Development of Corrosion Inhibiting Geopolymers Based Cement for Transportation Infrastructure

Geopolymers are gaining attention as affordable, sustainable, and eco-friendly replacement for Ordinary Portland Cement (OPC) in concrete civil structures. More importantly, Geopolymer-based Cement (GPC) provide sustainable and environmentally friendly alternative to OPCs as GPC can be processed at room temperatures from aqueous solutions of waste materials (e.g., fly ash) or abounded natural sources (e.g., clay) and thus reduce significant CO2 production associated with processing of OPC. Although, a lot of work has been done on improving mechanical properties of GPC over the last two decades, there are only a few studies on effects of GPC concrete on steel rebar reinforcement. Even though all those studies indicate that GPC inhibits corrosion of reinforcing streel when compared to OPC, the inhibition mechanism is still unclear and geopolymer composition is yet to be optimized to achieve the best inhibition properties. A collaborative research study is formulated by a team from TAMU to investigate the long-term durability of reinforced GPC concrete against chloride-induced corrosion. Various parameters of GPC such as Si/Al, water/solids, alkali ion/Al ratios would affect various structural and mechanical properties of GPC. Therefore, GPCs will need to be studied thoroughly in order to optimize the use of local waste and natural materials for transportation infrastructure in Region 6. As a part of the proposed study, durability tests under simulated marine environment are to be conducted on reinforced GPC concrete over long periods of time. Both material characterization studies related to micro to macro behavioral changes during long-term exposure of reinforced GPC concrete and steel rebar will be carried out as a part of this research.