cement grout

Almost everything that needs to be said about concrete, cement, hand-mixing, uses and prices has been said on this forum. Please check out the contributions before posting new questions.

Moderators: Sometimewoodworker, MGV12, BKKBILL, pattayapope

cement grout

Postby HAWKHILL » Sat Nov 20, 2010 9:24 pm

Hello
I am having some problems with subsidance under my driveway I have had it redone twice and the second time they put in 6m npiles then poured the concrete on top now after 2 years tiles are cracking would putting cement grout in the void help. I have a similar problem with my deck ing slab it is also subsiding the slab was originally against the wall of the house now there is a 3/4" gap I wonder if putting grout in here would help any even if it was just to fill in the gap.
Any help would be graetly appreciated.
Regards
HH
HAWKHILL
 
Posts: 4
Joined: Thu Nov 18, 2010 5:31 pm

Re: cement grout

Postby geordie » Sun Nov 21, 2010 5:48 am

how thick is the concrete and did you put any mesh in it how big is it and could the problem be no expansion joints did you lay the drive on fill that had not had time to dry and shrink whilst it was compacting and stupid as it sounds do you have anything growing nearby that is hungry for water it could be the slab itself is diverting the water away and causing the clay to shrink grouting it will not help other than to make it a bit less unsightly my house (UK) is built on london clay and shrinks in summer heaves in winter but does it en masse as one lump i am sure with a bit more info you will get some remedial suggestions
my comments may be wrong but never deliberately
If it aint broke, dont fix it
User avatar
geordie
 
Posts: 3867
Joined: Sun Oct 12, 2008 4:39 am

Re: cement grout

Postby HAWKHILL » Sun Nov 21, 2010 9:25 pm

geordie wrote:how thick is the concrete and did you put any mesh in it how big is it and could the problem be no expansion joints did you lay the drive on fill that had not had time to dry and shrink whilst it was compacting and stupid as it sounds do you have anything growing nearby that is hungry for water it could be the slab itself is diverting the water away and causing the clay to shrink grouting it will not help other than to make it a bit less unsightly my house (UK) is built on london clay and shrinks in summer heaves in winter but does it en masse as one lump i am sure with a bit more info you will get some remedial suggestions


The concrete is about 180mm thk x 2.5m x 6m
The drive was dug up from the last time it was done 6 m piles put in concrete laid ontop no mesh on either then the tiles been ok for about 2 years now starting to crack the tiles again. I have no idea about this kind of work and was relying on the local knowledge now I am paying for it.
Cheers
HH
HAWKHILL
 
Posts: 4
Joined: Thu Nov 18, 2010 5:31 pm

Re: cement grout

Postby geordie » Mon Nov 22, 2010 3:59 am

not a huge area but an expansion joint may have helped
i am intrigued by the piles never hear of a driveway being piled before ???
you say you have movement elswhere on your decking slab so i am assuming it is settlement
damage i am being careful here as subsidence ocurs rapidly settlement over a period of time

the 180 mm of concrete is certainly a good effort and generally should suffice although having had a problem earlier i would have been inclined to mesh it as well
from memory of when it was done can you confirm its not the piles being rigid that is causing the problem ie the slab is moving and the piles are not

How extensive is the damage if its cracked across even at an angle you could cut out with a grinder following the tile line straight across and patch it place a bit or cardboard between the new concrete and the old to leave a deliberate point so it can move seperately minimizing the damage to the tiles you should end up with a wide tile joint which you can mastic instead of grout

was the house built with piles and any sign of problems there
what area are you in
my comments may be wrong but never deliberately
If it aint broke, dont fix it
User avatar
geordie
 
Posts: 3867
Joined: Sun Oct 12, 2008 4:39 am

Re: cement grout

Postby BKKBILL » Mon Nov 22, 2010 9:37 am

Bangkok is subsiding.

subside |səbˈsīd|

verb [ intrans. ]

1 become less intense, violent, or severe : I'll wait a few minutes until the storm subsides.
• lapse into silence or inactivity : Fred opened his mouth to protest again, then subsided.
2 (of water) go down to a lower or the normal level : the floods subside almost as quickly as they arise.
• (of the ground) cave in; sink : the island is subsiding.
(of a swelling) reduce until gone : it took seven days for the swelling to subside completely.


Much depends on where you live. Seems here we have piles under everything. :|

Land subsidence from deep well pumping has been affecting Bangkok for the past 35 years. Its impact is particularly critical because of the flat low-lying topography and the presence of a thick soft clay layer at the ground surface that augment flood risk and foundation engineering problems, respectively. The subsidence reached its most critical state in the early 1980s when it occurred at a rate as high as 120 mm/year. The rate decreased in the subsequent period but the subsidence-affected area expanded following the growth of the city.

This is the reason for piles and ring beams. If it isn't too bad maybe living with the cracks would be the way to go or asphalt over the existing concrete and forget about tile.
It's not who you know, it's whom you know.
User avatar
BKKBILL
 
Posts: 2943
Joined: Tue May 26, 2009 10:05 pm
Location: Mae Taeng, Chiang Mai

Re: cement grout

Postby Maseratimartin » Mon Nov 22, 2010 11:00 am

[quote="HAWKHILL
The concrete is about 180mm thk x 2.5m x 6m
The drive was dug up from the last time it was done 6 m piles put in concrete laid ontop no mesh on either then the tiles been ok for about 2 years now starting to crack the tiles again. I have no idea about this kind of work and was relying on the local knowledge now I am paying for it.
Cheers
HH[/quote]

The big problem is now your top concrete slab...no mesh...
Asuming your piles are stabile, a concrete slab on top with two layers of mesh would be stabile even you dig out the soil underneath.

You have to make now the decission to pour again a new slab on top or try to retore it....I think no builder would give you a garanty on his work knowing there is no mesh in the top slab.

If the damage are really only fine cracks then there could be one method. I used it once for a customer in Germany to restore his garage floor and lay tiles on top.... It is a plastic sheet what will be packed in two layers of tile grout and covers later the cracks...its like a bridge over the cracks...but it will not help when the cracks go on and even shift in hight...and this is the problem I estimate you will get...
See this sketch to understand the system...
cracks in floor.pdf
(54.8 KiB) Downloaded 78 times
Maseratimartin
 
Posts: 418
Joined: Mon Jul 12, 2010 10:26 am
Location: Sakeaw and Hong kong

Re: cement grout

Postby HAWKHILL » Mon Jan 31, 2011 12:23 pm

Hello all
I got some pictures of whats happening with my concrete slabs got any ideas how to fix this without re doing the whole thing
Cheers
HH
P1270426 (1024x768) (640x480).jpg
P1270425 (1024x768) (640x480).jpg
P1270425 (1024x768) (640x480).jpg
P1270424 (640x480).jpg
P1270423 (1024x768) (640x480).jpg
P1270422 (1024x768) (640x480) (640x480).jpg
HAWKHILL
 
Posts: 4
Joined: Thu Nov 18, 2010 5:31 pm

Re: cement grout

Postby otis-a » Mon Jan 31, 2011 2:48 pm

there exists a free us army corps of engineers manual for grouting soils to increase stability. I have it somewhere but the pdf very big. It is a free DoD publication. Google should be able to find it, seems most these manuals fall under a milspec, if i find it will post title
where to park dog when in town? A barking lot... :-)))
User avatar
otis-a
 
Posts: 1206
Joined: Sat Jun 19, 2010 8:26 am
Location: thai/usa


Return to cement, concrete and mortar

Who is online

Users browsing this forum: No registered users and 1 guest