Cracked Concrete Curbs 1

[PEFLWI]

Concrete curbs were poured about 18 months ago are experiencing significant cracking. The curbs are 6 inches wide and 6 inches tall. See the attached photos. Any thoughts on why this would happen? The contractor is claiming that the water stops are causing the problem. See the attached curb detail.

 

[PEFLWI]

See attached Photo.

 

[Ron247]

The picture shows 2 curbs. One appears heavily cracked while the other does not. Are the curbs subjected to possible impact loads from equipment? Is this damage present in multiple locations or isolated to a few curbs?

 

[epoxybot]

I'm inclined to agree with the contractor but the reason the waterstop may be the problem could be poor installation. The slab has a coarse broom finish. If the waterstop was not mechanically attached to the slab and it floated during concrete placement, it could explain the nature of the cracking. The efflorescence at the curb/slab bond line suggests the waterstop is not positioned at the slab elevation. An epoxy bonding agent make a perfectly decent waterstop in such instances.

 

[Canuck65]

Cetco waterstops have minimum requirements for confinement, set by the manufacturer and to be considered at the design stage. It is an expansive material. If you do not have the manufacturers minimum clearance of concrete around the waterstop, the concrete will crack. Any forensic investigation should also confirm that the anchorage of the waterstop material conformed to the manufacturer's requirements. I cannot recall from memory what the minimum clearances are, but I am guessing a 6"x6" curb does not meet the requirements.

 

[MMM]

The cracks on the top and the concrete have two colors is it orrect, so may be the pouring happened with delay time and there is a different cemenet content. But as usually say do not jump the conclusion. So what is about the temperature in summer and winter and the another question is there a vibrating machines near to it. After construction the cracks increase until reach this in the photo or sudden happened. As I think there no eefct to the water stop. The cracks happeneds due to combined in many reasons not just asimple one.

 

[PEFLWI]

Ron 247:
The slab is damaged in multiple locations and are not subject to impact loads. The photos I uploaded are representative of issues at several locations. Thanks!

 

[PEFLWI]

Another photo.

 

[Ron247]

I am not familiar with Cetco waterstops, but Canuck65's post appears likely to be the cause.