I am sat in my office pondering, there is a building site across the way and they have had two deliveries this morning. I presume the mix is ordered and tested before dispatch, its the water thing that interests me, the driver uses a hose to swill out the drum and wash his chutes etc, how much water do they carry, is it worked out scientifically or is it just a tank and they wash till its done.
Doesnt it spoil the concrete viscosity already delivered?
Ring the firm that delivered it pal. Or here’s a number for Hanson, they’d be able to help.
Very helpful answer from MikeDick from Bristol (not) This is a forum, if you don’t know how it works google it!
Assuming it works there, the same way it works here and there’s no reason to think it’s any different; the components, sand, rock, cement and any other additives are calculated by computer. The driver adds water as it’s mixing. Getting the right slump (viscosity) is a matter of experience. The slump is tested and recorded before the truck leaves the stand.
Water is not supposed to be added before discharge, but often is at the request of the concreters during or before unloading, as it makes their job easier.
Wheel Nut:
I am sat in my office pondering, there is a building site across the way and they have had two deliveries this morning. I presume the mix is ordered and tested before dispatch, its the water thing that interests me, the driver uses a hose to swill out the drum and wash his chutes etc, how much water do they carry, is it worked out scientifically or is it just a tank and they wash till its done.Doesnt it spoil the concrete viscosity already delivered?
The slump…
Is determined at the mixing plant.
You can add a small quantity of water to the mix on site if they ask. Doing large warehouse floors, the concrete team would usually ask for it to turned into ‘banana juice’ because it’s much easier to cover with.
Leave yourself with enough water to clean your chute and the top section. But no matter how much you wash down, eventually you’ll spend a weekend hammering concrete out of your drum and off your chutes.
Short answer, I don’t know how much water we carried. 50 gallons possibly?
On big jobs, particularly in hot weather, the concreters will instruct the driver to “■■■■ it up”.
Thank you, that explains a lot, is the water in the round tank at the front of the drum, or is that hydraulic oil?
Sent from my iPhone using Tapatalk
Yes the round tank in front of the drum is for water, normally holds 300 litres
Wheel Nut:
Thank you, that explains a lot, is the water in the round tank at the front of the drum, or is that hydraulic oil?
What Adamski said.
Where the yellow arrow is, is usually always the water tank, the blue arrow underneath is the hydraulics to turn the mixer.
Things called shear couplings are always handy to keep especially in cold weather if it wasn’t drained off properly to prevent wrecking the water pump.
mixertruck.co.uk/products/shear-coupling
MikeDBristol:
Ring the firm that delivered it pal. Or here’s a number for Hanson, they’d be able to help.
I doubt they would even know or be interested.
Wheel Nut:
Doesnt it spoil the concrete viscosity already delivered?
From what I’ve seen , washing out is usually done away from the pour, maybe in an unused corner of the site.
isaac hunt:
Wheel Nut:
Doesnt it spoil the concrete viscosity already delivered?From what I’ve seen , washing out is usually done away from the pour, maybe in an unused corner of the site.
That was the main reason for my question, these washings were going straight into the same place as the pour. I haven’t had much of anything to do with construction, aggregates or bricks.
Sent from my iPhone using Tapatalk
On M/Way construction, there is normally a skip, with a plastic liner for wash out.
isaac hunt:
Wheel Nut:
Doesnt it spoil the concrete viscosity already delivered?From what I’ve seen , washing out is usually done away from the pour, maybe in an unused corner of the site.
As others have said most site people want it as wet as the can.
It’s not the viscosity that is the issue it is the strength, more water weakens the strength unless more cement is used which increases cost or wra (water reducing agent) is used but the mix designs are usually overstrength anyway.
A few litres in a footing etc is neither here nor there, not best practice. Chutes can even be washed off in a wheelbarrow or bucket if one is available no issue.
