Building The Outdoor Stairs

[ArtMech]

Beautiful job on forming and reinforcing your stairs. Hope everything turns out good.

Here are some things to consider when you are ready to pour the upcoming supporting deck beam.
1) Be sure to include aggregate (different sizes is best).
2) Mix as stiff (less water) as you can (add water a cup at a time near the end of the mixing process). The optimum ratio is 0.4/1.0 water/cement
3) The wetter you can keep it during the curing the stronger it will be. This is a cement hydration process, it is not "drying".
4) There is a thing such as to much cement in a batch and will actually make the finished concrete weaker.
5) Typically, it is expected that a concrete mix will reach 50% of its design strength in 3 days, 75% in 7 days, and 98+% at 28 days.

I know you were trying to mix thin to get the concrete to flow in the forms but a "Hand Held Concrete Electric Vibrator" such as this one on Amazon
(Amazon.com)
this is just an example because I don't know what your electrical requirements are.

This vibrator will make a very stiff concrete mix flow very good and fill your forms without a lot of air pockets.

Good luck

It's really nice you described some points on my future works.

1/ I don't know the meaning of expression "to include aggregate".
2/ I've already learned a good lesson on the water proportion in this thread. I'll have to merge fresh concrete with the existing one. In this case I know I will have to moisten the existing one well.
3/ It's clear.
4/ I always knew the proportion of sand and cement 4x1 has to be immutable.

As a vibrator I usually use a bench grinder. I put a plank on the edges of the formwork or on the sticking out rebar, switch it on and let it do the job.
Here in EU we have 220 V, 50 Hz of AC.

 

[950deerehunter]

It's really nice you described some points on my future works.

1/ I don't know the meaning of expression "to include aggregate".
2/ I've already learned a good lesson on the water proportion in this thread. I'll have to merge fresh concrete with the existing one. In this case I know I will have to moisten the existing one well.
3/ It's clear.
4/ I always knew the proportion of sand and cement 4x1 has to be immutable.

As a vibrator I usually use a bench grinder. I put a plank on the edges of the formwork or on the sticking out rebar, switch it on and let it do the job.
Here in EU we have 220 V, 50 Hz of AC.

In concrete large aggregate is small rock or stone (1cm-3cm or even larger). The best rocks/stones are round and smooth which lends itself to less large air pockets. Be sure it is washed for good adhesion. Sand is a Fine aggregate. The ratio works good at 3parts sand to 4 parts stone.
Mortar is the same without the rock/stone.

 

[ArtMech]

In concrete large aggregate is small rock or stone (1cm-3cm or even larger). The best rocks/stones are round and smooth which lends itself to less large air pockets. Be sure it is washed for good adhesion. Sand is a Fine aggregate. The ratio works good at 3parts sand to 4 parts stone.
Mortar is the same without the rock/stone.

Thank you for explanation.
In my posts I used an expression "Concrete Sand", that's how we call it. It means the sand already includes small stones. I have bought it from the sand quarry where they make it. They sell the sifted and washed sand with up to 15 mm stones left ready for mixture.

 

[ArtMech]

Here is a just created video about how I had to fix my concrete mixing machine before starting all works. It was broken its LH side axle.

 

[ArtMech]

Ok, lets go further with the project. Before that I have something to ask.
I'd be much appretiated if someone might answer a question.
How deep should the rebar be sunk in the concrete as shown in a picture below? I mean distances "x" and "y"?
Thank you in advance.

 

[EddieWalker]

I drill about 4 inches into existing concrete, then I vacuum out the hole, fill it with construction adhesive rated for concrete and metal, then I put the rebar in, and turn it while its in the hole to get maximum contact with the adhesive and concrete.

 

[ArtMech]

I drill about 4 inches into existing concrete, then I vacuum out the hole, fill it with construction adhesive rated for concrete and metal, then I put the rebar in, and turn it while its in the hole to get maximum contact with the adhesive and concrete.

I'm sorry, my question was probably incorrect. I will need to make that beam of concrete. It doesn't exist yet. But before that I need to know, how should I place the rebar in the formwork correctly.

 

[fishdrivel]

Ok, lets go further with the project. Before that I have something to ask.
It'd be much appreciated if someone might answer a question.
How deep should the rebar be sunk in the concrete as shown in a picture below? I mean distances "x" and "y"?
Thank you in advance.

View attachment 745968

Minimum cover for concrete is 1.5 inches. That is minimum - more is better. Your decision is complicated by the size of this beam. I would recommend 4cm for ""x" and "y"

 

[ArtMech]

The current look of the stairs.

 

[ArtMech]

Minimum cover for concrete is 1.5 inches. That is minimum - more is better. Your decision is complicated by the size of this beam. I would recommend 4cm for ""x" and "y"

Very good. I thought so, but was not sure. I was prepared it'll be between 4 an 5 cm. Many thanks.