Blockwork on steel beam

[MIStructE_IRE]

As simple as it gets.. we see it every day of the week.. But there’s never any connection between the blockwork and the beam’s topflange to transfer lateral wind load from wall panel to beam.

With hollowblock you could easily have rebar welded and concrete filled cores. But not with solid block or old brickwork.

Do you guys spec a physical connection or rely on friction… which I expect is minimal (mortar on smooth steel!).

 

[KootK]

1) I've never done this so discount my opinion appropriately.

2) Like you, I'd be hesitant to rely on friciton unless I felt pretty confident in the dead load present. Some kind of mechanical connection certainly feels a lot better to me.

3) At first blush, I'd like to see some kind of keeper plate setup. Maybe a length of cold formed section every 48" oc or whatever, kind of like you see at joints between the underside of slabs and the tops of interior walls sometimes.

4) Any chance there's something like a brick tie in the vertical mortar joints?

 

[MIStructE_IRE]

I agree koot. However this is never done in my experience. Im thinking for example say the classic domestic rear wall removal where a new beam is installed beneath old brickwork.

Do others specify/insist on such a restraint detail?

 

[jayrod12]

I've never dealt with semi-solid or solid blocks, however our general notes indicate steel strap anchors at 32" o/c in the joints. So there's some additional friction type resistance added there.

 

[JLNJ]

Are those AAC blocks? I've never seen anything quite like those aspect ratios. And the joints are sort-of lining up like stack bond? Where is this?

I just use headed studs and grout that first course solid; however, I'm not sure in low-seismic there is any real requirement for this.

 

[KootK]

Im thinking for example say the classic domestic rear wall removal where a new beam is installed beneath old brickwork.

Depending on the nature of the brick construction, and any jointing, may it be the case that the remaining wall itself is the horizontally spanning element (girt)? My experience of these situations is that, even if the steel beam is capable of performing the girt function, it's connections at the bearings often are not.

 

[slickdeals]

Have usually shown a welded rebar for transferring lateral forces on exterior walls. On interior walls have use headed studs.

 

[WARose]

Do you guys spec a physical connection or rely on friction… which I expect is minimal (mortar on smooth steel!).

When I did commercial work what we use to do was weld a nut to the top of the beam and screw in a [threaded at the end] rebar. That bar would be lapped with the main bar in the wall. This was typically sufficient for shear transfer at the ends.

 

[MSUK90]

Is it possible to plant some concrete columns(200mmx200mm-4T12 longitudinal reinforcement with minimum required ties) at say 3m spacing?
The column rebar should be be welded to steel beam.
The wall will then be laterally supported by columns which will be supported by steel beams?

 

[Enhineyero]

I rely on friction, the code where I practice allows 20% of dead load to resist shear. If shear forces are larger I probably would use reinforced masonry. For small buildings with a decent amount of walls this doesnt seem to be an issue. It only becomes a problem if you have 2 short walls on each direction to resist lateral loads.

 

[masonrygeek]

I think the answer depends on what type of wall or frame is being designed. If this is an interior partition wall, then relying on the friction is probably all you need. The same may be true for a non-participating wall depending on its design. However, if the block are a participating element or designed as a hybrid masonry system then some of the methods listed above may be appropriate. So the answer depends, as with many things...