Construction join in Continuous Beam 2

[XinLok]

I want to do a Continuous beam with 15 spans each span 5 meters.
It cannot be complete in one shot, so I have to divide the pouring in two parts.

First part 7 spans and second part with 8 spans.
For the first part, where should I stop?
should I stopped at column Number 7, or 1 m away from the column?

any advise please?

 

[dik]

Without knowing the particulars of the loading, I'd likely do my splice at 1m away from the support, or even at mid span where shear is minimal... assuming concrete.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[KootK]

1) With concrete structures, minimizing construction joint shear usually takes precedence over minimizing joint moment. So you're generally targeting locations of minimal shear for your joints.

2) I believe that ACI recommends something like:

a) Joints should be placed within the middle third of your beam spans.

b) Joints should be placed at least two, intersecting beam widths away from intersecting beams.

3) It normally won't matter which span you place the joint in so, in that respect, I'd seek to do whatever will be most expedient for your contractor.

4) Having your joint near midspan where fewer top bars may need splicing can be economically advantageous.

5) This is a handy article on the subject of concrete construction joints: Link

 

[XinLok]

I believe all my question been answered, thank you very much for your replies

 

[KootK]

The reason not to have the join at column is because of maximum reaction or shear?

1) Right over top of a column may actually be a low shear location. That said:

a) It's a location where blocking off the formwork would be a nightmare because of the presence of the column rebar passing through.

b) It's a location where rebar congestion would be a nightmare with the column rebar passing through and and all of your longitudinal bars doubled up for splicing.

2) Right beside a column is undesirable because:

c) It's a maximal shear location and;

d) Pretty much the same rebar congestion issue as [b}.

 

[dik]

messed up a bit... it's concrete... so at mid span... missed the pouring bit... if steel, then about 1/7 span... thought the 1m was the alternative.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[BAretired]

Smack in the middle would be my choice, 7.5 spans each side.

BA