concrete padstones

[tchconsult]

I have just designed a concrete padstone to spread loading from twin steel beams, overall width 300mm, onto a concrete block wall using BS 5628 and with this resulting in a width of 800mm and my intention would be to make the pad 250mm deep, ie, allowing for a 45 degree spread thro' the pad. As a check I have re-done the design to Eurocode EC6, and although the required width remains the same, I get a depth of pad of 433mm, ie with a 60 degree spread. Has anyone any ideas why the eurocode opt for such a conservative spread thro' the concrete.

 

[csd72]

I am not yet a eurocodes expert but:

Where do you get the 60 degrees from, it is my understanding that this is for masonry and I cannot see anything in EC6 that mentions padstones.

I would treat it as an unreinforced concrete member in accordance with EC2 section 12.

 

[ishvaaag]

A deeper seat is understood to be able to transfer (notionally) the loads more uniformly towards the ends (i.e., the assumption of the load being spread uniformly under the seat becomes somewhat more believable).

Yet this intent is somewhat defeated even with the stiffer deep seat by the rigid support of the blocks under the seat, that takes actually the load in more concentrated way than notionally -unifomly sometimes- assumed in the calculations.