Thread: How to quantify premixed cement?

looking to pour a new driveway and i dont know how to estimate the amount of cement to order. this is also my first purchase of premixed cement and i am not exactly sure on the process. can i simply order any amount above a minmum and tell them when and where? advice sought. ignorant is me.

Measure the length and width of the driveway. Multiply those figures to get the area in square meters.
Decide how thick (high) cement pour you want to have. Multiply again.
That will give you the volume in cubic meters, that is how premixed cement is ordered.

length by width by 10cm plus gives volume. Generally 5 cubic mts to a truck load.
Remember to lift the reo of the ground. Best to poor in sections if it's a big driveway.

^ LOL beat me to it.

are there differences in quality of the premix or is it standard? ball park costs of a 5 cubic meter load?

thanks lom and jandajoy for your responses!

Originally Posted by obsidian

are there differences in quality of the premix or is it standard? ball park costs of a 5 cubic meter load?

thanks lom and jandajoy for your responses!

There are differences but you need to speak with DD or the like.

Back in Germany you could explain to the supplier what you intended doing and they'd send you the right mix. Here, I don't know.

thanks

Last time I bought it was 1100 baht a cubic metre so probably a bit more now

And don't forget you will need a thermometer, water gauge and shaker, sunshade and gin and tonic

And don't forget the deck chair

Originally Posted by jandajoy

Remember to lift the reo of the ground.

i dont understand this. clarification please.

reinforced steel. A common mistake is to lay this on the ground and then pour concrete on top. Doesn't reinforce everything. So you prepare you shuttering - border, planks or whatever. Lay down the reo then, using either little plastic "X" things or pebbles you raise the rio off the deck. This way the rio is "in" the concrete not under it.

understood -- thanks.

are u doing the rebar urself?

no. i have a thai couple who will do the dirt/sand prep, rebar and the smoothing (or whatever its called) of the poured concrete. actually, they want to do it all by hand in a plastic tub but i am suggesting the premix delivery.

what spacing should i place the rebar? size of the rebar? and, and ideas about the depth/thickness of the pour in terms of durability?

all advice appreciated.

Originally Posted by obsidian

no. i have a thai couple who will do the dirt/sand prep, rebar and the smoothing (or whatever its called) of the poured concrete. actually, they want to do it all by hand in a plastic tub but i am suggesting the premix delivery.

what spacing should i place the rebar? size of the rebar? and, and ideas about the depth/thickness of the pour in terms of durability?

all advice appreciated.

Dunno, but I know the concrete need to segmental to avoid cracking. Like slabs that can move independant to each other.

Originally Posted by obsidian

can i simply order any amount above a minmum and tell them when and where? advice sought. ignorant is me.

Don't do what my builder did.
He ordered 20 metres of concrete and it all turned up at 9.00am
It was a complete fuckup.
Tell them you want X metres in total with y metres every 2 hours

How big's your proposed driveway?

Originally Posted by obsidian

but i am suggesting the premix delivery.

Wise choice. Hand mix is cheaper but batch to batch consistency (sand, gravel, water portions) is iffy.

http://renovate.realestate.com.au/outdoors/paths-and-driveways/projects-diy/diy-laying-cement

This might be of interest to you.

Originally Posted by obsidian

Originally Posted by jandajoy

Remember to lift the reo of the ground.

i dont understand this. clarification please.

The reinforcement steel has to positioned approximately at centre level of your slab cross section. Meaning if your slab is 10cm thick lift the steel 5cm off the base preparation.

Also make sure you prepare your slab base with drainage. I usually do this by laying a sand base and or dig some water channels acoss the base area and then fill it with small rocks such as blue metal. Keeps water buildup under the slab under control and elliminates the chance of slab cracking. Expansion joints at 3-4 metre spacing also is a good idea.

Finally make sure that you spray the slab with water regularly and to slow the curing process (continue for this for 24 hours) . In this heat here if the slab goes off too quickly cracking becomes a problem.

Never had a driveway or road crack yet.

Good luck.

^ Yes sir, redimix is the only way to go, sure they want to mix it on the job and that way they can fuck off 90% of the time, 2 working and 5 watching, and every batch will be different, have cold joints every 2 meters, and it will be a real Chinese cluster fuck.

I poured my driveway and my rear deck which covered the side and rear of my house and got it done in just a few hours, graded the soil and set the forms with the top of the form boards even with my plumb line, that way the screading can be done from the top of the boards[civilized way] and not by guess work as to what is a plumb surface[Thai way].
And then I used 5" mesh reinforcing fabric instead of ReBar. and it was spaced off the ground with busted cement block chunks and it was 6" thick.
For a driveway you should have about a medium slump mix, but it does no good to tell CPAC that as they just add water til they think it is right, so every load will be different anyway, but larger batches than they would mix in a tub.

And nort, when I did mine I checked price of the material needed and the price of the redimix and it came out the same so I saved the labor of the mixing, which would have been 3 or 4 days..

However you define it, though, the bottom line remains the same: Slump is a test for the rigidity of uncured concrete. Lower slump concrete is very stiff, and higher slump concrete is more fluid.
Most people in the business agree that a typical slump for ordinary decorative concrete applications would be in the 4- to 5-inch range, but there's no hard-and-fast rule. “The slump should match the application,” says Daczko. “It could be anywhere from 1 to 10 inches depending on what you're doing. If you're paving a road, you need a much stiffer material that can stand on its own. If you're doing a wall, the flow needs to be much more fluid.” And if you're pouring a patio, it needs to be somewhere in between.

Another good idea and when preparing a slab (and particularly for the main house slab) is to lay underground irrigation and for the purpose of distributing pest and teminate poison.

All of the houses I have built I do this by buying 8-10mm PVC pipes and drill holes in the pipe at regular intervals. I create a net work of piping that covers each room in the house that joins to a main service point/ junction left and right of the house. I close off the end of each pipe and connect a snap on barb at the main junction point.

The pipes are then covered with blue metal stones and to stop the cement from closing off the spray jets, lay your cement and your as sweet as a nut.

I find this method is the best solution for the control of termites and borers. We have our own compressed air injection unit which we use and to pump insecticide through the network of pipes once a year saturating the base of you slab and with no risk to your family.

Better than having some bloke walk through your house 3 times a year spraying hazardous chemicals. My idea really works, is quite cheap to install and kills the little buggers at the source.

^ Very good idea but probably not so neccesary on a drive way.

never sell that idea in Thailand anyway as Thai do not mind bugs and ants, seems that they kind of like em in fact as I have never seen a Thai spraying to kill ants in his house.