Geopolymers are inorganic alumino-silicate polymers that come from chemical reactions under highly alkaline conditions between an active puzzolanic material (such as fly ash or metakaolin) and an activator solution (based on a molar mixture of sodium hydroxide and an alkaline silicate). Geopolymers are known for their excellent mechanical properties, high corrosion resistance, and chemical stability. Geopolymers are produced out of industrial byproducts rich in alumina and silica, such as fly ash. Geopolymers' excellent properties make them excellent replacements for Portland cement in most applications. While geopolymers require little or no energy for their final use, Portland cement is one of the most energy-consuming industries in the world. Portland cement emissions of CO₂ to the atmosphere currently rise up to 7% of the world's total emissions of this gas. The technologies of the new millennium must be based on environmentally friendly materials that can build sustainable development for the centuries to come.

Concrete pipes in storm and wastewater collection in North America are in various stages of deterioration, generally due to microbiological-induced corrosion or mechanical loading (either external or internal). Open-cut replacement of these pipes, many placed beneath busy streets, is costly and involves a lengthy disruption to normal traffic and business activates. Common rehabilitation techniques for such structures include coating using epoxy-based or cementitious-based materials. The latter is in many cases the most economical approach, but the durability of most cementitious lining products in harsh environments limits their useful design life. Hybrid materials, such as polymer concrete, provide superior performance but at higher costs.

The paper provides a state-of-the-art review of geopolymer cement and its chemical and mechanical properties. Thereafter, an experimental testing program will be undertaken to explore the suitability of this material for use as coatings for wastewater conveyance.