The present study examines some durability aspects of ambient cured bottom ash geopolymer concrete (BA GPC) due to accelerated corrosion, sorptivity, and water absorption. The bottom ash geopolymer concrete was prepared with sodium based alkaline activators under ambient curing temperatures. The sodium hydroxide used concentration was 8M. The performance of BA GPC was compared with conventional concrete. The test results indicate that BA GPC developes a strong passive layer against chloride ion diffusion and provides better protection against corrosion. Both the initial and final rates of water absorption of BA GPC were about two times less than those of conventional concrete. The BA GPC significantly enhanced performance over equivalent grade conventional concrete (CC).

Flexible and rigid road pavement deteriorates over time and needs high-performance patching repair materials. Cold mix asphalt patching is an easy and inexpensive repair material to repair potholes and other damaged roads. However, the repaired road pavement fails because it doesn’t have adequate compressive and bonding strength to the substrate. Thus, this research uses high-performance geopolymer repair materials to patch against road pavement potholes substrate. Geopolymer repair materials could improve the bonding strength, making them suitable for road repair purposes. For making geopolymer repair materials, the main materials used were high calcium aluminosilicate source materials such as fly ash, sodium hydroxide, sodium silicate, and water. This study tested the compressive and bonding strength of geopolymer repair materials after 1, 7, 14, and 28 days. This study found that the compressive strength of 90 g of alkali activator was the highest, at 37.0 MPa. The bonding strength improved gradually from day 1 to day 14, and then considerably on day 28. The compressive strength and bonding strength both increase in direct proportion to the amount of alkali activator present. Alkali activator is optimal at 90 grams for compressive strength and bonding strength of geopolymer repair materials.

This study examined the self-sensing performance of metakaolin-based geopolymer paste samples activated by an alkali activator, which is a solution mixture of potassium hydroxide and silica fume (SF). Their piezoresistive response under repeated compressive loads was found to improve with increasing SF content. It was found from their XRD, SEM, and FTIR results that the change in the SF content did not alter the phase composition of the geopolymer matrices. The factorial change in the electrical resistivity of geopolymer samples with a maximum SF content was calculated to be about 0.024. Their pore solutions were detected to be mainly filled with potassium and silicon ions due to the use of higher concentrations of SF particles. The UV spectrophotometry measurements of this study confirm that all the geopolymer samples displayed semiconductor behaviour. The SF-derived alkaline activator can enable the self-sensing character of geopolymer-based concrete, which isenvironmentally friendly and has recently shown great potential to monitor structural integrity under applied external loads.