title: Feasibility of manufacturing geopolymer bricks using circulating fluidized bed combustion bottom ash.
abstract: This paper presents a study on geopolymer bricks manufactured using bottom ash from circulating fluidized bed combustion (CFBC). The alkali activators used for synthesis were sodium silicate, sodium hydroxide, and potassium hydroxide and lithium hydroxide solutions. The study included the impact of alkali activator on compressive strength. The reaction products were analysed by XRD, FT-IR and SEM/EDS. The compressive strength of bricks was dependent on the modulus of the sodium silicate activator and the type and concentration of alkali activator. The highest compressive strength could be gained when the modulus was 1.5, and the value could reach 16.1 MPa (7 d after manufacture) and 21.9 MPa (28 d after manufacture). Under pure alkaline systems, the compressive strength was in the order of 10 M KOH > 10 M NaOH > 5 M LiOH > 5 M KOH > 5 M NaOH. Quartz was the only crystalline phase in the original bottom ash, and no new crystalline phase was found after the reaction. The main product of reaction was amorphous alkali aluminosilicate gel and a small amount of crystalline phase was also found by SEM.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.forename: Lifeng
authors.initials: L
authors.lastname: Shen
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhai
mesh_terms: D060729:Coal Ash / Q000737:chemistry*; D019245:Compressive Strength; D003252:Construction Materials; D005240:Feasibility Studies; D007220:Industrial Waste; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D060729:Coal Ash; D007220:Industrial Waste