Request: a video on foam concretes (cellular concretes), second to that something about basalt fibre rebar, another thing that is very interesting to me is stay-in-place formworks
@TylerLey6 жыл бұрын
Thanks a bunch. I have worked on the cellular concrete video but I am still trying to figure out what to cover first. I am making a bunch of videos on durability of concrete. Watch out for those. I don't know a lot about basalt fibers. I know a lot about stay in place forms. What exactly do you want to know?
@32353235e6 жыл бұрын
About cellular concrete. I think, a good thing to cover is current impediments for use in the areas where the heat and sound insulation matters the most - residential construction. Question I myself hear a lot is "if it is so awesome at saving time, energy and money, why it is not being used everywhere?" I myself can only answer that in general terms: need to work on building codes, lax enforcement of building energy efficiency norms in richer countries, costs of bringing more specialists, and reluctance to introduce new processes when "you can still do that with plain OPC." I myself feel that the situation with their use is similar with AAMs and geopolymers - there is one family of OPC based cements, but a whole "zoo" of AAMs and geopolymers with dramatically different chemistry. On rebar, what about a talk on non-steel rebar in general? I took note of basalt fibre rebar for it being comparable in price to fibreglass, but at the same time being safer in regard to being more resistant to alkalies and acids (the common opinion that you don't have to care about corrosion with fibreglass rebar is very wrong,) This itself allows for more generous use of fly ash and other cement substitutes for whose low variability in chemical composition you can't vouch (sulphur contaminated fly ash can't be sold as construction material, but...) What I want to hear about stay-in-place formwork is a brief intro with pros-and-cons for people who aren't familiar with them, economic aspects, and novel uses in high rise residential (in exterior walls (reducing the need for scaffold work,) and interior.) Separately, I want to give a warning to all engineers that a magnesium oxide board, a material commonly used in non-removable formwork, frequently comes with excess sulfites or chlorites content, and water permeability varying from batch to batch. I will also note that all three of these work in synergy when I comes to cost and energy efficiency: basalt fibre rebar can be used in porous cellular concrete because it is not that corrosion sensitive, can be left "naked," and does not conduct heat well (very important in slabs); stay in place formwork provides additional mechanical protection to softer cellular concrete, and allows to cover slab ends. I'm bringing all that up because I noted that use of these got picked very well in Easter Europe for residential construction in the last decade.
@TylerLey6 жыл бұрын
All good points! Sounds like you should make the video(s) =). There is a lot of concern with development length of rebar in cellular concrete. This is a big deal. Also, if you use cellular for insulation then it is tough to get to pipes and electrical wire to fix them. Basalt rebar is not available everywhere. I have played with it a little and it looks promising. There is a lot of good work that is going into changing the building codes for non-steel bar but there is a big lobby to change slowly. Stay-in-place forms are awesome as long as they are designed correctly. I agree that you can use all of these together and you could do some really cool stuff in building construction.
@ahmedimtiazzamee22884 жыл бұрын
Best playlist ever ♥
@silverclash6 жыл бұрын
the Brazilian code (NBR 6118) has already considered this reduction for many years
@TylerLey6 жыл бұрын
Thanks for the reply! I realize this is not new but many people do not understand why this is allowed.
@lukasevans55484 жыл бұрын
In your next video you should say you're a concrete stan when you introduce yourself
@jackgaydar41584 жыл бұрын
Great video. can you do "Slab on Grade"- a.k.a. "Slab on Ground", R.C.? for a storage building, rebar or wire mesh? Love the videos-excellent presentation. Thank you very much.
@kushalghosh15596 жыл бұрын
Superb video Dr Ley. Sir,A new clause in the Indian seismic code IS 1893-2016 says that the minimum dimension of a column should be equal to 20 d where d is the diameter of the maximum longitudinal reinforcement of a beam anchoring into the column,I am wondering regarding the reason behind this?
@TylerLey6 жыл бұрын
Kushal - I am not sure how they came up with those numbers but I think their intention is that you want the yielding to happen in the beams and not the columns. This helps dissipate energy in an earthquake or other extreme event. Also, if you get yielding in a column then you can lose an entire floor. That can cause progressive collapse. The 20 d seems to be a simple way to make sure the column is big enough. I have never heard that rule before.
@kushalghosh15596 жыл бұрын
Sir,Thank you so much for the reply .Sir,the strong column weak beam theory is an underlying factor behind most of the recent changes in our codes. Even STAAD PRO V8i select series 6 version seems to have integrated this into the design. And sir,the clause that i mentioned is in IS 13920-2016,OUR CODE FOR DUCTILE DESIGN and not IS 1893-2016,as i had mentioned earlier,sorry for the mistake.