Re-Decking a Bridge

[wvpolekat]

I am going to be helping a friend redeck a bridge. Wish I had taken some pics, but let me describe it for now.

Current bridge is approx 20 feet long going over a small creek. Bridge is supported by 4 12" steel pipes going in the ground and then 3 12" steel pipes running the length.

Originally, the bridge had a wood deck. Sometime in the last 10 years, the previous owner put approx 3" of concrete on top of the wood deck. The concrete has wire mesh for reinforcement.

What has happened is that the wood has rotted out under the concrete and a large hole has formed, I assume because of lack of support.

The current plan is to rip up the concrete and rotten wood and redeck with new oak from a local mill.

The question is mostly regarding removing the concrete.

We have 2 kubotas to use, my B7500 and another B or BX with a hoe.

Using the current hole that is about 1 foot in diameter, is busting the concrete up with the hoe reasonable?

Renting something like a jackhammer is really not in the budget, and there is no place within an hour to do it anyhow.

 

[beenthere]

No suggestions, as the description didn't leave enough knowledge of what you are faced with to comment.
Wish you luck.

Hopefully others have a better take on the details than what was provided.

Best I could recommend would be to lift it off.

 

[wvpolekat]

No suggestions, as the description didn't leave enough knowledge of what you are faced with to comment.
Wish you luck.

Hopefully others have a better take on the details than what was provided.

Best I could recommend would be to lift it off.

Lift it off??! How do you propose we lift a 3" thick slab of concrete that is 10 feet wide and 20-30 feet long?

 

[EddieWalker]

Do you have a rotary hammer?

I've taken out pads that size behind houses that I couldn't get anything big into to haul it off, so I broke it into small pieces. My SDS Max Rotary Hammer is also a small jackhammer. It does an amazing job of breaking up concrete pads. Depending on what size the mess is, you can cut it with wire cutters, a grinder or a torch. My guess is that you can just break off the concrete from the wire and let the concrete fall into the creek bottom to act at rip rap. Might be nice for the approach to the bridge too!!!!

The hoe buckets should hanldle this easily. It's just hard to control the size of what you break off, and not damaging anything else. Until you try it, you'll never know if the results are satisfactory. If I didn't have a generator or a way to power the rotary hammer, I'd try with the bakhoe.

Have you priced what oak will cost to do the job? I would go with PT 2x8's.

My thought is the concrete held water under it, and on top of the wood. Since it would be wet for extended perioud of time, it rotted out. Once it started, the process just speeds up and gets worse.

PT wood will last decades if it's allowed to dry out.

I have oak on my land and if left out, it rots fairly quickly. I would never use it for anything exterior. I also know that there are differnt types of oak, so maybe you are buying something that I'm not familiar with.

Eddie

 

[dstig1]

Lift it off??! How do you propose we lift a 3" thick slab of concrete that is 10 feet wide and 20-30 feet long?

2 guys. Lift with your legs, not your back.:laughing:

The new decking will be White Oak, not red, I hope. WO has natural rot resistance, RO does not.

Edit: Or PT as Eddie posted (same time I was writing...)

 

[gwjd]

this adds some more work but a good coat of deck stain or selant on all 4 sides befor it is put on the brige may not be a bad idea

 

[wvpolekat]

I do believe it is white oak. It is the standard fare for bridge decking around here.

Eddie, you are correct that we can just let things fall. We can also get under there with a tractor if needed.

I am considering making up or getting something pointy to mount in my 2" receiver that is part of my plow project. Basically, it is a 2" receiver that is mounted in a 3x5 piece of steel that mounts in place of the bucket. But, I worry that would not have enough reach and would be hard on the loader.

 

[beenthere]

Lift it off??! How do you propose we lift a 3" thick slab of concrete that is 10 feet wide and 20-30 feet long?

That is as good as I could come up with, given the little bit of information provided.
Note that you didn't offer how wide the bridge was, nor whether it was a foot bridge or one to carry traffic (truck, car, tractor, lawn mowers, or whatever).

Give more information, and maybe the answers will be more in line with what you need to do. We are not the ones with the problem.

 

[wvpolekat]

That is as good as I could come up with, given the little bit of information provided.
Note that you didn't offer how wide the bridge was, nor whether it was a foot bridge or one to carry traffic (truck, car, tractor, lawn mowers, or whatever).

Give more information, and maybe the answers will be more in line with what you need to do. We are not the ones with the problem.

It's a bridge being supported with 4 12" steel pipes with 3 12" steel pipes running it's length and has a 3" concrete deck over wood. Does it sound like a foot bridge?

 

[radioman]

I really don't think you will be able to crack and pull out sections of concrete with mesh on it with an BX. The curling power is not enough. A B- maybe. It looks like you are going to be doing it with a sledge hammer and alot of elbow grease if your budget is pretty small. Once you get the pieces broken up, the BX hoe can lift the concrete sections once its loose.

 

[Western]

Electric jack hammer may be cheaper if you have excess to a generator.

You may also be able to use either the BH or a couple of sledge hammers to bust out 3' widths then try ripping it out with a heavy chain.

Without a jack hammer it may have to be done with "blood, sweat and tears"

Good luck with it, I suspect it will be tougher than an ex-wife without big tools.

 

[TRR]

Use a gas powered concrete saw and cut it into managable pieces.

 

[mikefromnh]

Use a gas powered concrete saw and cut it into managable pieces.

And we have a winner! Just what I was going to say

 

[wvpolekat]

I will have to check on how far to electricity. If the neighbor nearest is friendly, that would be less than 100 feet. Electric jackhammer sounds promising.

Beyond that, gas powered saw may be the winner.

I do also have a rotary hammer that I loaned out about a year ago, will have to see if I can track it down.

Using the jackhammer on the bridge you are standing on could be an adventure as well.

Need to do some calculations on what size we need to break the concrete up into so we can handle them if we are not just going to drop them into the creek.

 

[boggen]

1 foot by 1 foot sections of 3" concrete or smaller. if your in shape. can be handled. though recommend 1 foot by 1/2 foot by 3" if you are going to be at it all day long manual lifting the stuff up and out.

you will want some good size strong prybars. say 4 feet to 6 feet long. also some wedges and sledge hammer.

having a good set of wire cutters and pending on mesh perhaps a grinder to get through some of the wire mesh.

an eletrical jack hammer weight is around i would say 50 to 70 lbs. and some can be plugged into standard 110 outlets like most houses have.

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being that this is actually on a bridge. i would say go for the gas powered concrete saw.

trick is to create a grid out of saw cuts. to create your "breaking spots" of the concrete. for example make yourself 1 foot by 1foot grid. go along the width of the bridge and cut a strip every 1 foot. then do same thing for the length. ((when cutting)) don't go all the way through the concrete. but say half way through it or less

when ya done with the saw, get some wedges. ((like splitting firewood wedges)) and a sledge hammer. and you should be able to just tap the concrete sections out. and use wedges were needed for the tougher spots. some times pry bars are needed.

since you have a backhoe. once you get cuts made. you might be able to just drop the bucket down on the pieces and nock them off. or perhaps lift up corner pieces right into the bucket.

the problem will be the wire mesh. you will most likely find some areas are low in the concrete while other spots are high in the concrete. and pending on size of wire mesh, you may need a good pair of wire cutters or bolt cutters to a grinder even. so chunks of concrete break into smaller chunks and don't get hung onto each other via the wire mesh.

being ya have a backhoe. having a few good log chains. and pulling out chunks by the wire mesh can work nicely to.

======================
due to wire mesh being in the concrete. i honestly do not suggest trying to use it any place. those wires can be like stepping straight down on a nail. and when in water even harder to see.

 

[Western]

I have an electric Jack hammer and a Sthil concrete saw (hand held). I would rather argue with the jack hammer all day then cut that much with the hand saw. Not to mention the dust if dry cutting and the blades will cost ya big time. They do have a water line attachment, but you may not have water available.

My hammer weighs like 80# which is all you feel when you lift. It lacks the power of our pneumatic hammer but at 110# that dude is a workout.

2 young fellers and the hammer, should have it broke up in less than a good day.

 

[EddieWalker]

Good luck finding two young guys who want to work, and do so all day long!!!!

Eddie

 

[mjncad]

Go with the gas saw, preferably a walk behind. The electric jackhammers work well; but it will beat you up worse than the saw will.

 

[MarkV]

I would not give up on the backhoe yet. I have torn out a slab with a Kubota B21. With little support left under the concrete you may be able to break it into reasonable sections. The wire in the concrete is what is hard to deal with.

MarkV

 

[wvpolekat]

Since we don't have a saw etc... and will have to rent it, I wonder about a mini excavator with a breaker. Or even renting a full size TLB, it would have enough power to just rip the concrete up. Heck, a good forklift could start at the approach and get the forks under it from the end and just keep picking up it till it breaks. A mini ex may well have enough power to break the concrete up without a hammer as well.

We can get into the creek bed on one side of the bridge with a tractor/atv/excavator. It may be possible to just find a way to knock it all down into the creek then work with it there. My worry is being ON the bridge while tearing the deck up. Seems like a Darwin moment waiting to happen.

The creek is less than 6 feet below, so we can work from top or bottom.

Cutting the bridge up into 1' by 1' sections would be A LOT of cutting.

The mesh is not proper mesh, more like chicken wire.