Answering Questions About the Phoenix

[@TylerLey]

You can find the video that introduces the Phoenix here: kzbin.info/www/bejne/ipfZoqqOrNmrn68

[@bobjoatmon1993]

Always gain knowledge with one of your videos, thanks

[@TylerLey]

Thanks!

[@TarekAlHelo]

تايلور ليه...انت فخم ..واعتبرك احد افضل مثيري الشغف في علوم الخرسانة...

[@BarreraRomeroIngenieros]

Thanks for the papers Tyler

[@TylerLey]

Thanks for watching!

[@sasankasekhar9735]

Excellent & very nice informative...sir...

[@TylerLey]

Thanks!

[@effectprojectekb]

Hi Tyler! Thanks a lot for your video, can you make a video about decreasing strength and Youngs modulus of concrete due to fire?

[@TylerLey]

I think I have that. Check my fire videos.

[@effectprojectekb]

@@TylerLey I have watched that, but I'm looking for formula of decreasing strength and Youngs modulus, does ACI have those expressions? Frankly speaking Russian codes have these values in table and I can interpolate them, but I would like to use clear formulas without interpolation tables.

[@TylerLey]

@@effectprojectekb I think there are too many variables that impact the strength loss. What type of aggregates did they use? How quickly did they quench the concrete? How hot was the concrete? What was the volume of aggregates in the mix?

[@robb2959]

But concrete sample in large sealed container with dehumidifier ? With weight scale and measured water in dehumidifier catch tray ?.

[@trafficsignalman]

Has ASTM taken you up on creating a test method utilizing the Phoenix?

[@elbuggo]

How will the estimate change if plasticizer was added to the mix? Is that something the result must be adjusted for?

[@ed1pk]

Has Ley done a video about dry poured concrete?

[@robnowe5464]

Do you think that price of $17K will stifle the growth of Phoenix use?

[@TylerLey]

I don't think so. What does a bad load of concrete cost on a jobsite? What does 10 bad loads cost? Here is a piece of equipment that can greatly reduce the chance of this.

[@therakshasan8547]

isn't less air better ? Even if the bubbles are micro sized and evenly dispersed why have any air ?

[@TylerLey]

You need the air for freeze thaw durability. Look at my other videos for more information.

[@maswapres]

Thanks a lot... Very interesting, are you sure all the water will be lost if you heat it? when the water mixed with the cement I thought that some of the water would react with the cement to become CSH.

[@TylerLey]

Thanks! I looked at this in a paper that I published. As long as you the test is run before the concrete reaches initial set then you will remove the water from the CSH. The paper is in the folder that I reference in the video.

[@JoshMurray-y5k]

Does the Phoenix evaporate the admixtures in the mix or how does that work?

[@TylerLey]

Yes it does!

[@sasankasekhar9735]

Sir can we called measured w/c ratio by phoenix as effective w/c ratio of the same mixture....?

[@TylerLey]

I am not sure what your question is.

[@sasankasekhar9735]

​@@TylerLey sir effective w/c ratio is same ? when we obtaned by phoenix test

[@OrenTirosh]

Is too little water ever realistically an issue?

[@TylerLey]

Yes, if your water is too low you can get autogeneous shrinkage and cracking in the concrete. This starts to happen when your w/cm is below 0.40. Also, the lower the water is the most admixtures you will need to make the concrete flowable. This will increase the cost of the mix.

[@OrenTirosh]

@@TylerLey too little water will obviously affect the concrete. What I meant is whether it’s something that happens anywhere near as frequently as too much.

[@TylerLey]

@@OrenTirosh Yes, sometimes people mess up the aggregate moisture content and they don't add enough water to the mix. This is a reason that it is tough to get consistent concrete if you don't have a way to measure the water content directly.

[@mad_dentisthd7421]

Phoenix sounds great but I don’t think it can replace concrete cylinders. As a ready mix producer, the ability to rapidly get a moisture is heaven sent. But for on the job testing to see if W/C ratio was met seems useful, but not a good indicator of strength. For example, sand moistures are too high at the concrete plant, the mix comes out very dry and oversanded, the driver than adds water to slump it, technically the mix could meet w/c ratio but no one would know the mix is oversanded and would produce a lower strength

[@zeb5478]

Yes, renegade water…… lazy concrete crews adding water to turn 4” slump into 8” slump so they can place concrete with half the work and half the crew size. It is epidemic.

[@Real_Tim_S]

Well Tyler, if only I could get you do do a compendium of evaluations of admixes and other water reducers... It feels like you're getting pretty close to being able to push out a spreadsheet and and a few simple tests to: engineer, batch, and analyze concrete for a project.

[@TylerLey]

Tim! That is a cool idea but a tall order. There are so many things that impact how admixtures perform in a concrete mixture. The cement, SCM, and temperature all play a really big role. I will keep thinking about it.

[@RichardKinch]

You ignored the important question of the diagnostic power of the metrology established by this testing. You should deliberately make faulty batches and see if the measurement properly reports the a priori facts. And do this double-blind to prove no bias. You only tested commercial batches with correct formulations, so you're not really conclusive about rates of both Type 1 and Type 2 errors. Until you do this, there is no basis to trust this testing method.

[@nobreighner]

Their stated assumption is that the mix design is consistent except for water (and air). No claim was made to measure non-compliance with a given mix design, which would be out of the scope of such a w/c measurement. The analogy would be your saying that an aggregate moisture content test is not diagnostic about the particle gradation. Of course. They tested against known w/c, from 0.36 to 0.48, testing each step from 23 to 130 times, in this testing process. If you are after 0.36, then the 0.48 measured would be faulty. If you believe that these results were revised post-test to be closer to the measured w/c, then you are very skeptical. This solves a big problem, such as with small batch plants that never really know the w/c, because they really don't know the aggregate moisture content, particularly right at the time of batching, and they often have leftover rinse water in the drum. So they continue to use slump, which is not an accurate indicator of w/c when using a water reducer, or after cement begins hydrating. And holding w/c constant, slump varies with aggregate shape, and when aggregate gradation is discontinuous. But a direct test of w/c should be able to determine more closely what is really going on in these cases.

[@RichardKinch]

@@nobreighner The whole point is to detect faulty vs correct batches. Without testing both you have no valid metrology standard established in this method. There's no assumption of correct mix; if there was, there would be no point in testing. It's possible this works, but without systematic proof it's just an unreliable method. Also, there is no characterization of how sensitive the method is to operator errors in the testing procedure. The weakest link may be inconsistent or unreliable operation in the field. Just because PhDs in a university laboratory can get results, doesn't mean a mud slinger is going to get it right.

[@TylerLey]

@@RichardKinch Thanks for the comment. I posted some field data in the first Phoenix video with field data. The coefficient of variation was pretty similar between the lab and the field. I also have data from Minnesota taken by "mud slingers" in the field with 150 or so mixes. The data is pretty close to what I show in these videos. Most of this is in the three peer reviewed papers that I listed in the link. The idea to purposefully make "random" batches and check them is a good idea but I am not sure it is possible with this method. This method always starts from the batch ticket because you need to know the amount of aggregate that is supposed to be in the mix, specific gravity, and the absorption of the aggregate. This is important because you need to know the moisture that goes within the aggregate to calculate the amount of water that is left for reaction. This means you cant' really do a test "blind". I don't think that is a big deal because most of the concrete tests can't really be used to measure a bias. If you check the ASTMs for the slump, strength, and air content none of them have a bias. Despite this, I think this test is very powerful. I think it can tell you a lot and there are people in the industry that see the value and are using it.

[@RichardKinch]

@@TylerLey You're claiming to have invented a method for detecting faulty batches, but you haven't demonstrated it on anything but proper batches. You have no proof of the validity, sensitivity, reliability, susceptibilty to operator error, Type 1 and Type 2 error rates, etc. Until you do that, this is no more serious a method than dowsing, and is not worthy of an engineering standard.

[@TylerLey]

@@RichardKinch I think you are misinterpreting what I have said. I have stated that if given the batch ticket then I can check if the water that is reported is the same as the water that is in the mix. People in practice are finding this useful. We have detected several proper and inproper batches in both the lab and the field. Other people in industry have also done this. This is why there is so much interest in this method. While it is not perfect, it provides a better tool than has existed before.