Manufacturing By-Products as Partial Replacement in Metakaolin-Based Geopolymer Mortar Production

Geopolymer technology is a new, sustainable approach for producing binding materials without using any cement content. Cement production has negative environmental effects in addition to the large amount of energy and nonrenewable resource consumption; therefore, the use of waste-materials is highly valued in geopolymer production. Using waste materials for production has the potential to reduce waste disposal costs and landfills effects on the environment. Within the same context, red mud (RM) is a waste material that is abundantly available in Turkey and around the world. Thus, it is critical to investigate the use of RM and other waste materials that can affect agriculture and groundwater in the construction industry. This study investigates the strength and durability properties of binary and ternary geopolymer mortar composites of metakaolin (MK) and three different waste by-products (RM, rice husk ash, and waste glass powder (GP)), which are abundantly available in Turkey. Further, this dissertation discusses the effects of high temperature on geopolymer mortar properties and the impact of adding two different sizes of glass fibers (GFs) by 0.3% volume to a geopolymer produced using MK and partially replaced by RM and GP. The GFs have been selected due to the cheap price and high flexibility and strength. Moreover, the dissertation explores the strength properties of the produced mortar in sea water and sulphate environments. Finally, the effect of the sand-to-binder (S/B) ratio on the strength and durability properties under different conditions and environments are investigated. The results indicate that the significant strength properties of the geopolymer mortar can be obtained by binary and ternary composites of MK, RM, and GP. The addition of GFs improves the strength properties of the produced mortar; the addition of 12 mm GFs improves the strength more than that using the 6 mm GFs. However, S/B ratio affects the strength properties significantly, and the results indicated that an S/B ratio of 2.5 is better than that of 2.25. The produced geopolymer is applicable under severe conditions such as high temperature, magnesium sulphate, freezing–thawing, and sea water environment.