Building The Outdoor Stairs

[ROUSTABOUT]

When concrete is mixed at a ready mix plant, there are a lot of additives that can be added. If you did all the mix yourself, then it does not matter, you cannot do that.
Air-entrained concrete contains billions of microscopic air cells per cubic foot. These air pockets relieve internal pressure on the concrete by providing tiny chambers for water to expand into when it freezes. Here, most concrete poured outdoors for curbs, sidewalks etc used this to resist weathering.
But is must be done at the mix plant and can be done if you order concrete.

If you mixed all your concrete, then you don't have that option. Mixing concrete in a bag or wheel barrow is not a lot of fun, but is a lot of work. I have a mixer that I use to ix 3- 80lb bags at a time. Helps a lot, but since I am older, don't really plan of lifting those bags again. Hopefully. Oh, buy the way, that definition above is from the American Concrete Manufactures Association, not my definition. Most of all I know about concrete comes from working for a large ready mix plant here. I drove a mixer truck for many years and have seen thousands of yards of mix poured, with many different additives. Best wishes. Your project looks good.

I want some 6 sack mix, type 3, with hot water.

 

[ArtMech]

Some pics to observe a concrete quality visually. I tried to hit it with a hammer many times in different places. Looks like it's not brittle or soft. I also did not find any cracks during solidification, except for those left over due to the uneven distribution of the concrete (not many, but my mistake).

 

[ArtMech]

I've made 5 supports to be sunk in the concrete of a new beam under each column.

 

[ArtMech]

To release the download of a balcony and upper wooden beam I used a tractor's forklift and a wooden lifting post. Then placed 3 wooden support posts.

Pic with a forklift released and lifting post removed.

Pics of how the columns look like while released.

And how a balcony from under the upper wooden beam are now supported by those 3 wooden support posts.

 

[ArtMech]

Now I can cut a lower rotten beam into pieces and remove them.

 

[ArtMech]

The lower beam pieces from under the columns had to be removed in the other way - while slightly lifting the columns (within the gap provided by the support posts) using a screw jack.

 

[ArtMech]

After that it's time to place 5 welded supports under the columns (shown in the post #63).

And to continue welding of rebar for the last 2 upper steps and the concrete beam.

 

[2manyrocks]

I had to rebuild part of a foundation under my barn some years ago. There was no way I could come up with enough jacks to lift the entire section of barn wall. Instead, I used posts set at an angle with wedges as described in this article in Fine Homebuilding called "Restoring a Porch" by Roy F. Cole, Jr. Porches, Decks and Outbuildings

 

[ArtMech]

I welded up those 5 supports under the wooden columns with the continuous rebar. All this together with the concrete will form a whole lower beam structure and will be connected to the stairs. I am still going to weld the long nuts to the rebar so that I can cover the finished concrete beam with tin from above and screw them on in those nuts. And that will be all the welding work on the rebar.
Now I am trying to find two 6 m long boards for the beam side formwork. One must be 17 cm wide, the other 22 cm. The 3 bottom boards - no problem.

 

[2manyrocks]

I just replaced a rotted wooden sill beam that was in contact with a concrete porch landing. Apparently, concrete holds moisture like a sponge.

One construction detail that you may want to consider is maintaining an air space between your wood and your concrete. This isn't what you would be using, but might give you an idea of how to separate a wooden post from direct contact with concrete. Simpson Strong-Tie ABA ZMAX Galvanized Adjustable Standoff Post Base for 4x4 Actual Rough Lumber ABA44RZ

In your case, I could see fabricating a metal plate to separate the two.

You also want to separate any other areas where concrete meets wood or at least use galvanized flashing.