Saturday, November 30, 2019

Waterstop: Quality Assurance and Installation Failures

Waterstop quality assurance specification should contain the following:
Edge welding will not be permitted. Centerbulbs shall be compressed or closed when welding to non-centerbulb type. Waterstop splicing defects which are unacceptable include, but are not limited to the following:
A. Tensile strength is not less than 60 percent of parent sections.
B. Free lap joints.
C. Misalignment of centerbulb, ribs, and end bulbs greater than 1/16 inch.
D. Misalignment which reduces waterstop cross-section more than 15 percent.
E. Bond failure at joint deeper than 1/16 inch or 15 percent of material thickness.
F. Misalignment of waterstop splice resulting in misalignment of waterstop in excess of 1/2 inch in 10 feet. 
G. Visible porosity in the weld.
H. Charred or burnt material.
I. Bubbles or inadequate bonding.
J. Visible signs of splice separation when cooled splice (24 hours or greater) is bent by hand at a sharp angle.
Below is a gallery of waterstop installation failures.
Snaked waterstop, probably from "wet setting" the waterstop.
Waterstop with cuts for rebar.
Edge welded waterstop failure.
Improper waterstop embedment.
Edge welded waterstop failure.
Waterstop glued together with epoxy.
Waterstop corner install failure.
Waterstop installation failure.
Additional waterstop installation guides can be found here.


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