pouring sidewalks; reinforcement?

[rogdan]

Its been years since I helped anyone with any concrete work and I keep getting conflicting advice. I am building 3' and 4' wide side walks framed with 2x4 lumber and don't know how to reinforce the concrete. Some say to use reinforcement rod but not what size or how to space it, some say the reinforcing wire or just any old fence wire will do and some even say to not worry about reinforcing concrete for just side walks. I am mixing the concrete myself with a mixer to work around my free time and expect to mix 3-2-1 stone, sand and portland.
Any advice would be greatly appreciated, I am in zone agricultural 5-6 if that has any relevance.

 

[Jarrett]

For a sidewalk I would use reinforcing wire. That should suffice. Down here, that's all that's used in slabs, even for buildings, except maybe for commercial buildings.

 

[Highbeam]

In western washington we use no reinforcement in the sidewalks. 4" of concrete above 4" of compacted 5/8- crushed rock.

3-2-1 is a great method and one they taught us in school to use when you have just the ingredients.

 

[Dhill]

Reinforcing the concrete is not necessary, but it's a good idea. For that application, I would recommend putting some kind of mesh wire (chicken wire would work well). Re-bar I think would be over kill. The idea is that you don't want the walkway to crack, and the more stuff you have in there to solidify the pour, the better. You may be able to find scrap wire pieces laying around to use. When I poured the slab for my shed, I used some old field fence pieces and mesh wire. Just be careful to not let the wire stick above the finished surface, and be sure to have something beneath it to keep it from sinking to the bottom when you pour the mix. Ideally, the reinforcing material should be suspended in the middle of the concrete. Of course, there are other considerations that effect the need for reinforcement such as ground shifting and moisture content of the soil. Good luck.

 

[EddieWalker]

Here in East Texas, the new subdivisions don't use anything in there sidewalks. Just a good base adn 2x4's for framing.

On my own projects, I like to put two sticks of 3/8 rebar in there. Nothing fancy, just someithing to help hold it all together.

Wire is a pain to deal with on pads. For a sidewalk, it would really add allot of extra work to a job with minimal returns. Another thing to remember about wire is that it has to be in the middle of the pour to do anything. Most of the time, part of it is on the bottom of the pour. Sometimes almost all of it is!!!

I read an article about using wire mesh in pads. They did some sample pours, then went back after they had dried to test for strength and wire location. In the places that the wire was in the middle of the pour, it was stronger than rebar. I forget what sized rebar they were talking about or the spacing. But what was really interesting is that in every case, part of the wire was at the bottom of the pour. And this was on a special test pour to do it right. The pros can't keep the wire in the center of a pour, and neither can I.

Eddie

 

[scott_vt]

Afternoon Rogdan,
In the limited amount of concrete work that I have done I have used the wire mesh with very good results. The drawback as Eddie has just mentioned is that its a pain to work with. What I bought came in 6' wide rolls and 50 or 100' long. Not easy to manuever that stuff around But the results were good.

 

[RobertN]

The pros can't keep the wire in the center of a pour, and neither can I.
Eddie

That's where you use the little concrete blocks with the tie wire in them. The little concrete clock spaces the rebar or mesh about 1.5 above the base level. They're another step and expense though.

Out here, I've seen people use fiber reinforcement. It looks like batt's of fiberglass insulation that they throw in the mix. When the concrete is done, it looks a little "hairy" on the surface, although that wear off quickly. I have no idea how it compares to rebar or wire mesh though.

 

[rogdan]

I think I will look for some old fencing around the farm to use, might as well save a few bucks and help the clean up. Thanks for the responses

 

[RobJ]

That's where you use the little concrete blocks with the tie wire in them. The little concrete clock spaces the rebar or mesh about 1.5 above the base level. They're another step and expense though.

They are called chairs, some in metal and some in plastic, different shapes and sizes.

Also if you use a cement kumalong it has a hook on the back to be used to pull the wire back to the middle.

Oh and if you use the rolled wire mesh, be sure you TRUST the person on the free end. Trust as in when you ask them to step on the end that they will STAY there(and are heavy enough!!). I think the end will spring back to the roll at mach 2.3.

 

[EddieWalker]

The chairs are for rebar. They used to be pretty common in the cemtent blocks, but now it seems all I see are the little plastic pyramid shaped ones. They are dirt cheap and easy to use.

If you put them on wire mesh, they will hold the wire up in that location, but the wire will still bend. I guess if you used enough of them it would work, but I've never seen it done, nor do I know if too many chairs will affect the integrity of the pour.

For a sidewalk, keep it simple and either use nothing, or just a few stick of rebar. No need to make it any harder than you have to.

Eddie

 

[Egon]

Ahh - just add an extra shovel of portland for each mix and put a cross groove every 5 feet. tool pic. attached.

 

[EddieWalker]

Sounds like a commercial.

Interesting that you never mentioned rebar or site prep. And by the time I got to the end of it, I was expecting the sales pitch for what you are selling.

Anybody want to guess what company the poster works for? LOL

Eddie

 

[JB4310]

Oh and if you use the rolled wire mesh, be sure you TRUST the person on the free end. Trust as in when you ask them to step on the end that they will STAY there(and are heavy enough!!). I think the end will spring back to the roll at mach 2.3.

That's what I wanted to say, especially the heavy 6x6x6ga, that stuff is scary in the hands of the inexperienced. They do make flats, you can cut the width you need would be easier to work with.

Steel mesh is standard practice around here for municipal walks, residential and commercial slabs. As far as setting up in the middle of the slab, that's the text book install but often doesn't get done, regardless of that wire sitting on the bottom, it still reinforces and stabilizes, makes it a real bear to demo as some concrete always gets under it. Easier to demo concrete with bar in it than mesh IMO.

The OP is only dong 3-4 ft wide walks, I'd still run some 3/8 (#3) bar or the mesh, small amount of extra work for a more permanent job.

.

 

[EddieWalker]

Sounds like a commercial.

Interesting that you never mentioned rebar or site prep. And by the time I got to the end of it, I was expecting the sales pitch for what you are selling.

Anybody want to guess what company the poster works for? LOL

Eddie

OK, where did the post go where the so called concrete expert chimed in and ended his post with a recomendationan link to the best product in the world?

Guess it got deleted. LOL

Eddie

 

[JB4310]

OK, where did the post go where the so called concrete expert chimed in and ended his post with a recomendationan link to the best product in the world?

Guess it got deleted. LOL

Eddie

Yeah I figured there must of been a post removed when I read your previous reply.

Either the poster was shammed into removing or the moderators did it, most likely the latter.

Enterprising businesses find our discussions with key word searches and find a quick and easy way to get a plug in for their product. I'm always suspect when I see someone just joined TBN to recommend a product.

 

[czechsonofagun]

I am a cheap skate and used in sidewalks parts of an old no climb wire fencing. Pretty much the same as mesh.

And to support it - I saw concrete crew use frozen chunks of dirt under their rebar! That quite amazed me, the American way of pours

 

[Topstrap]

The couple of contractors I dig for seldom use rebar or wire for sidewalks. They all do put a stone base under the concrete, Some say it's to allow drainage and others use to to get a nice level area for the concrete. For footers most do use 2 or 3 rows of rebar and we always dig a 24" footer and usually pour at least 10" of concrete for the footer. For driveways some use wire, some rebar and others use just fiber in the mix. My shop floor and my front porch both have fiber in it and not one single crack anywhere. I did use a good base and the garage floor was well packed before pouring and even has a 3' diameter hole 6' deep that I set a JIB crane in and it's not even cracked around it.

I think a lot has to do with base prep as to how good the concrete holds up. As they say, concrete will crack but you need to control where you want it to crack at. Homeowners always are anxious to get their driveway and sidewalks poured as soon as the home is done but the settling is not done and usually they end up cracking and or tilting. Also spending a lil bit more and making a 5 1/2" pour instead of a 3 1/2" or 4" pour will help too. Keeping it damp as long as possible while it cures will also help.

Funny things you dig up sometimes when you break up an old driveway, sidewalk or steps. It amazing how many car parts, scrap steel, bed springs and frames, tractor parts, discarded things from a railroad and items I've never seen before end up in concrete. I've not found any guns yet but I'm sure only a matter of time till one shows up.

Topstrap

 

[Guywire]

Watch out for Jimmy Hoffa...

 

[Cat_Driver]

Ask the batch plant to add some either stainless steel fibers or fiberglass fibers.

 

[Matt_Jr]

I watched a 200 yard pour at work for our rear parking lot, and they put mesh down on top of bricks. The concrete is 3 feet in some places. When some guys do small jobs they just pour the concrete, then push mesh or rebar in before finishing.