Thinking of doing a concrete pad for the mill.
What have other members done?
I'm thinking 6" with wire and fiber mix on a sand or stone base.
How large a pad you thinking Bruno?
If you walk all day on concrete, that can be hard on your knees.
6" with wire mesh should be sufficient Bruno. Probably the most important part is the side you will be driving up onto with your tractor loader and logs. You have the potential of putting some higher loading forces in that area but it should hold up as long as you maintain a good base under that approach where the tractor drives up on it.
Scraping out organic soils and backfilling with lifts of well compacted rock are probably more important than the concrete itself. A good slab can fail over a bad base just as surely as a bad slab.
If youll be putting a new building with few posts (wide span doorway) to hold up a substantial snowload then consider pouring the post footings independant of the slab, as in commercial construction where they sit on a chair. Load bearing walls are a spread load and posts are a point load. This is pretty easy to do with pallet racking mesh panels where the posts will go, then zip tie expansion material to the sides, stake some wood and pour the post footers first before the rest of the slab. Be sure to cut in control joints where you want it to crack. Extra mesh where you will drive a machine cant hurt either. If it isnt going to sit on a frost wall, be sure to haunch the perimeter. A floating slab should look like an upside down pizza crust. Concrete tries to curl upwards at the endges as it dries. Keep it wet for 3 days while curing.
The base beneath the slab doesnt have to be flat, it can be compacted with contours to achieve thicker concentration of concrete where needed. Say 4" slab with 7 or 8 inches where the loader drives or live deck feet will go. No matter what you do good base is the starting point for long lasting good results.
That said, if you dont really care how it looks or cracks and just want solid ground to stand on, pour away. My dad did a few no prep concrete driveway pads that have been just fine for nearly 40 yrs of trucks and equipment. Ironic.
I was planning to keep the operator walking off of the concrete as WDH mentioned walking on concrete all day is hard on the knees and feet
All of the stationary mills I've had experience with were put on piers first.
Everyone told me it was overkill but I had the fiber mixed into the concrete for my new mill building supports AND used wire in the forms. The fiber really only added about $10 / yard so it was well worth the extra insurance.
I doubt any of the folks who said it was overkill would volunteer to come out on a 98 degree, 95% humidity, day and dig out and repair a broken chunk of concrete had I not put the fiber in, pay now or pay later with projects like these I figure.
Quote from: Southside logger on October 15, 2018, 12:46:52 PM
Everyone told me it was overkill but I had the fiber mixed into the concrete for my new mill building supports AND used wire in the forms. The fiber really only added about $10 / yard so it was well worth the extra insurance.
I doubt any of the folks who said it was overkill would volunteer to come out on a 98 degree, 95% humidity, day and dig out and repair a broken chunk of concrete had I not put the fiber in, pay now or pay later with projects like these I figure.
That's the same reason why I put rebar and WWF in my drying shed floor this year as it will be subject to concentrated loads. Pay me now or pay me later I say. I placed continuous #5 rebar on 2" chairs around the entire slab perimeter and every 32" O.C. each way. then tied the WWF over it. My base was well compacted clay soil with a 3" to 4" thick leveling bed of compacted reclaimed concrete fines. I used a 4000 psi limestone mix in the 5 1/2" thick slab. That floor should hold up for a very long time.
Quote from: Bruno of NH on October 15, 2018, 11:35:01 AM
I was planning to keep the operator walking off of the concrete as WDH mentioned walking on concrete all day is hard on the knees and feet
It could be on the slab but put some anti-fatigue mats or a wood board walk to add a bit of spring, this will also keep you off the cold ground or concrete in the winter months and out of the wet other times.
Get it up in the air. All that stuff seem to sink. Or does the ground around it rise? :o
I will be using 4"-6" crushed concrete packed down, then adding some some crushed shaker fines to fill in the gaps between the 4 and 6, packed a bit more, then adding 2"-3" crushed, packed down and another top layer of fines again, packed till it wont compact anymore.
I'll then put some rr cross ties down under every bunk cross beam (15 ties total) with a 6" x 8" x 4" thick concrete pad on top of the ties. It'll get me off the ground about 16" counting my leveling feet, yet still low enough to be able to roll the logs that i cant lift with my tractor, onto the bunks.
Quote from: Jeff on October 15, 2018, 12:11:29 PMAll of the stationary mills I've had experience with were put on piers first.
I agree with Jeff that piers make more sense. You'll need a lot less concrete that way.
Bruno i don't know if you have a hydraulic log lifter on your mill . I just pored an 8x30 pad for my lt 70 and the lifter supports were above the ground next to the pad. The first big log i tried slid the mill sideways . since then i have installed anchor bolts and supported my log lifter base legs.
WDH is right about walking on concrete but i don't have to.
For me here when it is wet i cant saw . now i don't have to constantly adjust my out riggers and i can keep things clean under the mill.
Next get your self a back pack leaf blower with some power and you won't regret it.
I don't know about you but I will take walking on nice smooth concrete all day as apposed to walking an hour on nice soft freshly plowed soil any time . and if the concrete has heat in the winter all the better. put heat tubes under it even if it is outside . you will like that hooked up to an old wood burner
My mill pad is concrete 22 x 32.
Why I like it:
Nice stable flat work area.
I can park the skid steer on it.
I offbear from the mill onto the skid steer.
Easy to clean. I use a leaf blower.
The only problem is that it is hard on my feet.
Sometimes I spread sawdust onto my walking area. This helps a lot.
Jon
When milling at home, my mill is set up on a concrete pad, under cover. I much prefer milling on concrete. Easier to setup, much more stable, much easier to clean, less concerns about rain/snow conditions. My TK B-20 has an operator's station and there I have a stool, on a 4x6 rubber horse stall mat. Any walking I do along the mill, is on sawdust after a few cuts, so I seldom walk directly on the concrete.
I'm with Mike- your base is everything. Especially with the cost if redi-mix, I want to use enough mud, but not because I did a sloppy job on the base. If you want to increase the strength of the slab, you have to use bar. Mesh helps with small cracks, but it doesn't actually increase strength.
Quote from: barbender on October 17, 2018, 12:16:10 PM
If you want to increase the strength of the slab, you have to use bar. Mesh helps with small cracks, but it doesn't actually increase strength.
That's what I've always heard too. Also that the embedded fiberglass only helps with small cracking during the initial cure and that once the concrete has set it provides no strength.
Alan
If it is going to uncovered, in the elements for a while, you may want to look into having air entrained concrete. It helps with freeze-thaw, and scaling from de-icing chemicals. Don't know where you are located at, just some food for thought. And cudos for the thought process of over building, these situations are the definition of "better to have and not need, than to need and not have".
If there is a rock crushing plant anywhere close to you, they should have some used conver belting that you can put where you walk at very little to maybe no cost. I have a couple of pieces where I normally stand. If you don't let the saw dust get too big of a jump on you, the concrete cleans up easy. Blow it off every evening and your done. Banjo
I backfilled with true southern clay which sets up hard as a rock and became like concrete. After awhile, I was feeling it through my knees, and then put down some of the interlocking rubber flooring pads like used in weights rooms. These work great and are very soft and cover the clay. My daughter bought them at a salvage store.
Ill second that hard as a rock notion. A lot of the clay fill that was brought here slopped out of the bed like pancake batter, it was dug from below water table to backfill with shotrock base for a building.
I dozed a patch of hardened stuff to flatten a few days ago and it is very similar to scraping concrete. With the front idlers in the air i could only take off an inch. Unbelievable stuff. I fill puddles by thinking of it as mortar.. Just shovel it in, churn it up to batter and let it self level. Will turn to concrete on its own.
Roger that on the clay. That's what's here. Some areas are about 1/2 clay and 1/2 smooth gravel. Called bank gravel. Packs up hard. Makes a great road bed. Only time you can grade it is during spring thaw.
Not sure if they have clay up there in the gritless north land.
Sounds to me the best ideas thrown out here are piers for the mill and a boardwalk to walk on. It's pretty easy to throw together a board walk and it's good way to use up some low grade lumber.
my clay is same way but during the sporing and fall it is nothing but mush under whatever is on top of it. if ti wasn't for the landscaping fabric I put under the gravel, the gravel would be all gone.
Yeah, standing water will fully re-slake hardened clay then rut up and just get worse. Crown and fast runoff are super critical. It takes a LOT of big rock to replace that geotextile. Id say 12" of big then medium then fine rock compares to one layer of geotextile with 4" of 3minus on it. I have areas where the fabric is showing through that are still great. It seems expensive upfront but its cheaper than migrating rock every year.