Geopolymers: Promising Materials For Underground Applications

By Carlos Montes, Trenchless Technology Center | November 2013, Vol. 68 No. 11
Geopolymer coated concrete pipes being subjected to a laboratory-scale Microbial Induced Corrosion test.

Figure 7. Geopolymer coated concrete pipes being subjected to a laboratory scale Microbial Induced Corrosion test.

Another application in which the TTC has been involved is the development of geopolymer-based refractories to be used for slag containment in the gasification industry. This is of special importance when a monolithic refractory is desired to be used.

Figure 8. TTC’s research has enabled geopolymer concrete to be applied with conventional equipment and finished with the same techniques as Portland cement concrete.

Also, geopolymer “mix and pour” ambient cured formulations have been developed as acid spill protection pads for medium and large scale projects. The challenge of the use of large scale equipment has been overcome by the TTC’s proprietary technology which has enabled the production of “geopolymer premix” to be used by installers (Figure 8).

Energy production industry
Even though EPA has increased its regulations for coal burning facilities making it more difficult for producers to keep aging facilities on line, coal is still the main source of electrical production in the United States and around the world. Therefore, high volumes of fly ash are expected to be available in coming years with the ever latent problem of their disposal. Geopolymer technology offers a beneficial alternative for these industries.

Geopolymer also presents itself as an interesting material for the nuclear energy industry, due to its reported ability to encapsulate heavy metals and radioactive waste and provide shielding for radiation. Most of this research has been conducted in Eastern Europe and therefore more research in this area is needed in the United States, but it could possibly provide safer access to nuclear energy.

Geopolymer is an exciting new material that will certainly contribute to the advancement of the construction industry in general and the underground construction industry in particular. The idea of having a material that resembles a manmade rock with its inherent chemical stability is exciting, especially when the advantages of modern construction techniques can be retained.

The Trenchless Technology Center at Louisiana Tech University sees geopolymer as a valuable new tool in the toolkit, able to provide yet another alternative for the construction and rehabilitation of buried infrastructure systems.