Where to buy a slump test cone (kit)

[pferdy62]

Does anyone know who sells slump test cones?  It would be great if someone knows a retailer around Chiang Mai.

On the same thought, if anyone knows where to buy the concrete sample cylinders that are used to produce samples that can be tested for strength it would be a great help as well.

 

We are about to start building a house for a friend and want to make sure that the concrete is to the correct specification.

 

Thanks everyone.

[Lamkyong]

and if the concrete does not meet spec what then ?  also do you have a test rig  for tubes 

i admire your proposed thoroughness   plan but good luck  with the slump test by the way the items you look for are on ebay shipped from H.K

[carlyai]

CPAC concrete comes with a guarantee and thet give you some paperwork. Don't know what it mean if your house falls down later.
Make sure you get the CPAC concrete. The supplier if CPAC concrete has to have quality control etc. You can tell when they start to pour that the concrete has large aggregate and looks good.
I got a recommendation about a mob that said they were CPAC , had it written on their trucks. Turns out they weren't and an empty drink bottle and some big rocks came out at the start of the first pour. F***** hopeless mob, but I don't think you'll have worried with CPAC, genuine CPAC mob.

You can see in English the slump and strength on the yellow sheet.

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[vogie]

I'm not sure if the Thai concrete companys put a retarder in the mix to combat the heat, but all the readymix I've seen comes like p!ss and woudn't pass a slump test. Concrete is easier to lay when its like water but loses its strength.

We had an extention built on the house and they mixed it by hand, I noticed they were not putting stone in with the mix, I had to remind them to add the stone.

[carlyai]

Yes add more water add more water is the cry, but not so with the CPAC quality control. I can't say for sure but I ordered 380 strength 30 odd m3 and every truck the consistency was the same. That's just by eye. We used a big vibrator and each pour worked well. I know we ordered an additive, but I think if you need a retarded added you would have to specify.


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[r136dg]

I wouldn't sweat core samples & slump tests. By the time you got the core sample results you might be putting the trusses or walls up. Like Lamkyong says; "what then". If Thais are pouring the crete they're just going to add a boat load of water & there goes your slump test, along with other things.

Like Carlyai, I also ordered from Cpac & the slumps did look very consistent. I never requested a slump or even looked at the ticket other than to see it was the mix ordered. It looked more like a 4 slump to me, every time.

Good luck!

[carlyai]

No, think your not right about the slump, to my trained Leo eye it is 4.23406 slump. [emoji38]

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[canopy]

The first thing a chang does when the truck arrives is tell the driver to add water. Lots of water. It makes the concrete flow like water and is faster and easier to work. But as you know this can create long term issues that are unwanted. You need to explain to the chang in advance about the slump test and to instead tell the driver immediately to add no water, just in case he will do it by default. Also a good idea in this case to get a concrete vibrator. Thicker concrete is more difficult to consolidate and a vibrator will do a good job. Also tap the forms to get nice solid edges.

 

I'd also agree go genuine CPAC to help assure quality. It's no guarantee but maybe less risky than others in general. In defense of some of the others there are some that also give sheets with thorough specifications about the mix and have you sign off.

 

[carlyai]

A vibrator for any substantial work is a must in my opinion.
Once you research about them, then start to look all around in towns at piers etc. you start to notice where the trapped air was when they didn't vibrate.
I'm not a concrete, and others know heaps more than me about this, but it's just my experience.

Think I have a.pic. if our vibrator bought at Global House.


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[cooked]

I did a few slump tests on concrete in the UK on motorway bridges. A colleague with me could

1: tell you what the slump test result was going to be just by looking at it, and

2: change the results without changing the strict application of the test. I sent a couple of trucks back before I was initiated in the art of not bankrupting concrete suppliers.

The point of cube testing (7 and 30 days I believe) was, theoretically, to ensure that quality was maintained throughout the construction, with penalties payable if things weren't up to scratch. Never happened.

In your case, as mentioned above, what do you intend to do if the cube strength isn't as specified? Going to court with a big company isn't a good idea in Thailand.

Tell them you want a dry mix, buy a large vibrator and learn how to use it (most people don't know how). If you are afraid of weakness of concrete mix, demand a higher strength mix.

The other solution is to buy a large concrete mixer and measure out the quantities by the bucket full.

 

If it's any help, most concreting here is done with a wet mix, as it is easier to work and doesn't need a vibrator. The main problems I have seen have been due to concrete being too thin / not being reinforced (enough)  / not having artificial joints.

Even wet mixes will ultimately give a  strong result even if not optimal. They may be more likely to crack.

 

Stop worrying!

 

 

 

[zlodnick]

When they poured the roads in our village, a government engineer who came to inspect the work, brought some test cylinders with him, so I know they have them here.

 

They filled the cylinders at about a 3 inch slump, very impressive. Then they added water and poured the road like soup!

[pferdy62]

2 hours ago, zlodnick said:

When they poured the roads in our village, a government engineer who came to inspect the work, brought some test cylinders with him, so I know they have them here.

 

They filled the cylinders at about a 3 inch slump, very impressive. Then they added water and poured the road like soup!

They did our side road like this (without the test) and the next morning, I rode my bicycle through the road along with my pack of 8 dogs.  What a mess that was.  The city had to remove almost 100m of road and start again.

[Lamkyong]

54 minutes ago, pferdy62 said:

They did our side road like this (without the test) and the next morning, I rode my bicycle through the road along with my pack of 8 dogs.  What a mess that was.  The city had to remove almost 100m of road and start again.

bloody dogs again

[eyecatcher]

If you are that beaten up about doing your own slump test you can just go to Global and buy a few red road cones. Just snip off the top point so the cone stands 300mm high.

 

My experience with slump tests was simply about checking those drivers hadnt over watered the mix.

We had a standard for general foundations and housing slabs and that was 70mm slump....maybe 75mm on the one day of summer.

 

If it drops to 100 then its sent away and the connie company have the job of draining it and a bollocking for the driver or the batch maker.

 

Cubes are more important of course; 6 required for every batch, so thats every day. 4 for crushing and 7/14/21/28 days and two spares just incase you get a catastrophic failure.(which of course you keep quiet)

 

its quite important not to get a failure so there is more attention placed in making a cube than the concrete going into a foundation. If a cube fails the client doesnt pay!!!

if the *hit does hit th fan the concrete company would alway reckon to have made a cube on the same day whic never fails of course.

 

Our site manager was the only one who would make them, not sure his secret incredient....a bag of grout mixed in or what but clients want to see all test results for some odd reason....maybe it gave them knowledge?

 

From what I have seen here, we are far too educated about the science of materials to such an extent that every little thing they do here is wrong.

 

Yes concrete is like soup, yes they have little regard for strengths, expansion joints <deleted>; rebar and wrapping mesh with 30mm cover, protect it from the sun and let it cure, water it....the list goes on

 

But I will say, their concrete is fit for purpose and its rare you see anything fall down or fail.

so stop worrying.

[pferdy62]

Thanks everyone for your input. I have gone to the local stainless steel shop where I get things made for our factory and gave them a set of drawings to make a slump cone.  

 

I am not looking for perfect concrete, just good concrete.  We are expecting a 75mm slump, but even 125mm will still be much better than the soup that they mixed by hand to make the footers.  I will also get a decent vibrator to use on the concrete.

 

[Lamkyong]

9 minutes ago, pferdy62 said:

Thanks everyone for your input. I have gone to the local stainless steel shop where I get things made for our factory and gave them a set of drawings to make a slump cone.  

 

I am not looking for perfect concrete, just good concrete.  We are expecting a 75mm slump, but even 125mm will still be much better than the soup that they mixed by hand to make the footers.  I will also get a decent vibrator to use on the concrete.

 

 I will also get a decent vibrator  mmm   bzzzzzz  why is the wife smiling 

[carlyai]

@pferdy62

 

How many meters are you expecting to pour in 1 hit and to what depth?

 

We just poured 11 m2 around 4" deep around the pool.

We usually calculate what is needed, then order under, then, calculate what's left then order.

Example: we ordered 9m3, laid that, then calculated we needed another 1.83m3 so ordered 2m3. Very little wastage at about B2000 per m3. But for that last 2 m3 you need to add a bit more water as the 280 strength CPAC is fairly boney.

Pic. shows the pour around the pool and what was left over, where some steps will go.

 

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[kamalabob2]

A stainless steel slump test cone is on the shelf in Buriram at a Hardware store. Better builders merchants could stock and may in fact stock such an item. The builders merchants store I viewed this slump test cone also sells ready mixed concrete and provides concrete pumper rental services. So maybe the OP can find the concrete slump test cone at a store that also provides ready mix service in Thailand. 

[pferdy62]

From reading many posts, it seems as if Buriram has all sorts of things that a western tradesman would want.  Unfortunately in Lampang, these things are not as easy to come by.

[kamalabob2]

Living in Buriram province I often see how easy tradesman tools are available in Bangkok or Chonburi. I used to drive to Korat for many items I now see in Buriram. But I still drive to Korat for proper cabinet fittings at a huge shop on Highway 2 with a selection of fittings I have not ever seen in Isaan. 

[kamalabob2]

Monday I went to see a couple of ready mixed concrete pour jobs of Siam City Cement aka Insee Concrete in Buriram. I can assure you that slump cones and cubes were done for every truck load as per the contracts with the builders of the new CP All warehouse on highway 226 and at an expansion of a Singha Beverage Warehouse on Highway 2074.  No one was "playing" at these construction sites and a bi lingual translator introduced me to the construction managers. Even in rural Buriram the right supplier of ready mix concrete can add plasticizer, waterproofer and your home building concrete can meet the specifications of a huge 20,000 square meter Green Building Standards warehouse. Concrete pumper trucks are easy to book for a day in Buriram or Surin in my personal experience. Pferdy62 should be able to buy ready mix concrete in the correct strength for his important project in Lampang if I can see such quality concrete on a Monday in Buriram. It is worth the effort to arrange for proper concrete in my opinion. CPAC is a fine brand yet Insee Brand  Concrete is a brand I see in many high profile building projects.   There are several types of bagged cement to consider for your home building projects in Thailand. http://www.siamcitycement.com/en/product/cement

[kamalabob2]

I was not aware until Monday that Thailand has a Green Building Institute. The CP All distribution warehouse construction manager was very clear in that the largest warehouse in Buriram was following modern building practices. Every truck that departs the building site is washed down with a high pressure washer to prevent any mud on Highway 226. 30% of the building labor I observed were women and everyone had safety gear. Full safety harness protection for the men installing the roof sections.  Every load of concrete was tested when I was on a brief tour of the construction site. Much different safety procedures than most home building sites I have visited in Buriram, yet the ready mixed concrete was the same and the autoclaved wall blocks were the exact same. 

 

[carlyai]

@kamalabob2

Good one mate. Feels good to have a good site inspection.

Invite me over when finished and we'll do a Leo slump test. [emoji3]

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[pferdy62]

Thanks for your info kamalabob2.  I got my slump cone prior to the pour of the concrete floor.  The driver of the first truck was a little startled to see the cone and he was even more upset when he was told that his concrete did not meet the required slump even after we repeated the test.  We accepted be concrete anyway because it was still a lot better than most of what we had received for other low importance projects recently, but we did write "FAIL" in big letters next to the slump section of the delivery docket.

 

When the next truck arrives about 2 hours later  the slump test was perfect.  It matches the 75mm +-25mm shown on the docket.

 

As you would expect, the builders were not happy.  They wanted to add more water to make the concrete easier to work with.  This was met with a simple "No" and everyone got down to work and we have a good strong floor now I hope.

 

Despite not using full length screeds and bull floats, they seem to have achieved a reasonably level floor.  The flatness is not as good as I would like, but I am sure they will fix this when it comes time to lay the tiles in a really thick bed of mortar.  I was worried about this as I had taken the time to run a laser level over the formwork and the spikes they had driven into the ground periodically to give them their levels.  My figures showed a variance of over 30mm between the highest and lowest points, yet they seem to have overcome this using their 1.8m hand screeds.

 

Once we move on to the next house, we will insist on doing the floor better.  While I am not looking for super flat similar to what I am used to with high reach warehouses, I do want to get a degree of flatness that will allow us to tile the floors using regular tile mortar that is only a few millimetres thick.

 

 

[pferdy62]

kamalabob2.  I have a question for you about the columns in this warehouse.  Do you know if they rendered them after removing the formwork, or where they made with a high enough quality surface finish to leave them as-is?