PVC Hand Rail Anchored In Existing Concrete?

[psychedomination]

Hi all I assume this is a very simple question. I need to install some PVC hand rails onto an existing dock as a replacement for some handrails that have corroded.

I need some help with how to go about anchoring them down.

My methodology so far is that I will fill the PVC with concrete and either two rebar or one rebar depending on the spacing and also use hilti epoxy to anchor the rebar down into the existing concrete.
However, Do I need to cut out the existing concrete to anchor the pvc pipe down ( I am assuming this would be the method I should take) or can I just drill into the existing concrete and put the hilti in that (directly on top of the existing concrete)? If I do need to cut out the existing concrete, how do I go about determining the depth required?

Photos of thoughts attached.

I appreciate any assistance you can provide

 

[MotorCity]

This seems like a very unconventional method. First, this looks like a guardrail structure, not handrail. How do you plan to attach horizontal rails to this post? Does this arrangement resist the code required loads? Assuming this whole detail is acceptable, did you perform any calculations to determine the force in the bars? Look in your Hilti catalog and that will tell you how far they need to be embedded (note there are severe reductions for bar spacing and edge distance).

 

[TehMightyEngineer]

What's wrong with the standard aluminum or stainless steel rails?

Professional and Structural Engineer (ME, NH, MA)
American Concrete Industries

http://www.americanconcrete.com

 

[Ingenuity]

What's wrong with the standard aluminum

If it is uncoated aluminium and embedded in concrete it will corrode.

 

[TehMightyEngineer]

Very true Ingenuity.

Professional and Structural Engineer (ME, NH, MA)
American Concrete Industries

http://www.americanconcrete.com

 

[psychedomination]

Thank you for the responses so far.

@MotorCity I guess in a sense it is a guardrail, as it will prevent people from falling off of the dock. It will look exactly like the photo attached to this reply (you can see from that how the horizontal members are connected). I am aware of the HILTI embedment requirements. I was more so questioning how to go about determining the depth requirement of the existing concrete cut out shown in the second image of the drawing in the OP.

@TehMightyEngineer This is a handrail for a dock, which will therefore be exposed to an active corrosive environment. I assume my boss told me to use these materials due to this fact. Stainless steel could be an option, but would probably cost more.

 

[thaidavid40]

Is the entire interior of this structure filled with concrete, or just the vertical posts? I don't know of any ESR reports, or any testing that verifies the capacity of the solvent-welded joints to handle the code-required minimum design live loads on guard rails. How have you gone about proving engineering-wise the suitability of this assembly to meed code-required loads? I am most interested in how this is done. If I were a code official, I would want some definitive engineering analysis backup before I approved a design like this.
Dave

Thaidavid

 

[oldestguy]

I'd put a re-bar in the PVC, fill the whole thing with mortar. Assuming the PVC is 4 inch O.D. Then drill 5 inch diameter holes into the slab or through it. Then, set the PVC unto that and secure it with some form of "glue" be it mortar or other. Exposing the re-bar to moisture at any place is inviting corrosion. Combing the re-bar with the PVC and mortar is stronger than re-bar alone.

 

[dvd]

The car in the picture implies the use of these guardrails as bollards. I understand the appeal of the inexpensive materials, but this arrangement is not going to resist much of an impact, its main failure mode is brittle fracture, it has susceptibility to uv, it is going to have a serious mis-match on thermal expansion with concrete. etc.

The following discussion seems relevant - thread507-244205.

 

[racookpe1978]

Well, you're not "in the books" as far as "everybody does it this way" so look at the original requirements.

42 high guard rail (to keep people from falling) is the norm. a 36" (+/1 2 inch) "handrail" where there is stars - doesn't seem to be needed along the dock though.

You need 50 lbf/linear foot sideways at the top of the rail (at the 42 inch), or a minimum of 200 lbs per post - and usually the posts are at 4 foot intervals (US) so the force per post limit becomes the requirement.

So build three of your posts. Anchor EXACTLY as you would propose in the dock - same hole, same depth, same rebar (if you choose rebar at all) and same edge distance from the edge of the dock.

Apply 200 lbf sideways to the top of the post. If deflection is within your limits on each of the test posts, accept the design. Now, if you build your test piece with the rails between the posts, the verticals will share the load, so the total load on the posts will be less than you 200 lb requirement. But I would check the T-connection and gluing anyway.

.

 

[racookpe1978]

By the way, do not be surprised if the existing concrete is the failure mode when tested.