SINGLY REINFORCED CONCRETE BEAM IN RECTANGULAR SECTION PART 1 OF 2

[@cristelannsison1204]

Good day, Engineer. Is there a required minimum beam sizes that we need to follow when we start designing? Thank you!

[@nioroskyengineeringonline8968]

yes based on seismic requirement with respect to the ductility ratio. out of that makakacompute ka ng minimum size ng beam width. that will be discussed in my future video lecture uploads

[@rayleigh920]

27:37 - 29:00 Φ = 0.65+0.25(εₜ-εₜᵧ)/(0.005-εₜᵧ) Φ = 0.65+0.25(0.0029609-0.002)/(0.005-0.002) Φ = 0.7301 Ayan po pala ang katumbas ng na-derived nyong algebraic expression to determine reduction factor (based po dun sa original form ng formula na inassign ng ncsp). Bali, sinet lang po pala yung value ng εₜᵧ=0.002?

[@rayleigh920]

Tanong po, bakit po kailangan i-set yung value ng εₜᵧ=0.002? Bakit hindi na lang po gamitin yung value ng given yielding stress, and by hooke's law, i-convert yon into yielding strain at sya na yung magiging value ng εₜᵧ: εₜᵧ=fᵧ/E =580/200000 =0.0029 Φ = 0.65+0.25(εₜ-εₜᵧ)/(0.005-εₜᵧ) Φ = 0.65+0.25(0.0029609-0.0029)/(0.005-0.0029) Φ = 0.6573 Please enlighten me sir.

[@nioroskyengineeringonline8968]

hi. Based on the perception of code and my derivation (according din sa derivation ni macgregor and other authors from ACI) are the same. here is the link of the derivation in my playlists: kzbin.info/www/bejne/m16mgJZ6d52MbMU. yung pinakita mong formula from the NSCP which is explained ind etail in the attached URL of my derivation and the derived formula i presented are both taken from the line diagram of strain witht the equivalent reduction value for compression and tension controlled system. My derivation (taken from my studies from Macgregor, an author of ACI codes that our local code is using and adopting) is similar to what is written on the code with different face :) and it is taken from the strain relation to constant of flexural reduction. My perception to the statement of our code suggest it may differ the value of Strain at extreme yielding specially if there will be new standards of the reinforcements.

[@nioroskyengineeringonline8968]

eto yung link ng screenshot from the derivation of maccgregor, author of ACI 318, which is the source of the cod ng NSCP 2015 :) : nationalueduph-my.sharepoint.com/:i:/g/personal/ngfuriscal_national-u_edu_ph/ERvjZKJyQW5CtwW2ZdLBFPcBTlvoOxV-731xm-fNz8dZ9A?e=G6qqsc .

[@nioroskyengineeringonline8968]

i Think i can have some updates also to my video lecture, which is also correct, to the way i present the reduction factor calculations where it is accepotable that the compression controlled system is accepted if Ety is equal or less than 0.002 where NSCP 2015 is also telling us that will validate my derivation true. However they mixed up the new code from ACI 318 - 19 where the the compression controlled syustem is accept as equal or less than Ety = fy/ES where it is very near to 0.002 where your presented form ula from nscp derived from my presentation also is the same source. Clearly our NSCP 2015 mixed up two possible assumptions when the beam flexure is under compression controlled. I will make a video lecture updating these codes when the new NSCP arrives :) cheers. for the time being since NSCP accepts the compression control happens at Ety

[@rayleigh920]

THANKS PO! Napaka informative po ng mga vids nyo. Looking forward po sa next vid nyo po na yan at will start na rin po mag binge-watch ng mga youtube uploads nyo haha. Thanks po ulit!

[@jasminekiakan5312]

Sir, pwede po ba i compute yung y bar ng ganito 2(25)/5 ? Y bar from top of the main bar ng first layer rebars? Thank you:)

[@nioroskyengineeringonline8968]

Follow the rule of statics using varignons theorem

[@franzanferneefelipegeneros2292]

Sir yung RCD lecture sir is in NSCP 2015 po? Possible 2015 na daw gagamitin na code ni examiner according to some rumors po? hehe

[@nioroskyengineeringonline8968]

Nscp 2015 gamit ko sa mga lecture videos ko in rcd, steel, prestress, and foundation.

[@jejejadeds]

Di na kayo gumagamit sir ng rhomin, rhomax? More on strain relation nalang.

[@nioroskyengineeringonline8968]

Rho min and rho max are used to identify the constraint whethere compression bars are necessary. I have a discussion on doubly reinforced concrete beam principle in the RCD playlist. Also rho min are used if tension reinforcement are to be designed. Here all elements are present and identified as singly reinf since it was not mentioned to design for the steel reinf. And the problem offers pure inveatigation of capacity. So no need for ductility check since it was identified already as singly reibforced concrete beam and reinforcement was provided. Cheers :).

[@mf3746]

sir ung conc.cover ung main bars mag bibase? paanu ung strirrups sir nasa labas po ng main bars?

[@imolodi4351]

Sir mali po ata ung formula niu dun sa beta sub 1(B1)?

[@nioroskyengineeringonline8968]

hi. tama po ang calculations ng betasub1. nadiscuss ko sa past video lecture ko yung type error ng NSCP 2015 1st printing. you can check the 3rd printing or ACI318 code for validation. cheers :)

[@nioroskyengineeringonline8968]

check this out: drive.google.com/file/d/1TPianDlUM5AXNLKWAWGL2Fn8G3rSLGDk/view?usp=share_link regarding source code natin ng NSCP 2015 for betasub1