what can i do for that building

[swelm]

hi everybody

my friend send me that pic and said to me what can i do

if you check the pic you will find 2 column is not verticaly

i will not take decision until i see all comments


best regards

 

[hokie66]

Swelm,

I don't know where this is, but looks like what these fellows have built so far is very shoddy. The columns being out of plumb is probably not the worst thing they have done. If you look closely at some of the columns at the bottom of the floor, the columns have been cast above the floor soffit. Therefore, there is probably a punching shear issue at these locations. I know standards differ widely, but you asked, so my answer would be to reject the structure as it stands.

 

[msquared48]

Looks like the columns are bent at the break in the pour - rock pockets abound. P-Delta definitely. And there are workers actually taking a break under this thing?

My next question is "What don't I see here that would scare the ^%@) out of me too?"

Mike McCann
McCann Engineering

 

[msquared48]

Two options here:

1. A D10, or

2. C4

I bet the break in the pours of the lower columns happened at column splice locations too.

I also see bent rebar in the column vertical steel yet to be tied. At least I hope they were to be tied.

Mike McCann
McCann Engineering

 

[IFRs]

This looks to be in a part of the world where building codes are not read or enforced and local materials and labor are used. My guess is that there is not enough money available to "do it right". What type of structure is this to be? A one-story farmer's market? An apartment complex? A theater or government building? Are there any wind, water or seismic loads expected? What is the expected lifetime of the structure? Will all the colums bays be filled with brick?

 

[Zambo]

Looks like Africa? North Africa? Is it Libya?

The date of the picture is 29 September, so I guess the house is finished and all beautiful now.

 

[concretemasonry]

I assume the existing probably will not be removed, so like many buidings of this type, the masonry infill actually becomes very important structurally. Unfortunately, most U.S. based research and assumptions are not accurate enough to provide a good analysis for this type of structure. - Mainly because of interest and lack of exposure.

I assume the exterior walls will have some infill. The amount of interior infill is unknown. The infill panels are very important and possibly more important than the frame depending on the column/slab connection/construction.

For future suggestions, form and pour each column to the full story height in one pour to insure continuity. This eliminates the problem of making the upper portion aligned axially and vertical with the lower portion.

If reasonable quality block are available, consider using them since you have the opportunity to reinforce lightly (4' O.C) and use an intemediate bond beam. If this is actually in Africa (I could not recognize the license plate on the car), even the common 6" block will be better than the brick shown in the photo. Some parts of Africa have very good hollow concrete products. In any location, hollow block will be a better choice than the local brick.

The brick shown in the lower left of the photo, appear to have the proportions to use as a double thicknes wall that should be cross bonded every 3 or 4 courses. Unfortunately it may be difficult to find materials for increasing the panel strength. I imagine some sort of plaster will be applied to the exterior.

Just some thoughts based on very little information, but some experience on similar structures.

Dick

 

[Zambo]

concretemasonary,

I like the way your comments address the local conditions (I agree it cannot be confirmed as Africa until the OP gets back to us).

When working with "local standard" building practices I always like to stress that materials are expensive and good detailing is usually relatively cheap. Perhaps someone should write a simple, illustrated book showing cheap, easy, good connections etc.

As for hollow blocks, as these contain cement and crushed aggregates they are usually more expensive than clay bricks.

 

[concretemasonry]

Zambo -

Internationally, clay brick and concrete masonry units are not comparable in terms of structural or cost cost. That is the reason for the increased use of concrete masonry.

Most clay brick (many are "mud brick")are cheap and the quality is limited by the type of clay that is locally available. For most of the world, good clay is not locally available and the cost of firing the clay properly does not permit the quality or strength necessary for real structures. That is the reason that these areas shift toward concrete masonry as a cost effective structural material that uses local materials.

Some countries, like China as early as 1995, have adopted an official position of using concrete masonry for the approved wall material over brick because of quality, local availability, energy cost to produce, preservation of land, pollution and flexibility of design. Of course, the use of wood in walls is discouraged because of ecologcal reasons.

Concrete masonry units can be made to high strengths in almost every area of the world. The demand is based on the simple economics of the structure, locally available materials and preference for masonry over lightweight wall materials.

Getting back to the original post, depending on the size and use of the building, the building could be built to be functional. The columns seem to be oversized unless it is over 2 stories. I would be concerned about the floor system if the local concrete is limited by the apparent size of concrete pours and construction techniques.

If there was some additional information on the location and available materials it would be possible to make better suggestions to the original poster.

 

[Zambo]

concretemasonary,

I think I misunderstood your point. In the picture we have first floor RC columns with brick infill. Are you saying that the columns were not needed and if available hollow blocks with bond beams and stiffeners could have been used? If so I agree.

But as infill panels bricks - clay, mud, soilcrete are cheap.

As for the structure who knows how the floor slab rebar and connections between columns and slab have been made.

 

[concretemasonry]

Zambo -

I assume the friend was concerned about the building and wanted to kow what options were available to strengthen it if necessary.

I was pointing out that if there was a problem, it could be possible to use some lightly reinforced infill panels to absorb some of the loads due to column and slab inadequacy. Concrete block are lighter, structural and permit an economical option. That area apparently has a tradition of post and slab construction with masonry infill.

If all that was wanted was a material to fill the space between the columns and slabs, then anything would be acceptable. Obviously, dried mud/clay bricks and soilcrete are cheap and adequate if protected from moisture.

Obviously, concrete masonry would work, depending on the interior requirements for open space. For housing or officies it is possible to use loadbearing masonry. In some countries, 6x16" columns are cast and infilled with 6" block to provide access for utilities.

It all gets down to what the poster needs.

Dick

 

[KCRatnayake]

You can see these kinds of structures where the municipal laws are not so strong. I am from Sri Lanka. You can see similar buildings (may be little better than this) in some part of my country as well. But, definitely, not in urban areas.

As dick states, masonry infills are very important. Most of these structures do not fullfil any tie requirement. Devastation is enourmous in case of a tiny earth quake. (Classic example is the Gujrat earth quake)

Most of these constructions are done by hand mix concrete. (volume batching) Virtually no quality control. Therefore, casting columns at one stretch will give more adverse results as they normally do not use tremi pipes. This might lead to segregation of concrete. See how they have patched up the honey combs in some concrete columns.

In my openion, most of these structures survive because they are highly over-designed. (probably not by a structural engineer)

 

[csd72]

I agree with most of the comments above regarding masonry infill, this can act as both a secondary vertical load path and as an infill bracing wall.

As long as the masonry is properly constructed, with a concrete footing under the full length, and full mortar beds, then the structure should be okay.

I assume that the structure is not in a seismic zone.

csd