| Autor: |
Kwad, Nawfal F., Abdulkareem, Ahmed H., Ahmed, Taher M. |
| Předmět: |
|
| Zdroj: |
AIP Conference Proceedings; 2024, Vol. 3009 Issue 1, p1-10, 10p |
| Abstrakt: |
The interest in recycling waste materials increasing globally. The use of recycled asphalt pavement (RAP) could be more efficient with geopolymer materials. Fly ash (FA) and kaolinite (Kao) materials are known as geopolymer raw materials. This study investigates the effect of wetting–drying (w–d) cycles on the durability as well as the microstructure of the RAP-geopolymer in the subgrade material. In addition, the strength characteristics were determined by the unconfined compressive strength (UCS) test. A sandy silt soil with a plasticity index of 11% was used in this study. Various soil-RAP-geopolymer mixtures were activated by an alkaline solution consisting of the NaOH at 8 molarity and NaOH: Na2SiO3 liquid. Soil-cement mixture was prepared and tested as a reference mix. The results showed a great improvement in the strength of the soil in terms of the UCS. The stabilized FA-based geopolymer, and RAP-FA-based geopolymer passed the durability test by a weight loss less than 10% and a volume change less than 2% as per ASTM standards. Specimens stabilized by the RAP-Kao-based geopolymer passed the wetting and drying cycles without remarkable weight loss or volume change while the Kao-based geopolymer did not pass. The microstructural analysis by scanning electronic microscope (SEM) images proved the formation of the geopolymer binder irrespective of the raw material of the geopolymer. The overall performance of the fly ash-based geopolymer and RAP mixtures was much better than the kaolinite-based geopolymer in terms of the strength and the durability. The fly ash geopolymer can be considered as an effective method to stabilize the fine-grained soil to use in the subgrade layer material. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
