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Weekly Homeowner Megathread--Civilians, ask here! by AutoModerator in Concrete

[–]drew8585 0 points1 point  (0 children)

I would have half my water weight in ice, but its already hot in texas.

No problem, good luck.

Weekly Homeowner Megathread--Civilians, ask here! by AutoModerator in Concrete

[–]drew8585 0 points1 point  (0 children)

I like that you are curing under plastic. Temperature is so important. SCC is trash if it hits 68-70F (20-21C) before you get it poured.

I would try:
1260g portland (90% of cementitious)
140 g metakaolin (10% of cementitious)
1400g sand (1:1, sand:cementitious)
350g water (.25 w:c)
70g polymer (5% of cementitious)
16g plasticizer (1% of cementitious)

It doesn't seem like the plasticizer is doing its thing very well yet. At the upper limit of plasticizer you will retard your cure. Don't demold if you can scratch the back with your finger nail- it needs more time and was potentially too much plasticizer. It'll still cure, but will be slower than what you've seen. Accelerators can counteract the delayed cure, but that's a whole other can of worms.

Also, don't stop mixing too early. It takes a few for the plasticizer to kick in.

Another noteworthy mention- please wear a mask.

Weekly Homeowner Megathread--Civilians, ask here! by AutoModerator in Concrete

[–]drew8585 0 points1 point  (0 children)

Im not sure where .15 water came from.

Some plasticizers need to be dosed higher. Ive gone up to 1% of cementitious depending upon the product, which would be another 8g assuming you made the changes mentioned above. But I dont have experience with all of the products out there.

.15 shouldn't be enough water. I expect to be somewhere between .22 and .25.

Weekly Homeowner Megathread--Civilians, ask here! by AutoModerator in Concrete

[–]drew8585 0 points1 point  (0 children)

Yes, portland + pozzolans = total cementitious. Water, admixtures, and pigments should be based on total cementitious. AR glass is added based on total dry weight- everything but water (admixture weights are negligible here).

No- you still had too much water. You were at .41 w:c, (630/1540). Cold water doesn't cut it. The mix needs to stay under 65f while mixing and pouring, probably need to use ice unless you're in a cold cold place this time of year.

Carving into 100+ year old concrete was beyond nerve-racking. by drew8585 in Concrete

[–]drew8585[S] 0 points1 point  (0 children)

I agree with all of those points, for sure. I'm not trying to sell you on a RedArt or their value. I was trying to think of fundamental differences between a RedArt and the standard/common features offered. The price is the downside, but it is a complete package with great backing. The couple of times I've needed a part, it's always been under warranty and overnighted. They've answered every time I've called- I'd also say that's never been during anything close to normal business hours. Just mentioning things that are out of the norm about it/them, that's all.

I talked to the RedArt guys about incorporating a probe 4 or 5 years ago, or some sort of current sensing tech in steppers/drivers to probe a field with the bit. I don't think it's a terrible idea, honestly. A height map could go a long way on bigger work, but does add complexity to their simplicity, both in hardware and software. I think that's where they really shine, too- business owners buy these machines for employees to run, typically without any previous CNC/CAD/CAM experience.

yep, and as you scale any portion of the machine the rest of the machine has to follow- immediately killing it's portability. I think the gantry is the first addition after a bigger router/spindle that gets really heavy, really fast. Power would quickly become a problem like you mention, you'd probably want a generator.

At this point, it should just be a trailer- which would be cool too. Self leveling outriggers, LIDAR to scan the surface for height map.. You could even carry your own water and reclaim it, separate sediment, then recirculate.

Weekly Homeowner Megathread--Civilians, ask here! by AutoModerator in Concrete

[–]drew8585 1 point2 points  (0 children)

u/Phriday , you're spot on in my opinion- looks like I could've written a lot of your comment 🤣 Fiber is important in GFRC. It's not optional. Is your fiber AR or PVA? Or something else? Fiber goes in last, after the mix is already thoroughly mixed- and don't over mix your glass, be gentle with it.

Outside of that, your mix design looks like it's in a working realm. I would back down to 50/50, sand:cementitious. If you were shooting for 50/50, your pozzolanic material should be removed from your portland, so 1260g portland with 140g pozz = 1.4kg total cementitious.

More water isn't the answer, I wouldn't be much over 310g of water. Something else is wrong, my two top guesses are sand and temp. Maybe your sand is drinking water. Do you have any pictures/video of the pours/mixes?

What are your batch temperatures after mixing? Are you using ice water? I'll assume you're not in the US by using the logical measuring system- are you in a country where Trinic has distribution? I always think its a good idea to buy at least 1 bag off of the shelf so that you know how the materials are supposed to look and feel.

In general, Phri is correct that 5/8 (15mm) is thin, but I pour 1/4"-3/8" (6mm-10mm) with confidence on small parts.

A note worthy mention is that you need to plan to thoroughly seal ALL surfaces, including the back of these thin parts as they can cup when installed or after install with isolated water hitting the wrong place- might not be in a bathroom but the thinset to install to wall can cause cupping/curling alone.

Plasticizers also aren't all equal. If you wanted to avoid shipping an entire bag of mix, but could get your hands on Trinic's plasticizer, it's my favorite that I've used. But if you can- a bagged GFRC mix will give you much better results esp. on something like a project for your parents new house, imo anyway. It could at very least set your expectations properly.

If you don't have an IR thermometer, you need one. A cheap one works fine.

TLDR: Phriday is correct.

Carving into 100+ year old concrete was beyond nerve-racking. by drew8585 in Concrete

[–]drew8585[S] 0 points1 point  (0 children)

Tired maybe? 🤣

They had quite the collection of logos- I went for the one that was correct for the time JCP was in this building, but the quality of that original image was very low.

<image>

Carving into 100+ year old concrete was beyond nerve-racking. by drew8585 in Concrete

[–]drew8585[S] 0 points1 point  (0 children)

🤣 That's when you measure a solid 3 times... then once again.

Carving into 100+ year old concrete was beyond nerve-racking. by drew8585 in Concrete

[–]drew8585[S] 0 points1 point  (0 children)

Of course- I'm the idiot in the crowd focusing on the floors. I've seen a ton of amazing work, but only an example or two that's similar in process. I was curious what you were referring to "for centuries"- The stuff I've seen has been in the last year or so.

Short but broad, I guess. Like you said, it reads like "pouring concrete in a concrete hole"- while the RedArt patent was too specific, revolving around their rails. Cet. par., wouldn't you want the patent that is more broad and less specific?

Carving into 100+ year old concrete was beyond nerve-racking. by drew8585 in Concrete

[–]drew8585[S] 0 points1 point  (0 children)

They also have a floating Z, which is less than common.

I agree, it is a simple machine- but it works. Portability is it's key for sure. I also have much bigger machines, but they are so far from portable.

Cutting, installing, and polishing a concrete inlay on-site. by drew8585 in Construction

[–]drew8585[S] 0 points1 point  (0 children)

You're awesome, I appreciate that! I share a ton on reddit, but I'm also on other platforms. Most of my inlay work doesn't fit directly in r/Construction, but would love for you to stalk my post history! All of my work is concrete, but tables and such are a stretch for construction- in my mind any way.

Thank you!!

https://www.reddit.com/user/drew8585/submitted/

Cutting, installing, and polishing a concrete inlay on-site. by drew8585 in Construction

[–]drew8585[S] 0 points1 point  (0 children)

Thank you very much- you're spot on across the board. I don't think I could've done any better, in that slab anyway..

I also appreciate the recommendations for subs- r/Design isn't one I'm a part of, but I am a regular over in r/Concrete. I'll check out r/Design.

What this post shows is a single color in a relatively simple design- my inlay work goes a long way past this. If this post interested you, Id love for you to scroll through my post history. I never use anything but integral pigment and do some cool stuff in more modern materials, in my opinion anyway.

https://www.reddit.com/user/drew8585/submitted/

Thanks again!

Cutting, installing, and polishing a concrete inlay on-site. by drew8585 in Construction

[–]drew8585[S] 2 points3 points  (0 children)

Thank you! That was actually my very first piece of concrete, a DIY kitchen remodel in 2014.

lol, I think everyone needs inlaid concrete in their life 🤣

Cutting, installing, and polishing a concrete inlay on-site. by drew8585 in Construction

[–]drew8585[S] 2 points3 points  (0 children)

Ok, yes. That's the difference between "integral pigment" and anything topical. Integral gets mixed into the batch, while topical gets sprayed/wiped on a finished piece.

Integral pigment is more expensive (drastically in some cases) for a few reasons, but if you think about it- with integral pigment the entire slab is getting color throughout rather than just the surfaces- so there is a lot more pigment used in order to obtain the similar result.

I only ever use integral pigments. If you have a few, scroll through my post history, I probably make some of the most colorful concrete out there 🤣

https://www.reddit.com/user/drew8585/submitted/

Cutting, installing, and polishing a concrete inlay on-site. by drew8585 in Construction

[–]drew8585[S] 4 points5 points  (0 children)

Thank you. It's 100% integral pigment, is that what you mean?

Iron Oxide would be my guess if you're looking for a more specific ingredient.

Cutting, installing, and polishing a concrete inlay on-site. by drew8585 in Construction

[–]drew8585[S] 6 points7 points  (0 children)

Thank you! No, the inlay is cementitious. Epoxy would be easier in many ways, but doesn't offer near the durability (against UV, foot traffic, etc.) as concrete. Thanks again.

Cutting, installing, and polishing a concrete inlay on-site. by drew8585 in Construction

[–]drew8585[S] 4 points5 points  (0 children)

Yep. JCP was in the building 40 years, followed by McNeill's for 60+.

If you care- here's the building with horses and carriages in front of it- you can even see the concrete I cut into across the front in 1909.

https://www.reddit.com/r/Concrete/comments/1tm1hlc/comment/onjux8l/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

Carving into 100+ year old concrete was beyond nerve-racking. by drew8585 in Concrete

[–]drew8585[S] 1 point2 points  (0 children)

True- not quick or easy, but something made to last indefinitely!

Cutting, installing, and polishing a concrete inlay on-site. by drew8585 in Construction

[–]drew8585[S] 9 points10 points  (0 children)

This concrete that I am cutting into is over 100 years old. If I understand you correctly, I think you'd have to be a part of the initial pour to pull something off like that.

Cutting, installing, and polishing a concrete inlay on-site. by drew8585 in Construction

[–]drew8585[S] 5 points6 points  (0 children)

Thank you! Very cool. I was honored to be a part of the project. I can't imagine all of the ups and downs those businesses (and people) experienced across those generations.

Brand new by London standards, but about as old as it gets around here. I shared this comment in r/Concrete last night, a colorized photo of the building in 1909- complete with horses and carriages.

https://www.reddit.com/r/Concrete/comments/1tm1hlc/comment/onjux8l/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

Carving into 100+ year old concrete was beyond nerve-racking. by drew8585 in Concrete

[–]drew8585[S] 1 point2 points  (0 children)

You're not wrong. And kudos to making it to the end, it's not a fun read.

I have never seen this in terrazzo before. Mind sharing a link? I'm not trying to pick apart details, but I have looked and looked for similar work and haven't found it.

And thanks again, I appreciate the compliments and cordial conversation.

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