Page 373 - Construction Waterproofing Handbook

REMEDIAL WATERPROOFING 8.33
crack. These materials set in an extremely short time due to this internal chemical curing,
which dries the material rapidly. This property enables these materials to patch cracks that
exhibit running water in concrete or masonry.
To complete repairs to substrates, leaking cracks are sawn out, approximately 1 1 in
(Fig. 8.34). This groove is then packed with hydraulic cement, regardless of any running
water present (Fig. 8.35). The material sets in approximately 5 minutes, in which time leak-
age is effectively sealed (Fig. 8.36). Should water pressure be great enough to force patch
material out before initial set, relief holes must be drilled along the crack to redirect water
(Fig. 8.37). These holes will continue to relieve water pressure until the crack patching has
cured, after which relief holes themselves are patched to stop water infiltration completely.
These products are also used to seal portholes in epoxy and chemical grout injections.
Hydraulic materials are often used in conjunction with negative cementitious waterproof-
ing applications to complete substrate patching before waterproofing material application.

FIGURE 8.34 Crack repair preparation of existing substrate. (Courtesy of Vandex)

FIGURE 8.35 Application of hydraulic cement to stop leakage. (Courtesy of Vandex)