starter bars construction details

Question

starter bars construction details

Nosa2021 (Civil/Environmental)

(OP)

21 Oct 21 10:03

I would really like to know what do you guys usually do/suggest in situations like this.

I have to connect a new RC grade beams (500 mm depth) to existing RC grade beams (450 mm depth). We don't have structure details for the existing grade beams only we know that they contain 5T16mm in top and 3T16 in bottom in support and the opposite in the midlle span.

I will connect RC beams to an existing beams like this: drilling holes in existing beam, then epoxy + rebars.

What I'm wondering is how to make sure that new starter bars will not cut or damage the exist steel bars. Do you guys construction details to show the method statement in support and middle span?

I will appreciate any suggestion, advice, photo or sketch.

Thanks in advance.

SwinnyGG (Mechanical) · Answer 1 · 2021-10-21 14:16:47

Even if you had construction details, they won't mean much unless you have infinite trust in whatever unknown rod buster/concrete crew constructed the existing structure.

GPR or ultrasound will tell you where the existing bar is and allow you to miss it with new holes.

hokie66 (Structural) · Answer 2 · 2021-10-22 03:45:14

What makes you think that dowel bars will be enough to transfer the load from beam to beam? What reaction do you need to develop?

BridgeSmith (Structural) · Answer 3 · 2021-10-26 22:58:40

We have learned through painful experience to never trust epoxy anchorage in tension applications. If you need a moment connection, I advise chipping away the concrete to expose enough of the existing bars to mechanically splice to the new bars.

Rod Smith, P.E., The artist formerly known as HotRod10

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starter bars construction details