Thai "standard" cement floor strength?

[Tagged]

I am building a waterstation, and need to know how many cm cement to carry 3 500 kg pr m2. The ground is flat hard packed land, going to use gravel, sand and 4 mm steel rebars mat. I said I wanted thicker steel bars, but, they said this would do, and also max 10 cm? 

 

Anyone? 

 

Rebar simular to this one, but 4 mm. This is for the barn floor. 

Edited February 3, 2020 by Tagged

[canuckamuck]

I would do 10 cm but if you are worried you could up it a bit. If you want it to be really strong give it as much time as possible to cure before you start building on it. At least several days

[cooked]

Putting that mesh in will be sufficient, if there is a point load anywhere then you can always chuck in a bit more at that spot. Personally, I would do 12 cm or even 15 cm, that's not going to cost much more time or cash.

[carlyai]

8 minutes ago, cooked said:

Putting that mesh in will be sufficient, if there is a point load anywhere then you can always chuck in a bit more at that spot. Personally, I would do 12 cm or even 15 cm, that's not going to cost much more time or cash.

 

5 hours ago, canuckamuck said:

I would do 10 cm but if you are worried you could up it a bit. If you want it to be really strong give it as much time as possible to cure before you start building on it. At least several days

@Tagged What are the dimensions of your waterstation, so I can compare it with the pool I built. 

[Tagged]

34 minutes ago, carlyai said:

 

@Tagged What are the dimensions of your waterstation, so I can compare it with the pool I built. 

Two waterstations with both loads about 3t pr m2

 

4 x 4m = 16m2

[carlyai]

1 hour ago, Tagged said:

Two waterstations with both loads about 3t pr m2

 

4 x 4m = 16m2

OK I think I see that you are building a floor to support those IBC containers. I imagined you were building an inground concrete tank, something like my pool construction.

In that case I think you have good answers already. ????

[canopy]

6 hours ago, cooked said:

 I would do 12 cm or even 15 cm, that's not going to cost much more time or cash.

Using more than needed is just wasted materials sitting on the ground doing nothing. I find this thread a lot like the blind leading the blind. All a smart person who wants peace of mind and the job done right has to do is go to the local amphur and the engineer there will calculate the answer quickly and probably free too. For everyone else, feel free to keep on guessing/hoping/wasting. Totally unnecessary.

 

[Tagged]

56 minutes ago, canopy said:

Using more than needed is just wasted materials sitting on the ground doing nothing. I find this thread a lot like the blind leading the blind. All a smart person who wants peace of mind and the job done right has to do is go to the local amphur and the engineer there will calculate the answer quickly and probably free too. For everyone else, feel free to keep on guessing/hoping/wasting. Totally unnecessary.

 

You helped alot, so thank you sir ????

[farmerjo]

You going 2 or 3 high with the IBC's.

On the IBC it says max load on top 1650kg's.

[Tagged]

12 minutes ago, farmerjo said:

You going 2 or 3 high with the IBC's.

On the IBC it says max load on top 1650kg's.

Going to buy new 6000 liter tanks, but put the ibc only two in hight, and if I would put 3, I make sure no more than 1600 liter on top of the first one. Thanks for our input. I read somewhere it was possible to stack them 3 in hight, but still not convinced to do it yet. 

[Kwasaki]

13 hours ago, Tagged said:

Anyone? 

Be safe make sure ground is compacted well and do a 200mm slab.

Give proper time for cure and cover slab from sun while slab is curing.

[murrinman]

thin concrete cracks after you cant fix it build it once build it strong 200 mm or 20 cm as the thais work in 10 mm rod is cheap comes in 10m lengths 300 mm centres 2 layers  compact well and cover arfter pouring and water cure twice a day for a week strong as a mallee bull for sure 

[cooked]

17 hours ago, canopy said:

Using more than needed is just wasted materials sitting on the ground doing nothing. I find this thread a lot like the blind leading the blind. All a smart person who wants peace of mind and the job done right has to do is go to the local amphur and the engineer there will calculate the answer quickly and probably free too. For everyone else, feel free to keep on guessing/hoping/wasting. Totally unnecessary.

 

Thanks. So I'll just send my civil engineering certificate back as it isn't a blind bit of use, and will ignore what I learned in over 40 years of construction. 10 cm is so thin that the least variation will lead it to being 7 or 8 cm, especially in Thailand, and as I said the difference in cost will be insignificant.

CALCULATE for a concrete slab? Ye gods...

[canopy]

On 2/5/2020 at 11:52 AM, cooked said:

CALCULATE for a concrete slab? Ye gods...

You lost all credibility with that comment and it questions your credentials. I personally will never take your advice on anything if this is your mindset. I hate to be the one to tell you that in your 40 years you missed out that there can be factors other than live load in computing the final thickness of a slab. And I don't understand your overall objection that the guy should NOT ask a local expert for free advice. The poor guy has been told the slab should be 10, 12, 15, 20 cm already. In the 21st century there is simply no need for wild guesses that might not work or wasting money for nothing. Do it to a safe thickness calculated by an expert and sleep well at night, no disasters to repair, cheap, end of story. I am not saying your answer is wrong, just that your methodology of computing an answer without considering all the factors is suspect.

 

[seajae]

the last person I would trust to give the dimensions needed would be a thai engineer, you only have to look at the amount of building collapses etc here to realize they are not that good. Really need to look at western standards to get a better idea of the required dimensions and thickness for it to last more than a year or 2 using thai methodology/standards

[Tagged]

I just aggreed to buy a cement mixer at Thaiwatsadu at 27 500,- with engine, and got 30 baht discount pr m2 ???? As well with the machine the quality of cement will improve. Slurry mix one bag of cement, two sand three gravel.

 

will do do 7 cm in wharehouse, 10 cm on gravity feeding station max payload 2t pr m2, pumphouse 12cm with max payload 3,5t pr m2! Should be more then enough with 4mm  iron, matt, and squere steel bars around. 
 

 

 

Edited February 7, 2020 by Tagged

[canopy]

Why wouldn't you use CPAC for this? CPAC is something I absolutely love about modern Thailand. You can order concrete to your exact strength specifications, be sure the proportions are perfect, the mixing is perfect, additives can be requested, no need for a huge machine sitting around your property, it makes the job go so fast and easy, and you get a receipt signed off to your exact specs if ever anything is wrong. CPAC charges for delivery for very small loads but it's very worth the few hundred baht.

 

[canopy]

47 minutes ago, seajae said:

the last person I would trust to give the dimensions needed would be a thai engineer, you only have to look at the amount of building collapses etc here

Anytime there is a collapse in Thailand I see the same reason over and over: the workers didn't follow instructions. And for small projects no engineer is used and the guess work was a failure. When I asked an engineer at my local amphur a question he referenced western specifications and translated them into thai for free and quick too. Very impressed. I do like doing my own calculations when I can but for most people that is too much of a bother so leveraging a local expert for free makes a lot of sense. While it is true the quality of the engineer can be suspect, asking any engineer here is surely a vast improvement over a novice making a wild guess. Like an experienced chess player vs a novice, the outcome will be very predictable.

 

[cooked]

1 hour ago, canopy said:

You lost all credibility with that comment and it questions your credentials. I personally will never take your advice on anything if this is your mindset. I hate to be the one to tell you that in your 40 years you missed out that there can be factors other than live load in computing the final thickness of a slab. And I don't understand your overall objection that the guy should NOT ask a local expert for free advice. The poor guy has been told the slab should be 10, 12, 15, 20 cm already. In the 21st century there is simply no need for wild guesses that might not work or wasting money for nothing. Do it to a safe thickness calculated by an expert and sleep well at night, no disasters to repair, cheap, end of story. I am not saying your answer is wrong, just that your methodology of computing an answer without considering all the factors is suspect.

 

I wouldn't give advice to someone that imagines that he knows it all anyway. The expression "blind leading the blind" wasn't a good start and was bound to get anybody's hackles up, which was probably your intention

Bye, oh banned one.

[Tagged]

1 hour ago, canopy said:

Why wouldn't you use CPAC for this? CPAC is something I absolutely love about modern Thailand. You can order concrete to your exact strength specifications, be sure the proportions are perfect, the mixing is perfect, additives can be requested, no need for a huge machine sitting around your property, it makes the job go so fast and easy, and you get a receipt signed off to your exact specs if ever anything is wrong. CPAC charges for delivery for very small loads but it's very worth the few hundred baht.

 

The cement truck do not have access to the land, and also many projects spread out on 3,5 rai. 
 

Anyone doubt 12 cm concrete on hard packed dirt filled with gravel, sand, iron as described? 
 

I do not see the reasons to start shouting in this tread? 
 

He also discounted 30 baht pr m2 (orign 100 baht pr m2) so will be getting 10 000,- bath discount on the projects we have started. Later we will rent it out to same guy for 20,- m2 he uses it for. 

Edited February 7, 2020 by Tagged

[canopy]

32 minutes ago, cooked said:

I wouldn't give advice to someone that imagines that he knows it all anyway

Quite the opposite. I don't know it all. Since you haven't noticed I will point out for you I have made no claims on what is needed, nor claimed who is right and who is wrong. Instead I recommended a methodology to consult a local Thai expert free of charge for those who want to facilitate a good quality result on such a project. Amazing how this can be such a controversial idea. Too many projects are done wrong in this country which results in wasted time, money, safety issues, longevity issues, and just looks bad and works bad which is completely unnecessary and avoidable. I firmly believe asking this question here is like the blind leading the blind. The wide variety of answers from people with so little knowledge of the project or hydrostatic pressures is evidence of this. I am here to learn and provide helpful advice. I understand not everyone shares these goals.

 

[jany123]

Given your pictures, the ground alone will support your weight loading, so getting anal about how much load you can put on your slab is OTT... rule of thumb for a driveway is 100mm (150-200 for a commercial driveway/ apron... think full petrol tanker weight)... even with that skinny reo... 100mm will be plenty. (Don’t forget edge thickening and expansion joints)

[Tagged]

1 hour ago, jany123 said:

Given your pictures, the ground alone will support your weight loading, so getting anal about how much load you can put on your slab is OTT... rule of thumb for a driveway is 100mm (150-200 for a commercial driveway/ apron... think full petrol tanker weight)... even with that skinny reo... 100mm will be plenty. (Don’t forget edge thickening and expansion joints)

I have so far stacked two IBC containers on top each other with no problem. Even trough the rainy season. 

[Dumbastheycome]

1 hour ago, jany123 said:

Given your pictures, the ground alone will support your weight loading, so getting anal about how much load you can put on your slab is OTT... rule of thumb for a driveway is 100mm (150-200 for a commercial driveway/ apron... think full petrol tanker weight)... even with that skinny reo... 100mm will be plenty. (Don’t forget edge thickening and expansion joints)

Best answer IMO. Especially the edges.

[jany123]

34 minutes ago, Tagged said:

I have so far stacked two IBC containers on top each other with no problem. Even trough the rainy season. 

Right... which brings you to the real problem... rain (wind, run off and erosion). The land appears to lend itself to drainage, so this might not be an issue, but wind will be, to which end, I’m wondering what anchor method your using on those concrete posts. Are they driven?

[Tagged]

1 hour ago, jany123 said:

Right... which brings you to the real problem... rain (wind, run off and erosion). The land appears to lend itself to drainage, so this might not be an issue, but wind will be, to which end, I’m wondering what anchor method your using on those concrete posts. Are they driven?

I have dikes around, which I will now cement to.

 

 

 

[tjo o tjim]

The sub-base preparation matters more than the slab thickness, but conventional wisdom is that you want at least 5 cm cover for the steel to limit corrosion, so 10cm is the minimum depth.  With 20cm I would do two courses of mesh, 15cm I would just have one in the middle.  

 

If this just needs to last 5-10 years, 10cm is fine.  If you want to make sure it will last 20+, add thickness.  If you have filled in the ground to level it out then add thickness.