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Pouring concrete defects at the base of the column

Pouring concrete defects at the base of the column

Pouring concrete defects at the base of the column

(OP)
Hello, i have almost completed the rehabilitation and extension to 1st floor of my house.
Summarize: Old brick house (ground floor) with simple concrete foundation (not reinforced) but in good shape. The solution was to keep only externals full brick walls (small type, capacity bearing),to reinforce them with metallic net of 10x10cm(6mm diam) and to shotcrete(to pomp wet concrete c20/25) on the internal part (the net was clipped on the wall before the shotcrete). The extension to 1st floor was made by creating a new continous foundation marginal to the existing one and monolithized with chemical anchors (to the existing foundation), from where the new frames started (columns and beams). So the new frame structure is at the interior of the old bricks wall. The new slab between ground floor and 1st floor is siting also on the old wall. For the 1st floor i used new load bearing bricks and installed it in "streps" (so the bricks wall will also be responsible in case of an earthquake to take over efforts). The columns are 40x25cm, C20/25 concrete, 10 vertical bars of 14mm, big stirrups every 10cm, small stirrups and clips every 20cm.
Problem: At the base of the columns i had some small pouring defects (segregations), but for the central column at the ground floor I had to repair a big section of it pouring Sika grout (it is specified in the technical guide it joins with the existing concrete without joints). These issues were discussed with the responsible engineer, the structurist and expert, but still not sure is ok, also i made some indestructible tests with the sclerometer using the combined method and the repairs are on the concrete class ...
Question:: What can happen in case of earthquake with the grout i poured? Can it be shaked and throwed out? Can crack?
I attach photo with the initial problem, after i removed the bad concrete, and with the repair.

RE: Pouring concrete defects at the base of the column

That's some of the worst concrete I've ever seen... I'd likely reshore the structure, remove it and do it properly...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Pouring concrete defects at the base of the column

Agree with dik. Next time, make your forms so they don't leak, and do a good job of consolidating the concrete by vibration.

RE: Pouring concrete defects at the base of the column

(OP)
Thanks for the reply, the pics below are after i removed the segregation. I add the pic to see how it looked în the begining.
Still, how can i reshore the structure as it is already done, including the slabs on the ground floor and on the 1st floor?
Should i break the column and pour it again?
What can happen during an earthquake?

RE: Pouring concrete defects at the base of the column

Difficult to understand your project. Do you have drawings? Use the "image" option to post the pictures instead of as an attachment.

RE: Pouring concrete defects at the base of the column

(OP)



RE: Pouring concrete defects at the base of the column

(OP)
This is after repairing with Sika grout.

"bimr" i can't add here all the drawings.
The question is what can happen during an earthquake with this repair? Can it crack?
Still i understood that this type of grout is used for such repairs, even bigger than a house, like for bridges, water towers etc..

RE: Pouring concrete defects at the base of the column

Why so much rebar? Can you get by with 4 bars vertical (in the corners)? What is the load? With 4 small bars, you could likely accommodate 100K load... Congestion is part of the problem... Your concrete strength (from the colour) looks over 4Ksi stuff... Vibration and 4" slump should fill 'er out nicely.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Pouring concrete defects at the base of the column

(OP)
Yes, you are right, the reinforce congestion is the problem.. I don't understand why the structural engineer indicate so many rebars. Still the rule for the concrete to fit between the bars is respected as it was 16 mm diam max, but în reallife we can see it was bad. The loads are for a normal house în a semi seismic area(Bucharest România), where also the snow Loaf is taken în consideration.
Still i didn't received the answers. What can happen during an earthquake? I used repair materials that were recomended by the expert and the structural engineer and after the schleromether tests used în the combine method, the results of the repairs are good(în the concrete class of 20/25).

RE: Pouring concrete defects at the base of the column

The answer to " what can happen?" is your building might completely collapse. Rip out all the defective material and replace with hi quality concrete , placed by personnel who know what they are doings

RE: Pouring concrete defects at the base of the column

Quote (Still the rule for the concrete to fit between the bars is respected)


You can tell how well that worked, in looking at the pictures...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

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