I am not an expert in the field, but I have made a few small areas with my own lightweight concrete; and then I used 1 part cement, 3-4 parts sand, and 3-4 parts lecakulor, so quite a large volume of balls. I have not done any compressive strength tests, but it seems okay. The tricky thing with lightweight concrete is if you want to achieve a nice surface on the floor because the balls tend to float up and settle on top. I had to use self-leveling compound.
"jawen
Full member
Active: Apr 2007
Location: Uppsala
Posts: 223
Hi eestere
Sounds like an exciting project overall, so I'll try to give you some advice.
Concrete is the term when sand/stone/water and cement are mixed, meaning the finished product when you, for example, cast it. It's called cement and is the binder.
Answers to questions:
1) The cement you should use is probably Murcement A, and lime is usually present in cement; for example, construction cement contains between 13-21% lime.
2) The mixing proportions should be 70% Leca, 16% cement, and 14% water, which should correspond to about 3mpa, the same strength as standard Leca blocks.
3) Leca that you buy in a bag contains, as far as I know, nothing except they are a bit dusty because they have been rubbed against each other. (available in large bags)
Note! Do not wet the Leca balls before mixing, then mix the cement/water and pour in the mixture in small portions, letting the mixer (like a tumbler) run for several minutes before you slowly add more cement mixture and continue until they look somewhat sticky. It's very easy to get more cement mixture at the bottom of your mold as gravity causes the cement to strive downward.
Good luck and get back with the results.
Best regards, Jawen"
I imagined concrete with a high proportion of leca balls, but with Jawen's advice, you end up with a Leca block structure.
/ATW
Full member
Active: Apr 2007
Location: Uppsala
Posts: 223
Hi eestere
Sounds like an exciting project overall, so I'll try to give you some advice.
Concrete is the term when sand/stone/water and cement are mixed, meaning the finished product when you, for example, cast it. It's called cement and is the binder.
Answers to questions:
1) The cement you should use is probably Murcement A, and lime is usually present in cement; for example, construction cement contains between 13-21% lime.
2) The mixing proportions should be 70% Leca, 16% cement, and 14% water, which should correspond to about 3mpa, the same strength as standard Leca blocks.
3) Leca that you buy in a bag contains, as far as I know, nothing except they are a bit dusty because they have been rubbed against each other. (available in large bags)
Note! Do not wet the Leca balls before mixing, then mix the cement/water and pour in the mixture in small portions, letting the mixer (like a tumbler) run for several minutes before you slowly add more cement mixture and continue until they look somewhat sticky. It's very easy to get more cement mixture at the bottom of your mold as gravity causes the cement to strive downward.
Good luck and get back with the results.
Best regards, Jawen"
I imagined concrete with a high proportion of leca balls, but with Jawen's advice, you end up with a Leca block structure.
/ATW
"Quote"
Larsa
Full member
Active: Sep 2005
Age: 40 years
Posts: 493
Oops, I guess I remembered wrong.... I have a book on this and double-checked now.
Recipe:
8 parts leca, 1 part plaster sand, 1 part cement
1 liter of water / kilo of cement
"End of quote"
Oops, there should apparently be some sand in the mix.
My possibly incorrect procedure:
1. 60 liters of leca balls in the mixer.
2. Mix water and cement in a bucket with a stirrer to the consistency of porridge.
3. Pour the cement porridge into the rotating mixer until a sticky consistency is achieved.
4. Pour the cement/leca mixture into the mold.
I hope to achieve some strength, but we'll see
/ATW
Larsa
Full member
Active: Sep 2005
Age: 40 years
Posts: 493
Oops, I guess I remembered wrong.... I have a book on this and double-checked now.
Recipe:
8 parts leca, 1 part plaster sand, 1 part cement
1 liter of water / kilo of cement
"End of quote"
Oops, there should apparently be some sand in the mix.
My possibly incorrect procedure:
1. 60 liters of leca balls in the mixer.
2. Mix water and cement in a bucket with a stirrer to the consistency of porridge.
3. Pour the cement porridge into the rotating mixer until a sticky consistency is achieved.
4. Pour the cement/leca mixture into the mold.
I hope to achieve some strength, but we'll see
/ATW
The lecakulorna seem to hold together.
I previously slammed and today I applied plaster on the outside, it looks good.
Conclusion:
It is not cheaper than building with lecablock but if it’s a smaller and irregular area that needs to be filled, I think place-cast lecakulor is an alternative.
/ATW
I previously slammed and today I applied plaster on the outside, it looks good.
Conclusion:
It is not cheaper than building with lecablock but if it’s a smaller and irregular area that needs to be filled, I think place-cast lecakulor is an alternative.
/ATW