Not getting enough strength in clc blocks

Here we discuss how to produce foam concrete and cellular lightweight concrete, admixtures for this, foaming agents, machines, recipes and so on.

Re: Not getting enough strength in clc blocks

Postby minn » Thu Nov 09, 2017 5:41 pm

Hi
Thank you for reply.

https://www.facebook.com/SMM.light.weig ... rete.block

here is my facebook page.

I will upload photos here soon.

From what I understand, I dont have steam curing process. Our weather temperature is quite hot here around 30C and above. I just cover them for 12 hrs in mould after cutting. From casting to cutting is about 6 hrs. so total 18 hrs before I remove them and store at open air space.
I wash sand and screen to small grain size less than 2mm too.

I water the block for first 7 days or so.
minn
 
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Re: Not getting enough strength in clc blocks

Postby Shaaban » Tue Feb 13, 2018 3:16 pm

Hi Mr. Alex,
thank you very much for this good information,
im from Egypt and i started my own business in production CLC Block, but i did not get good final strength, recipe was as follows
cement 53R 350 Kg
sand -4 mm 350 kg
foam self made (10 % sodium lueryl sulfate + 2 % CMC + rest water) then dilute it into water 1:40
i made it in molds then cutting after 6 hours of casting
1- so, is the problem in foaming agent, and if it is how can i get your foaming agent or good foaming agent in Egypt and what will be the price?
2- is cement is good or i can use lower grade?
3- what is your advices for sand?
4- we have not fly ash in Egypt, so im going to use some waste powder of Granite cutting process, very fine powder produced from cutting with water cooling? what is your advices, is it good or no?
Shaaban
 
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Re: Not getting enough strength in clc blocks

Postby Alex » Wed Feb 14, 2018 8:21 am

Hello Mr. Shaaban,

1. you can use sand, it is ok for foam concrete, but better to use up to 2mm size, not more.
2. if granite powder cheaper then sand, of course use it
3. I don't know Egyptian standards for cement, better to use cement without any admixtures, for example 42,5. In case cement has some admixtures they could react with foam and corrupt it.
4. foaming agent is very important, we have very good one in Russia, but it could be expensive to import - 2USD per kg + delivery + custom clearance.
Bur you should calculate - usually it is possible to decrease cement. With good foaming agent you can use about 280-300kg of cement.
Also we can come to Egypt to adjust your technology, from Russia flights are cheap.
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Re: Not getting enough strength in clc blocks

Postby Shaaban » Thu Feb 15, 2018 6:43 am

Hi, Sir
Thank you for reply, i used the following recipe

Cement 42.5R 350 kg
Granite Dust 100 kg
Sand -4mm (unwashed) 300 kg
water 220 L
Foam (83 g/L) 1 kg

Foaming agent is self made it 10 % of sodium Lueryl sulfate solved in water + 2 % Carboxy Methyl Cellelose as stabilizer.
i didnt get good strength only 12 kg/cm2

1- what is your opinion in foaming agent, and are you have any advice for it?
2- is the sand must be washed before using, and is it give big difference by washing?
3- can i reduce the cement or use another type of it to give me better results?
4- can i use cement and granite dust only, without sand?
5- must be curing done in shadow, and what is the exact curing procedure to get the highest strength?
6- i used underground water, it was contained sulfar, is it affect the strength?
7- finally, after 24 hr handling of the block to remove it from the mold and store was hard, any advice, knowing that i used cutting machine , cast 120*120*40 cm block, cutting after 6 hr, remove from mold after 24 hr of casting?
8- are you have any clear design for cutting machine, pdf or video?

im sorry for very long topic, but i will be very glad if you help me.
Shaaban
 
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Re: Not getting enough strength in clc blocks

Postby Alex » Thu Feb 15, 2018 9:59 am

Hello!

1- what is your opinion in foaming agent, and are you have any advice for it?

Better to use protein foaming agent that doesn't afraid hot weather.

2- is the sand must be washed before using, and is it give big difference by washing?

Depend on sand. If it has clay, it must be washed, but it it is clean you can use it as it is.

3- can i reduce the cement or use another type of it to give me better results?

In case you change foaming agent - yes. OR, toy can try to use 300kg 42,5cement. It could help.

4- can i use cement and granite dust only, without sand?

yes

5- must be curing done in shadow, and what is the exact curing procedure to get the highest strength?

yes. 28 days in wet condition with temperature 10-50 by Celcium

6- i used underground water, it was contained sulfar, is it affect the strength?

It could, mostly for foam, but not for sure. I recommend to check it last, after all other things.

7- finally, after 24 hr handling of the block to remove it from the mold and store was hard, any advice, knowing that i used cutting machine , cast 120*120*40 cm block, cutting after 6 hr, remove from mold after 24 hr of casting?

didn't understand

8- are you have any clear design for cutting machine, pdf or video?

no, all cutting machines for foam concrete are sucks (not for AAC)
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Re: Not getting enough strength in clc blocks

Postby Shaaban » Thu Feb 15, 2018 12:29 pm

thank you very much for your reply Mr. Alex.

Point 7 - i mean the block has been soft to handle didn't get suitable hardness to handle and store.

Point 8 - what you mean be all cutting machine for foam concrete are sucks (not for AAC), is it affect the quality negatively? or you mean using of AAC cutting machine is better?
or cancelling cutting machine and casting into small molds directly is the best? if it is how can i increase my production capacity?

finally, are you supply CLC production line, and if you do what is your lowest and highest capacity and price to EGYPT?
Shaaban
 
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Re: Not getting enough strength in clc blocks

Postby Shaaban » Thu Feb 15, 2018 12:32 pm

in addition i can't get protein foaming agent easily in EGYPT can you tell me any scientific name for it, or specific name for it help me to collect in EGYPT.
Shaaban
 
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