# Bridge piers...what to use to make em



## Mike Reilley (Jan 2, 2008)

I've seen lots of bridge piers on these pages...but I don't recall seeing anything on how to form them. I've got this 15' long curved steel deck bridge to install. It will need anchorages at each end...and then three or four piers to support the steel towers. I'm leaning toward using concrete...but, are there other materials that I might consider as well?


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## Bruce Chandler (Jan 2, 2008)

I'm not real handy with concrete so I just cut up some Tufboard (a synthetic plastic wood), glued them together and sprayed some textured paint on them. They're light and easy to work with and come in all sorts of sizes - these are about 1 1/2" x by 3/4".












Garden Metal models makes some plastic piers that you could use as well, but they're a bit pricier.


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## lownote (Jan 3, 2008)

I've cast concrete piers using vinyl concrete patcher in a plywood mold. Painted chainsaw oil on the inside of the plywood mold as a mold release agent. Stuck some hardware cloth in the mold to act as rebar. It worked very well. I know some people have used foam insulation sheet. The 2 inch stuff is pretty strong and you can paint it or cover it with the concrete patcher












David Russell did a magnificent job on this:










He details the construction here:

http://www.largescalecentral.com/LS...p?id=10312


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## NTCGRR (Jan 2, 2008)

Mike 
I have 3 doublehigh GMM plastic piers I will part with , send me an PE if your interested.


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## aceinspp (Jan 2, 2008)

Aristo also has some prefab foam piers. Later RJD


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## Jerry Barnes (Jan 2, 2008)

Use some PT lumber for the inner structure, layer over some pink or blue foamboard. Score in some block shapes and paint it with latex.


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## Mike Reilley (Jan 2, 2008)

Posted By NTCGRR on 29 Jul 2009 12:07 PM 
Mike 
I have 3 doublehigh GMM plastic piers I will part with , send me an PE if your interested. 
Thanks Marty...but those aren't high enough. The bridge crosses a pond about 5' above it. Here's the site.










The bridge is a 180 degree turn going from the left side of the rock area....to the right side. It's a 5' 6" radius curve....and at the mid point, it's about 5' above the pond below.

The bridge anchorages/abutments will need to tie into the rock wall. I'm thinking of making a concrete form from some foam and pouring those. The bridge will be supported by steel towers...and those towers will need a foundation...a pier under each one...in the pond. I'm seeing good ideas here...using concrete again.


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## Russell Miller (Jan 3, 2008)

Use MagicSculpt Epoxy to form the piers. It will bond to the existing rock and the water will not effect it over time. You mix two equal parts together and then mold it like clay. It will harden up in about 2 hours. 
Russ


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## noelw (Jan 2, 2008)

*Mike.. What kind of uprights are u looking for? I put in two of them made of concrete ( 4 foot long ) and made Concrete bunkers for the end of my 10 foot bridge.. I made a casting box out of 1 X 4 and plywoods for the side with sheet rock screws to take off the sides when set up for a week. Is this the type of plier you looking for?If so they can be up to 8 foot if want with PVC conduit in it.. Re bar will rust and expand the concrete and in time crack it. course you will need a "A" frame to set them.. hahahha like i did.

Here are some photos I found.







* 
/1stclass/noelw/Hillsdale Bridge/SN851924.JPG

/1stclass/noelw/Hillsdale Bridge/SN852303.JPG


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## Mike Reilley (Jan 2, 2008)

The bridge legs are steel...hopefully like this photo.


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## tom h (Jan 2, 2008)

Mike that is one fine waterfall, got better pics of it?

tom h


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## Totalwrecker (Feb 26, 2009)

I'd pour on site.. 

Of course I'd use scale lumber to build the forms and modeling clay to seal around the bottom of the forms. 
I'd cast with CementAll, it doesn't shrink and is very strong. Mix some in a ziplock bag and cut off one corner about a 3/8's opening. 
I wouldn't worry about mold release, the boards break away and leave a nice surface behind... 
Squeeze the bag to fill a form, use a tamping stick to work out air bubbles and to flatten the top. 

If your forms are big enough you can pour your forms with the bridge in place and bring your pour up to the feets. The small bag opening should help you keep the cement where you want it, off the feets. 

Beautiful water works. 

John 

I've used the plastic bag trick to put cement in a horizontal hole.... about 20' off the ground, easy to carry and apply.


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## Mike Reilley (Jan 2, 2008)

It's hard to get a good photo of the waterfall...because it's below the front yard grade...and the house blocks a good photo. In the following photo,you can see the face of the wall. On the extreme right, you see the stacked rock next to the engineered wall block...that's where one of the bridge abutments has to go. 











Standing up top...and looking down...you see what the bridge piers needs to sit on. The "pond" down there is a dry rock sump with a pump box under the rock. There's no standing water to prevent mosquitos. 

There's about another foot of rock that needs to go in...to cover the overflow drain. Basically, the foundation for the bridge will be big gravel. Now that I look at this, it seems I might need to pour a "curb" on which to sit the piers...something big that won't move around, but can be covered by more gravel and rock.












The idea of building a mold from scale wood...and filling it with concrete is starting to sound good. Thanks John...


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