constant given in the problem it is given

as 0.15 into what is xar Sir 15 so if you solve this students you'll get a value of into 100 should be there sir here we have to

multiply this because it is in percentage multiplied by 100 you will get a value of 0.449 if you do with 100 multiply with

100 you'll get a value of 4.49% so the percentage loss of priess is how much sir 4.49 percentile so please write down this students sir this

is a very important question Amma and remember the loss of pre-stress due to friction occurs only in post tension it is not observed in

pre-tensioned members sir what is pre-tension means if the tension is if the wires are tensioned before casting we say it is pre-tension if the wires are tension after casting then it is

called post tensioning okay so please write down this students if you have any queries you can ask me sir sir here the most challenging part

is Alpha only what is the alpha is Alpha is nothing but the cumulative angle in radians it is 8 H by L for a parabola okay how easily we can solve the

question if you know all the temps students if you don't know the temps this question also feels very difficult for you now this is a straightforward question and it's one of the previous

year gate question only students so please try to solve this question okay I'll give you 2 minutes of time for e e

hi students I think I have given you enough time I told you clearly students what is effective cover and what is nominal cover see Here My Dear students if they ask you effective

cover always remember it is from centroid of Steel it is from centroid of steel or

you can say center of the steel bar Center of steel bar to extreme fiber so from here if you can

exclude okay nominal cover here we should understand what is nominal cover let me tell you here what is nominal cover nominal cover

means this part okay here what I should tell you students here let me draw this diagram very clearly if I have the diagram here they have a steel bar here

right in this steel bar the center to Center distance is given as 15 okay now this here we have let me show you

here we have stir up also what sir here we have here we have what sir

stup okay this value is how much 15 now the steel rod di is how much 16

mm and this tup value is how much sir 12 now we have to calculate this distance only what is this distance that is called what our nominal

cover that is called nominal cover I hope you are following students this is the nominal cover which you have to find out so how to find out nominal cover sir

effect you can write here effective cover minus effective cover minus D by2 of main bar minus da of stup

okay so it is equal to 50 minus 60 by 2 minus D of stup is 12 so you can write here it is 30 mm so you

can write how much sir it is 30 mm so the option A is clear sir remember Simple Thing effective cover means it is the distance from the centroid of the

steel bar to the extreme fiber in nominal cover we exclude the stup DIA also because people will try to include that and they will do mistake so that

thing I would like to tell you okay please write down the students I hope you have return this students next okay this is another important

question sir you can go through this question question related to column you can do this question also I'll give you 2 minutes of time

students try to read the question okay so it's a column question try to read that question carefully if you have any queries you can ask

me for I think I I hope you have written this question sir now my dear student friends let me see here sir the question here is

very simple an RCC short column with a rectangular cross-section 250 into 300 is reinforced with four numbers of 16 mm da the grades of Steel and concrete are

415 and M20 neglect the eccentricity effect this is very very important student when they give you neglect the asent now see students if you see the

ultimate load now see students if they give you the ultimate load how to solve the ultimate load let me tell you my dear

students if you see here ultimate load is given by the formula 0.45 sorry 0.4 0.4

fck AC plus 0.4.7 FY AC okay sir this is the formula for

ultimate load cons considering eccentricity what sir considering eccentricity effect but in this question the ultimate

load is given by the formula 0.45

fck into area of concrete plus 7 FY area area of steeling compression okay this is the formula when you consider when you

neglect the eccentricity this is the formula for when you neglect the one second students this is the formula when you

neglect e centricity okay now see here my dear students when I talk about this gross area minus area of Steel in compression

will be your area of concrete okay here what is the section details sir it is 250 into 300 and four bars of so gross area is how much sir

250 into 300 minus four bars of 16 mm Square so 4 into < by 4 16 squ will be your area of

concrete now see students if I start here pu is equal to what sir 45 f c AC area of grade of Steel grade of concrete

is 20 right AC area of concrete is how much sir here you can write 45 into 20 area of fck 45 FC AC AC is how much sir

250 into 300 - 4 bar into < by4 into 16 s this is

the things due to concrete I hope you are following plus 0.75 into FY as 415

into 4 bars of 16 mm² if you solve the stents everything

you'll get a value of 9 98.1 into 10^ 3 Newtons if you solve this you'll get 98.1 kilon

is the final answer so my dear students Whenever there is neglect eccentricity the point4 will become 45 and 67 will become 75 please keep this in

mind okay so please write down this students if you have any queries you can ask me students if you have any queries related to this you can ask

me students if you have any query regarding this you can ask me sir okay this is a simple question at least try to solve this question I would be happy if you solve this question okay

this is a simple question try to solve this is according to the specifications according to the codal specifications sir please try to solve that question okay for

sir try try to read that question as per is 456 the minimum percentage of tension reinforcement required in reinforc concrete beam of rectangular crosssection using fe500 grade of Steel

that is the question they have asked sir okay whenever these kind of questions are asked you should understand my dear students what is the minimum tension

reinforcement okay so here when they ask you sir according to the is 456 code

what sir according to the is456 code ASD by BD is equal to 0.85

by FY if they ask you percentage means they are asking ASD by

BD into 100 this is the percentage of Ste so PT is equal to 8 85 by FY into 100 and they are asking for which grade

of Steel sir they are asking for the grade of 500 grade of Steel so here you can write here if I substitute here 85

upon 500 that is the grade of Steel into 100 I hope you are following students what is the grade of Steel there sir 500 so if you solve this you will get a

value of 0.17 percentile any doubts in this sir so it is a straightforward question so I told you already this is the question where you have to remember and if they

ask you what is Max on tension reinforcement it is 4% of gross area any doubts in this students if you have any queries you can

ask me in the chat box sir okay try to solve this question sir it's a good question and try to solve if you have any queries you can ask me here it is a pretention members sir when you talk

about the loss of of pre-stressed in concrete beams we have loss due to elastic shortening loss due to the shrinkage loss creep loss loss due to

relaxation but the two losses the loss due to Anchor sleep and loss due to friction these two losses are specific to the specific to the post tension

members and when you are solving the stresses in the loss due to elastic shortening the most important observation you have to do is you have to find out the stress at the level of

Steel not at the extreme fiber because we are habituated to find at the extreme fiber but here you'll find the stress at the level of Steel so please keep that in mind students okay I'll give you 2

minutes of time and try to solve that question okay sir C and read the question at least if you can if you cannot solve the problem okay

for for so try to read the question properly a pretension rectangular beam of 150 mm wide and 300 mm deep is priess with three straight TS having cross-sectional

area of 50 mm Square how much sir 50 mm square and the initial pre-stress is 1200 Newton per mm Square the tendons are located at 100 mm

from the sofit of the beam the modular ratio is six calculate the loss of pre-stress force not pre-stress sir calculate the loss of priess force due

to elastic deformation this is the question they have asked you right sir so whenever these kind of questions are asked my dear students see here you

should understand here the loss of Priestess what sir the loss of

Priestess the loss of Priestess due to the loss of Priestess due to elastic

deformation what students the loss of Priestess due to elastic deformation the loss of pre-stress due to elastic

deformation is given by the formula what sir it is given by the formula M into FC what sir M into FC what is M

here m is the modular ratio what is M students m is the modular ratio FC is the

stress I I hope you are following students FC is the stress at the level of Steel so when the comes the picture S at

the level of Steel sir C how do you calculate FC is FC is equal to load upon area plus p² by

I okay now see student they have given 1200 Newton per mm Square so that is the initial stress with an area of tendon having a cross-section area of how much

sir 50 mm Square so here how do we calculate first we have to calculate the load right student and what is the section sir it is 150 into 300 mm so 1

1200 into how many tendons sir it has press with three straight tendons of having a cross-sectional area of 50 mm square right so here if you see what you

have to do see students here what is cross-section area area is how much s 150 into 300 mm squ okay so you can

write it as 45 into 10^ 3 because this is the section what they are getting am I correct or wrong now in what how do you find out load sir how do

you find out load load is nothing but what sir stress into area okay so what is this is the area of section not

tendance sir this is area of section so 1200 this is how sir 1200 this is Newton per mm for each tendon it is 50 mm

Square for each tendon it is how much sir 50 mm square into area is how much how many tendons sir three tendons so

you can say 60 into 180 into 10^ 3 so this is the load now how do you find out acentricity sir 100 mm from bottom right

the tendance are located now how to find out acentricity sir if I take this s section this is how much M 300 mm I think 300 mm means if you consider this

as half this is 150 so 100 mm from here it is 100 so this will value will be equal to how much sir 50 yes sorry this is bottom is

how much sir from here it is 50 100 so centricity e will be equal to how much so how to find out acentricity

overall depth minus 2 minus 100 from the bottom so 300 by 2 - 100 this is equal to how much sir 50 mm okay I hope you

are following so here if you solve here 180 into 10^ 3 upon 45 into 10^ 3 because we know

this values plus 180 into 10^ 3 into 50 s upon what is I sir I is nothing but BD

CU by 12 B is how much 150 into 300 squ divided by

6 okay so here if you see 45 into 10^ 3 will come 50 50 means if you see all these things okay so here 150 into 350

so if you solve this you will get a value of around 5.33 MP how much you got sir

5.33 MP I hope you are clear okay sir I hope you are clear 5.33

BD sorry BD CU by 12 Sor here not BD s by 6 here it is BD 300 Cub by 2 okay

because 150 into 300 this is 600 if you s all this you'll get 5.33 MP I hope you are clear now see students what is the loss of priess

Sir what is the loss of Priestess I hope you are following students the loss of Priestess due

to elastic shortening the loss of press due to elastic shortening is how much sir how they have given this value how they have given this value can you tell me students if you have any queries you

can ask me sir here it is given by the formula M into FC so 6 into

5.33 so here it is a sir 32 1 by 3 means 2 so 32 MP but they asked what is the loss of pre-stressing food force not pre-stress sir most of the people will

do this wrong okay if you see now the loss of pre-stressing Force if they ask you what is the loss of pre-stressing

Force if they ask you what is the loss of pre-stressing force that is equal to stress into area area of the steel is three tendons of 50 mm squ so 150 into

4,800 Newton if they ask you in kilon the loss of pre-stressing force is 4.8 K what is the loss of pre-stress Sir 4.8

Kon now see students let me tell you here so one of the important things AMA this year I'm expecting this question also loss due to elastic shortening what

sir loss due to elastic shortening is given by the formula is given by the formula what sir it is given by the formula M into FC I hope you are following students m is the

modular ratio which is ang modulus of Steel upon Ang modulus of concrete what is FC sir FC is nothing but the stress at level of Steel what is FC FC is

nothing but the stress at the level of Steel similarly if they ask you okay if they ask you loss due to shrink Cas what sir if they ask you do loss due to

shrink case you can write this as Ang modulus du Ang modulus of Steel into string strain what this called sir shrinkage string similarly if they ask

you I hope you are following students if they ask you loss due to creep if they ask you loss due to creep if they ask

you loss due to creep sir it is given as 5 into M into FC or five into electric shortening you can write what is five sir five is nothing but the five is

nothing but what my dear students five is nothing but the ultimate creep coefficient f is nothing but the ultimate creep coefficient

okay now my dear students let me tell you the most important thing if you are preparing for gate exam test series is one of the important thing because as as you have already done your practice as

you have already prepared for the exam now it is the time to test yourself in a gate environment how to accustom to the virtual calculator how to get tuned to the time management so we at IMs Gate

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the marks will be from the grade previous year questions concepts are in so we are also providing the gate question booklet in the that in the test series plus program so students who are

really excited to write the G exam as if in a g environment or if you want to test yourself or how you can make your weakness into strength you can gu try with our test series plus and remember

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you have any query questions we are providing the offline gate coaching at Bangalore near malleswaram and also at jainagar we are also providing the offline gate coaching at uh vayada and remember my dear students we are

providing the online gate coachings and you can get all the notifications when the batch is going to start or if you are really preparing for the gate 205 exam my dear students it is the time to

test yourself so if you are looking for that you can join our test series plus program and get accustomed to the gate environment questions I hope this video on RCC will clear all your doubts

related to some of the critical Concepts I hope this video will help you thank you