Page 368 - Construction Waterproofing Handbook

8.28 CHAPTER EIGHT

FIGURE 8.26 Chemical grout injection. (Courtesy of de Neef Construction Chemicals)

retention ponds. In these applications, materials react with groundwater present, binding
together soil particles.
Grout injected into wetted substrates fills fissures and pores along a crack surface
(Fig. 8.27). Once-cured grouts, similar to sealants, have excellent movement capability
with elongation as much as 750 percent. This flexibility allows material to withstand ther-
mal movement or structural movement at a joint without deterring its waterproofing capa-
bilities. These grouts have been used successfully in remedial below-grade applications
where leakage is occurring directly through a crack itself rather than through entire sub-
strates (Fig. 8.28).
Since water moves through a path of least resistance, during remedial repairs injecting
cracks can redirect water and start leakage in other areas of least resistance. Therefore,
complete remedial waterproofing treatments can require grout injection of cracks and
application of a waterproofing system. (See Table 8.9.)

CHEMICAL GROUT APPLICATION

Chemical grout applications are very similar to epoxy injection, with similar equipment
and injection tubes necessary. The major difference is that grouts require water and epox-
ies do not. Additionally, chemical grouts are supplied in one-component rather than two-
component epoxy formulations.
Substrate preparation is almost unnecessary with chemical grouts. Surfaces do not need
to be dry, but should be cleaned of mineral deposits or other contaminants along a crack