Concrete panels - do they flex?

[Midnight plough boy]

I'm putting up a new grain store. On floor store with concrete panel grain walls. Panels are 3.6m high (3 x 1.2m panels) 180mm thick. On the back wall they are 4m in length. On the outside at the back i'd like to build a small blockwork shed to house the drier controls (3m x 3m).

If I build this shed right up against the grain store (in effect using the concrete panels as the back wall of the shed) and then fill the store with grain to 3.6m will the panels flex at all and push the blockwork off the mortar?

 

[RWG Contracts]

I'm putting up a new grain store. On floor store with concrete panel grain walls. Panels are 3.6m high (3 x 1.2m panels) 180mm thick. On the back wall they are 4m in length. On the outside at the back i'd like to build a small blockwork shed to house the drier controls (3m x 3m).

If I build this shed right up against the grain store (in effect using the concrete panels as the back wall of the shed) and then fill the store with grain to 3.6m will the panels flex at all and push the blockwork off the mortar?

I believe they do flex a bit yes

 

[frustratedfarmer]

That's quite a thickness. Have 150 mm which flex a little.

You may be better of offsetting the block work by maybe 20 mm and then squirt the Panal sealant in the gap so it will expand if needed.

May not be rodent proof though long term?

Could fit some tin strips on sliders if you want a pukka job but lots of hassle

 

[TomB]

On this subject when setting panels in concrete floor should they have an expansion joint so they can flex rather than crack? 150mm panels set 50mm into floor. Grain to 4m+

 

[RWG Contracts]

On this subject when setting panels in concrete floor should they have an expansion joint so they can flex rather than crack? 150mm panels set 50mm into floor. Grain to 4m+

I always use fibre board on panel anyway, gives concrete room to expand and contract

 

[Unbrako precast]

Panels do flex a small amount when heavily loaded . 5% of the length is the maximum they should be flexing without causing a problem, i.e 5mm per metre (roughly 30mm on a 20' panel ).
In the case of the building against the panels I would leave a gap and foam / mastic as suggested or have an overlapping flashing fixed only to the panels. albeit in actual fact it may never move.
As far as concreting the bottom row in .
An engineer would say it was a bad idea but I have never seen it cause a problem , it is certainly the best way of sealing round the bottom. In the ideal situation the first row that is set in should have a flat top to allow the others to flex separately. But if you use 2x 1.5m panels and a 1m panel the force won't be very great above the first row.
If you use hardboard it needs to be underneath as well or the concrete catches the groove anyway.

 

[Mrfarmjunk]

What are people's thoughts of using 6 inch panels as a retaining wall to hold hardcore back? Will they flex?

 

[Unbrako precast]

They should be fine for that .

 

[Forever Fendt]

What are people's thoughts of using 6 inch panels as a retaining wall to hold hardcore back? Will they flex?

depends on the depth of fill and the type of fill and how its compacted

 

[JMTHORNLEY]

How and what is the best way to compact against prestressed panels 8" thick to use them as a retaining wall?

 

[Forever Fendt]

I take it you are putting the smooth side to the fill ? and not relying on the clips , your panel supplier should advise on the capacity and more importantly the the min bearing on the ends, if you are concreting the yard behind them put min 12mm flexed behind the panel to form a compressible edge for the loading or the flex in the panel will split the top of the yard behind,Dont underestimate the size of the base for the steel uprights

 

[Forever Fendt]

How and what is the best way to compact against prestressed panels 8" thick to use them as a retaining wall?

And think about any water from the top yard it needs to escape rather than build up behind the wall

 

[JMTHORNLEY]

12mm flexed? I will be securing them into 203X203 56KG RSJs so the internal web will be 206/207mm on bolt boxes in 1000X800x600 bases, that be enough? 8” thick to 3M high over 23ish M
Was thinking batter to within a foot then 50/75mm clean between the fill and panel gently rolled in? I will have an 8”DIA ground pipe behind the wall to move the water away into an existing land drain that takes away water behind an existing wall

 

[Forever Fendt]

12mm flexed? I will be securing them into 203X203 56KG RSJs so the internal web will be 206/207mm on bolt boxes in 1000X800x600 bases, that be enough? 8” thick to 3M high over 23ish M
Was thinking batter to within a foot then 50/75mm clean between the fill and panel gently rolled in? I will have an 8”DIA ground pipe behind the wall to move the water away into an existing land drain that takes away water behind an existing wall

the base does not sound big enough if i understand what you are proposing to do correctly (Flexcell ) compressible foam strip

 

[Forever Fendt]

12mm flexed? I will be securing them into 203X203 56KG RSJs so the internal web will be 206/207mm on bolt boxes in 1000X800x600 bases, that be enough? 8” thick to 3M high over 23ish M
Was thinking batter to within a foot then 50/75mm clean between the fill and panel gently rolled in? I will have an 8”DIA ground pipe behind the wall to move the water away into an existing land drain that takes away water behind an existing wall

Whats behind the retaining wall ?

 

[JMTHORNLEY]

The new yard area, we were going to pour the wall and shutter it but this is looking my only way. I have sent over pictures and calcs to the panel supplier and they are confident they will hold back the weight

 

[Forever Fendt]

If you are using the retaining wall as a split in levels, A yard on the bottom side and one on the top you could tie the steel posts into the slab that is on the higher side so restraining the steels at above ground level then they will not move

 

[JMTHORNLEY]

Yes that is part of the plan, also they are only 4M in length to try and give some more strength over a shorter distance

 

[dannewhouse]

just build 3 walls and tag onto existing?
if so stretch building size a little to match steelwork? then as said leave a little gap filled with foam or sealant.