If it is a small opening, monolithically poured, and a deep lintel to justify "arching" effect, it should be acceptable to assume a triangular distribution.
12' opening for a 6" poured concrete wall reinforced with 6x6 fibermesh. It is a new cut in an existing wall. Only a 1 story concrete building with a concrete joist deck supported by concrete columns exterior and interior. Loads for the roof system are transferred to the vertical columns. The wall has no point loads and is not loadbearing. The load carried is basically 5' of wall above. Thanks for your reply on this. For the load distribution, I'm curious as to whether triangular distribution is viable in this type of setup. I deal mainly with masonry block and am new to renovation of buildings of this type.
The Code does not allow plain concrete except for elements that bear directly on soil. I would use a steel lintel of some sort--perhaps a channel each side of the wall.
You could apply the same rules for arching action as for a masonry wall. Those rules however, require the height of wall above the opening to be greater than half the lintel length. If you have 5 ft of concrete above a 12 ft long lintel, you don't meet that criteria.
You can consider a couple of point loads at each side of the opening. If you consider dwls from the beam to the wall, the ones on each side of the opng are likely in tension... just to maintain continuity.
