Vagueness and the Aftermath - A sporadic diary

[RED-DOG]

Lol.

The post above had a picture of a Donner kebab.

[gatso]

I'm just thinking out loud, but could I use "Gatso is always right about everything" as an amazing fact?

if only more people realised this the world would be a better place

[RED-DOG]

I'm just thinking out loud, but could I use "Gatso is always right about everything" as an amazing fact?

if only more people realised this the world would be a better place

It was the only thing I could think of that you wouldn't call "Bullshit" on.

[RED-DOG]

Sigh....

Found this in my PM's

Click to see full-size image.

[RED-DOG]

I've been learning more about concrete.

According to Wiki, about 7.5 billion cubic metres of concrete are made each year. That's more than one cubic metre for every person on Earth.

Please don't bullshit this Gatters, I want it to be true.



The Romans used concrete. They called it opus caementicium


Modern tests show that opus caementicium had as much compressive strength as modern Portland-cement concrete (ca. 200 kg/cm2).[7] However, due to the absence of steel reinforcement, its tensile strength was far lower

[RED-DOG]

Less water in the cement paste will yield a stronger, more durable concrete; more water will give  a freer-flowing concrete with a higher slump. Impure water used to make concrete can cause problems when setting or in causing premature failure of the structure.


Bugger! I wish I'd known that before I put my gatepost in.

[Geo the Sarge]

Sigh....

Found this in my PM's

Click to see full-size image.

Please let this be true and if so, genius Mr Vinster

If not, still very funny Tom

Geo

[gatso]

The Romans used concrete. They called it opus caementicium

I saw a programme once on the construction of the pantheon. it must've been well made as I find concrete to be a ridic dull subject but this was fascinating

[tikay]

Less water in the cement paste will yield a stronger, more durable concrete; more water will give  a freer-flowing concrete with a higher slump. Impure water used to make concrete can cause problems when setting or in causing premature failure of the structure.


Bugger! I wish I'd known that before I put my gatepost in.

Stop it Tom!

Stereo blathering with you about concrete cover cost me so much time yesterday I was unable to write my blog, so I got up at 0500 today to make up for lost time, but I thought I'd first pop on here & see some amazing facts (complete with gatters doing his bs thing), & THEN you mentioned "slump" in concrete. GOTTA delve a little deeper there, you may have missed the importance of that.

The "slump" of concrete is incredibly important, but it is a very old-fashioned sort of test - you'll love it.

How do we test the slump im concrete? Easy. We do a slump test.

Here we go. I'm pretty sure you'll enjoy the simplicity of this.

First, though, we need the equipment - a slump cone. (see photo).

Then.....

http://en.wikipedia.org/wiki/Concrete_slump_test

[RED-DOG]

The test should be carried out by filling the slump cone in three equal layers with the mixture being tamped down 25 times for each each layer.


Outstanding!

[TheChipPrince]

Is it true about the concrete in the hoover dam?

[kinboshi]

Is it true about the concrete in the hoover dam?

What, that it's made out of marmalade?  Yep 100% true.

[boldie]

Is it true about the concrete in the hoover dam?

Yes, there definitely is some.

[gatso]

it was indeed named after the vacuum cleaner

[tikay]

So, we have done our slump test, & poured our concrete, but don't forget we have to cube it, which is NOT a mathematical term.

We have to be sure that our concrete meets the specified design strrength (so our bridges & buildings do not collapse), & to do that, we cube it.

And as concrete gains strength as it hardens, sets & matures, & it does so on a very precise & predictable pattern, we will take, usually, 6 "test cubes", & these will be crushed at pre-determined intervals - being, say, after 12 hours, 24 hours, 7 days, 14 days, 21 days, 30 days, etc. 

Soon as the pour has taken place, the cubes are collected by a man in a little van & taken to - wait for it - the Concrete Testing Laboratory. Where they get crushed.

The strength of the concrete after 12 or 24 hours does not matter as such, it's the 7 day test we really need, however, because concrete gains strength at a predictable rate, if it is a duff batch, the 12 hour crush will tell us, & THAT gives us the chance to break out that freshly poured concrete before it gets too tough. Which can be a NIGHTMARE if left beyond 12 hours.

Here's the cubes they use. Not sure if you can get the scale, but the cubes were, in my day, 6" x 6" x 6".

See also this rather plain, but excellent description........

http://www.logicsphere.com/products/firstmix/hlp/html/stre5p9g.htm