concrete pouring limitations
concrete pouring limitations
(OP)
The project I am working on has a concrete tank for an olympic swimming pool. On 2 previous projects there have been conflict as to the pour distance allowed for thje pool tank walls.
the first project the structural engineer wanted an area of no more than 5mtrs poured at any one time for the tank walls, and on the other it was 8mtrs. I have read the BS for waterproof structures and there doesnt seem to be any limitation. The engineer on my current project also wants 5mtrs , but experince tells me that the more joints there are the more potential for leaks. Please confirm whether there are actual limitations regarding the amount of concrete that should be poured in one go. Obviously we will be pouring the slab and a 150mm kicker , but want to pour the walls in maybe 2 hits rather than 5mtr runs.
the first project the structural engineer wanted an area of no more than 5mtrs poured at any one time for the tank walls, and on the other it was 8mtrs. I have read the BS for waterproof structures and there doesnt seem to be any limitation. The engineer on my current project also wants 5mtrs , but experince tells me that the more joints there are the more potential for leaks. Please confirm whether there are actual limitations regarding the amount of concrete that should be poured in one go. Obviously we will be pouring the slab and a 150mm kicker , but want to pour the walls in maybe 2 hits rather than 5mtr runs.





RE: concrete pouring limitations
RE: concrete pouring limitations
Thanks
RE: concrete pouring limitations
Construction joints are not necessary if you do it right. If you need joints structurally, then put those in and you can use them as construction joints as well.
RE: concrete pouring limitations
RE: concrete pouring limitations
Hokie66- your advice is appreciated too.
I'm aiming for a leak free structure .
Cheers .
RE: concrete pouring limitations
I would recommend reading Ciria Report 135 'Concreting deep lifts and large volume pours'
Kieran
RE: concrete pouring limitations
More important than a specific spacing is enough shrinkage and temperature reinforcing (~.005%) and staggering the pours so adjacent pours do not occur too rapidly in succession.
RE: concrete pouring limitations
RE: concrete pouring limitations
RE: concrete pouring limitations
The type of cement should also be reviewed. Some cements shrink more than others and develop more heat than others. There are specific cements that should be used for slow curing to avoid thermal cracking and expansion.
You should probably look into the various concrete admixtures that are available that can reduce shrinkage while maintaining workability. Other admixtures you may also want to look into are migrating corrosion inhibitors and liquid crystalline waterproofing admixture (essentially seals cracks when moisture penetrates - see below).
One other admixture is Hycrete (http://www.hycrete.com/). Its an interesting admixture that claims no waterproofing membranes are required. At joints they have a specialized waterstop that they can post-inject to seal if a leak occurs there.
With any of these admixtures, testing is required.
You should also be very careful about specifying moist curing for several days. This should help reduce potetntial for shrinkage.
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Aquafin-IC Admix is a liquid crystalline waterproofing admixture whose components react with moisture and free lime to grow tiny crystals that penetrate the concrete matrix. The crystals fill capillary voids and seal hairline cracks, enabling it to resist hydrostatic pressure.
RE: concrete pouring limitations
RE: concrete pouring limitations