Page 190 - Construction Waterproofing Handbook

ABOVE-GRADE WATERPROOFING 3.79

FIGURE 3.79 Sandwich-slab membrane penetration detailing. (Courtesy of Tamko Waterproofing)

Typically, waterproofing systems used on these types of structures is limited to cemen-
titious or clear repellents, though some elastomeric coatings and sheet systems can be
used. Figs. 3.81 and 3.82 detail the typical application of a cementitious coating to a bride
structure.
On other civil projects including tunnels and water reservoir, most of the below-grade
and above-grade systems are used as appropriate, Fig. 3.83. The application methods are
also the same as addressed in the previous sections and chapter. For instance, a water
retaining structure above grade might use negative-side cementitious coatings, while any
below-grade portions of the structure might be protected by positive-side systems includ-
ing clay, liquid membranes, or sheet-goods.
Figure 3.84 shows a liquid membrane being sprayed on the interior of a water-retaining
civil structure. Since it is a negative application, the membrane would have to be accept-
able for potable water containment.
Landfill, pond linings, earthen reservoirs and other environmental protection projects
are increasingly using standard and modified waterproofing systems to provide the neces-
sary protection. The waterproofing systems in these situations provide protection from ero-
sion in ponds, leaching from contaminant placed in landfills, and other nontraditional uses
for waterproofing systems. Figure 3.85 shows the use of a drainage matting that is used to
collect the discharge from the landfill and divert it into receptor drains that can direct the
water to facilities designed to treat the water before it is discharged.
This traditional waterproofing system, while being used to prevent water intrusion in
this case back into the earth, is also providing a nontraditional use as a collector system for
the landfill water runoff so that it can be properly treated. Figure 3.86 details the use of the
prefabricated drainage mat on earth structures.