Evaluation of the potential of geopolymer mortar in the rehabilitation of buried infrastructure

Abstract

Concrete pipes represent the backbone of the wastewater collection systems in many cities across North America. These pipes are in various stages of deterioration, generally due to microbiological induced corrosion and/or mechanical loading. A common method of rehabilitating these structures is the use of cementitious coatings. This paper describes the development and testing of three novel geopolymer mix designs prepared using metakaolin and fly ash (class C and F) precursors. Specimens prepared using Portland cement-silica fume blend were also tested for comparison purposes. The specimens were placed in several concentrations of sulphuric acid for a period of eight weeks. The corrosion resistance and remaining compressive strength of geopolymer mortar made from class F fly ash precursor were found to be substantially higher compared with the enhanced OPC formulation. The other geopolymer mix designs were found to perform equally or better compared with the OPC binary blend.