Determining the suitability of fly ash for use in geopolymer concrete
- Kevin Conway (Oak Forest High School)
- David Kavalauskas (Tinley Park High School)
- Brenden Kelly (Tinley Park High School)
- Elizabeth Klimek (Tinley Park High School)
- Joseph Muller (Oak Forest High School)
- Abigail Zatkalik (Tinley Park High School)
- James Birrell (Tinley Park High School)
- Volker Rose (Advanced Photon Source & Center for Nanoscale Materials)
In our experiment, we analyzed a fly-ash based geopolymer concrete using x-ray fluorescence in order to determine the concentration of chromium in a fly-ash geopolymer as well as in Portland cement. The hard x-ray nanoprobe at the Advanced Photon Source was used in our experiment because it allows extremely accurate measurements of quantity and location of heavier (Z ≥18) elements at the nanoscale.
We determined that the fly-ash based concrete had approximately twice as much chromium as a sample of Portland cement. Superimposing images of Fe concentrations with Cr concentrations shows that the Cr may stay clumped together with the Fe and not disperse throughout the matrix.
Further testing should be done on both Portland cement and fly-ash based geopolymer to definitely determine the location and bonding state of Cr in concrete.