Rebar in Foundation and Pillars.

[Bouba]

Curious to find out as seen builders dropping a rebar frame of 10mm in foundation next door.

Will the rebar not rust in about 15-20 years or maybe a bit longer once PH drops in concrete.

Also when the walls are being build in blocks,they are using a pillar with concrete inside on corners with rebars in it,but not tying in the blocks. I have never seen anything like this. Is this new method of construction.

Normally the corner the blocks overlap the one below. Again just curious to find as never seen anything like this in UK.

 

[KenGMac]

Bouba, good evening.

The rebar you refer to in the slab? was it a "mesh"? [best described as a sheet or reinforcing?] or was it single bars, tied together?

in general terms, the designer who specified the diameter of the reinforcing will also specify what so called "cover" is needed to the reinforcing, "cover" is the distance from the external face of the concrete to the nearest bit of reinforcing, the "cover" distance will depend on Concrete strength, ground conditions [Sulphate in the ground Etc.] but a s a rule of thumb a " cover" distance of not less that 20.mm / 25.mm. should be OK and the reinforcing will be protected for its foreseeable future.

As for the block work and the corners??? there is a system / design where hollow blocks are [generally] threaded over [vertical] reinforcing bars which have previously been installed in the foundations or slab.

The vertical reinforcing sticking up out of the foundation / slab as above have the hollow blocks threaded over them, the hollow block is then at a later date filled with Concrete. the rational is that you have created a so called "Stiff" hard area on the wall.

Ken.