Concrete future - Concrete Mix Design, Quality Control and Specification - page 299

Figure 13.4 Precast geopolymer retaining walls for a private residence.
Figure 13.5 In situ water tanks cast with blended cement concrete (left) and geopolymer
concrete (right).
One reason was to investigate the autogenous healing behaviour of this
geopolymer concrete. Autogenous healing in Portland-cement-based con-
crete is primarily due to the deposition of calcium hydroxide. As there is very
little calcium hydroxide present in the geopolymer mix, the performance
of geopolymer concrete in a water retaining application is of considerable
interest.
Nominal leaking through cracks in the geopolymer tank did heal rela-
tively rapidly. Ahn and Kishi (2010) suggest that geomaterials may be able
to autogeneously heal due to a gel swelling mechanism.