Evaluation of municipal solid waste incineration fly ash based geopolymer for stabilised recycled concrete aggregate as road material
Wisitsak Tabyang, Cherdsak Suksiripattanapong, Chayakrit Phetchuay, Chuthamat Laksanakit, Nuntachai Chusilp
Abstract
This research investigates the possibility of using municipal solid waste incineration fly ash (MSWI FA) geopolymer to stabilise the strength of recycled concrete aggregate (RCA) in pavement applications. The unconfined compressive strength (UCS) and scanning electron microscope were studied in this research. The maximum dry unit weight of RCA-MSWI FA geopolymer specimens increased as MSWI FA replacement increased due to the filler effect of MSWI FA. For MSWI FA higher than 20, the maximum dry unit weight of samples decreased with MSWI FA replacement due to the lower specific gravity of MSWI FA. The optimum ingredient of RCA-MSWI FA geopolymer specimens is at optimum liquid content (OLC), RCA/MSWI FA of 90/100, and all sodium silicate (Na2SiO3)/sodium hydroxide (NaOH) ratios which meet the 7-day UCS requirement of pavement base material for the low-volume road. There is one ingredient for the high-volume road: OLC, RCA/MSWI FA of 90/100, and Na2SiO3/NaOH of 60/40.