Would like to make a shout out in the auditorium- big thanks to the Prof. You are bringing good value to the space. Please keep it up. Just found out I passed my PE exam. Your content helped me out for the afternoon session. I will tell you what- I know I crushed the concrete beam shear problem that was on my test. Big ups!
Working as mostly a drafter atm, but one thing that an engineer brought up to replace rebar stirrups, is to use WWR mesh to accommodate. Seems like that would be a good way to go for some things since the diameter of the steel is much smaller, typically of higher grade, and one wouldn't have to place multiple stirrups during fabrication. Do you foresee any potential issues with that WWR/stirrup approach, or would that be a good path to reduce the amount of materials and maintain max spacing requirements? Just trying to get a sense of what you think and if there are any limitations to watch out for. Great videos btw. Really helps with figuring out what is important so I can get a PE eventually, or at least have enough knowledge to help make sure designs are safe as well as efficient.
Hi David, when Av is required per the ACI then a lot of the time Av min requirements will also be required. because of this you will be hard pressed to get WWR to meet those requirements. WWR is like welded wire fabric correct? that's what im picturing. and if that is the case WWF has very little steel area. great ideas tho. please let me know if im understanding you correctly.
@@Kestava_Engineering Yes, you were understanding correctly. Sorry for the late reply. Not sure why I didn't get notified, but yeah, I agree. As I work in the field I am finding that WWR can work if sized and spaced correctly, but mainly in places that are small, like a slab with holes in it that is in the realm of 10x10 ft horizontal dimensions and if those slabs are standard precast products used often (wwr takes more time to make than bar due to ordering and design processes). When things get bigger, it often seems that the flexibility of stirrups in rebar format would be better so adjustments can be made during cage assembly. Definitely a trial and error sort of thing. I work in a plant environment, which is nice in a way, as I get to see the impact of design decisions pretty quickly. As far as the math. WWR can replace bar. For example, if one needs #3 bar @ 4" oc, then one could probably use D-11 wire @ 4" oc assuming same grade of steel, since the area steel per bar/wire is nearly the same. Sometimes the wwr is faster to use, and therefore cheaper. I have used WWR a bit to work to improve shear capacity while also providing something like "scaffolds" for top mats to help with assembly... that definitely helped speed of production.
Great video again btw (refreshing as time is coming for testing!), more to my point with the wwr though, we could hypothetically use wwr to get a "bar" smaller than #3 as you were talking about shortly after timestamp 14:00 of this video. Situational use still, and won't always be the best choice, but I think wwr could be a good candidate to consider when we want a smaller "bar size".
First I want to thank you about this video , second what do you think the beat book to learn reinforcement concrete design according to aci i try nilson book but have a problem with example in this book not practical
you're correct - it is just Vs. however i like to compare with phi included so i can quickly compare by doubling the concrete capacity. adding phi to both sides of the equation should not change the comparison. but if you disagree you can / should use Vs for sure!
you only get to use the steel that is going through the shear plane. the top and bottom of the shear stirrups do not cross the shear plane. think about how a beam fails in shear and the look what shape the shear plane is. hopefully this helps! i can talk a little further in this
have you started designing with ACI 318-19???
I passed my Florida PE exam! Your channel helped me a lot, thank you!
LETS GOOOOO 🙌
Would like to make a shout out in the auditorium- big thanks to the Prof. You are bringing good value to the space. Please keep it up. Just found out I passed my PE exam. Your content helped me out for the afternoon session. I will tell you what- I know I crushed the concrete beam shear problem that was on my test. Big ups!
lets goooo. keep cookin!
For those wondering, Vs equation is in section 11.5.4.8 in ACI 318-14
Great video, I've been binge watching a bunch of your steel and concrete today in preparation for my PE Civil Structural exam in June.
lets goooo! love to hear it. more concrete videos coming out soon!
@@Kestava_Engineering any chance you could upload a basic prestressed concrete problem that uses PCI? There’s a PE question I could send you :)
The Vs in table 9.7.6.2.2 that is compared with 4Vc and 2Vc is the required Vs, i.e. Vs = (Vu - phiVc) / phi.
I love your channel. Thank you for the awesome Vedios ! Love your work :)
thank you! keep sharing and spreading the engineering love!
You are the best I really appreciate it thanks
Any time!
Thanks for sharing! 💯
i got you!
Working as mostly a drafter atm, but one thing that an engineer brought up to replace rebar stirrups, is to use WWR mesh to accommodate. Seems like that would be a good way to go for some things since the diameter of the steel is much smaller, typically of higher grade, and one wouldn't have to place multiple stirrups during fabrication.
Do you foresee any potential issues with that WWR/stirrup approach, or would that be a good path to reduce the amount of materials and maintain max spacing requirements? Just trying to get a sense of what you think and if there are any limitations to watch out for.
Great videos btw. Really helps with figuring out what is important so I can get a PE eventually, or at least have enough knowledge to help make sure designs are safe as well as efficient.
Hi David, when Av is required per the ACI then a lot of the time Av min requirements will also be required. because of this you will be hard pressed to get WWR to meet those requirements. WWR is like welded wire fabric correct? that's what im picturing. and if that is the case WWF has very little steel area. great ideas tho. please let me know if im understanding you correctly.
@@Kestava_Engineering Yes, you were understanding correctly. Sorry for the late reply. Not sure why I didn't get notified, but yeah, I agree.
As I work in the field I am finding that WWR can work if sized and spaced correctly, but mainly in places that are small, like a slab with holes in it that is in the realm of 10x10 ft horizontal dimensions and if those slabs are standard precast products used often (wwr takes more time to make than bar due to ordering and design processes). When things get bigger, it often seems that the flexibility of stirrups in rebar format would be better so adjustments can be made during cage assembly.
Definitely a trial and error sort of thing. I work in a plant environment, which is nice in a way, as I get to see the impact of design decisions pretty quickly.
As far as the math. WWR can replace bar. For example, if one needs #3 bar @ 4" oc, then one could probably use D-11 wire @ 4" oc assuming same grade of steel, since the area steel per bar/wire is nearly the same. Sometimes the wwr is faster to use, and therefore cheaper. I have used WWR a bit to work to improve shear capacity while also providing something like "scaffolds" for top mats to help with assembly... that definitely helped speed of production.
Great video again btw (refreshing as time is coming for testing!), more to my point with the wwr though, we could hypothetically use wwr to get a "bar" smaller than #3 as you were talking about shortly after timestamp 14:00 of this video. Situational use still, and won't always be the best choice, but I think wwr could be a good candidate to consider when we want a smaller "bar size".
First I want to thank you about this video , second what do you think the beat book to learn reinforcement concrete design according to aci i try nilson book but have a problem with example in this book not practical
Thank you, I am waiting examples according aci 318-19
i gotta get on this! after my exam in October maybe!
@@Kestava_Engineering I wish you success
Are you sure for Table 9.7.6.2.2 from ACI 318-14, we are looking at phi Vs and not just Vs? In the table it says just Vs.
you're correct - it is just Vs. however i like to compare with phi included so i can quickly compare by doubling the concrete capacity. adding phi to both sides of the equation should not change the comparison. but if you disagree you can / should use Vs for sure!
@@Kestava_Engineering Thanks for the response!
Why isn’t the top and bottom of shear stirrups considered, you times the leg’s area by 2? Thank you
you only get to use the steel that is going through the shear plane. the top and bottom of the shear stirrups do not cross the shear plane. think about how a beam fails in shear and the look what shape the shear plane is. hopefully this helps! i can talk a little further in this
If 0.5 phi Vc is greater than Vu, does that mean we wouldn’t necessarily need shear reinforcement since the concrete shear strength is adequate?
yes! but make sure you check all other requirements from that code section, just to be safe.