Hello
I am going to build a room using concrete form blocks. The floor slab is about to be completed.
I will be using concrete blocks measuring 50x25x30 cm (20x10x12 inches). Reinforcement is clear. I would like to mix the flowing concrete myself. A concrete mixer is available.
Now the questions: Which aggregate size should I use for the concrete? What is the mixing ratio (aggregate to cement)? What additives are necessary to achieve flowing concrete? Is the concrete truly "self-compacting," or will I need to assist with a tamping rod or a vibration device?
I need 200 liters (53 gallons) of concrete per square meter of wall surface.
Steven
I am going to build a room using concrete form blocks. The floor slab is about to be completed.
I will be using concrete blocks measuring 50x25x30 cm (20x10x12 inches). Reinforcement is clear. I would like to mix the flowing concrete myself. A concrete mixer is available.
Now the questions: Which aggregate size should I use for the concrete? What is the mixing ratio (aggregate to cement)? What additives are necessary to achieve flowing concrete? Is the concrete truly "self-compacting," or will I need to assist with a tamping rod or a vibration device?
I need 200 liters (53 gallons) of concrete per square meter of wall surface.
Steven
S
Sebastian7918 Aug 2016 09:07Depending on the size, that might work – although comfort would certainly be different. Moving it could result in...
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angoletti118 Aug 2016 12:03No offense, but the approach to measuring the quantity doesn’t seem very practical. I like working with insulated concrete forms myself and have used several hundred so far.
With an estimated 6m³ (7.85 cubic yards), that means almost 11 tons of material to shovel into the mixer and then again into the forms. So that’s about 22 tons total—not exactly ideal.
Order 6m³ (7.85 cubic yards) of water-resistant concrete, currently costing €69 per m³ (cubic yard) including VAT, then add €20 rental for the vibrator, €10 for the 5m (16 ft) drainage pipe that the driver brings for unloading, and €30 because unloading takes a bit longer.
For €500, you get all the forms filled with waterproof concrete of tested and consistent quality. Two extra guys helping with unloading: one holds the pipe, one operates the vibrator, and one is responsible for the process.
Two hours later, you can start grilling and watch the concrete cure.
I seriously doubt that once you factor in the delivery of gravel and cement and everything else involved, you’ll save more than a two-digit amount.
Don’t forget to fill the joints of the insulated concrete forms with mortar or tile adhesive before applying the bitumen coating, otherwise it won’t be very effective.
With an estimated 6m³ (7.85 cubic yards), that means almost 11 tons of material to shovel into the mixer and then again into the forms. So that’s about 22 tons total—not exactly ideal.
Order 6m³ (7.85 cubic yards) of water-resistant concrete, currently costing €69 per m³ (cubic yard) including VAT, then add €20 rental for the vibrator, €10 for the 5m (16 ft) drainage pipe that the driver brings for unloading, and €30 because unloading takes a bit longer.
For €500, you get all the forms filled with waterproof concrete of tested and consistent quality. Two extra guys helping with unloading: one holds the pipe, one operates the vibrator, and one is responsible for the process.
Two hours later, you can start grilling and watch the concrete cure.
I seriously doubt that once you factor in the delivery of gravel and cement and everything else involved, you’ll save more than a two-digit amount.
Don’t forget to fill the joints of the insulated concrete forms with mortar or tile adhesive before applying the bitumen coating, otherwise it won’t be very effective.
Hello angoletti
Thanks for the tip. Ready-mix concrete would also be my first choice. But it’s not possible. I can fill a maximum of 3 rows of bricks stacked on top of each other. The working space is very limited (at the back there is underpinning, on the left and right sides concrete walls have been raised for stabilization. I am currently pouring the floor slab in between. I have a maximum of 20cm (8 inches) of working space. Realistically, I can only apply bitumen if I first spread bitumen on every second row and then stick the Styrodur insulation board on top. There simply isn’t any more space.
I’m not worried about the few extra euros for the ready-mix concrete.
Steven
Thanks for the tip. Ready-mix concrete would also be my first choice. But it’s not possible. I can fill a maximum of 3 rows of bricks stacked on top of each other. The working space is very limited (at the back there is underpinning, on the left and right sides concrete walls have been raised for stabilization. I am currently pouring the floor slab in between. I have a maximum of 20cm (8 inches) of working space. Realistically, I can only apply bitumen if I first spread bitumen on every second row and then stick the Styrodur insulation board on top. There simply isn’t any more space.
I’m not worried about the few extra euros for the ready-mix concrete.
Steven
S
Sebastian7918 Aug 2016 13:35You still need to compact or vibrate the material – don’t forget!
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angoletti118 Aug 2016 14:26Search on eBay for "concrete vibrator." The models that look like a drill with a flexible shaft are available for around 50€. With a long hose, they cost about 150€.
There are also concrete plasticizers as additives, which is probably what you meant. However, these do not replace a compaction method; they only make it easier.
There are also concrete plasticizers as additives, which is probably what you meant. However, these do not replace a compaction method; they only make it easier.