Cold joints in concrete

[jwright81]

I am revieweing a residential structure and a cold joint has been noted around the ENTIRE exterior of the home.

It is my uderstanding that 2 hours passed between pours and honeycombing has appeared all the way around the exterior of the home.

Does anyone have anything to say about cold joints of this nature?

My main concern is with the shear strength of the joint however this is a 1 story residential structure. The actual slab part was monolithic but the grade beams were about 3/4 poured, then 2 hours went by, then they were finished.

 

[Ron]

Generally, the grade beams do not have to bond to the slab concrete. As long as the slabs are in full contact with the grade beams, it shouldn't be an issue UNLESS you happen to be in an expansive clay soil.

 

[mcutchi]

If the grade beams have closed ties, they would project through the cold joint into the slab, hence shear transfer is effected. Also the two are tied together, mitigating what Ron said about expansive clays possibly lifting the slab off the beams. My concern would be durability, since we now have a porous joint at the worst place - the ground-air interface.