Main factors affecting mechanical characteristics of geopolymer revealed by experimental design and associated statistical analysis

This manuscript adopts experimental design and statistical analysis to quantify the influence of componential factors and associated interactions on mechanical characteristics for a geopolymer. Microstructural analyses are performed for geopolymers with contrasting mechanical parameters to interrelate with mechanical characteristics. Results show that the impact factor of uniaxial compressive strength (UCS) of the geopolymer is primarily OH-(M), which has an interactive effect with SiO2 (mol), followed by Na2O (mol). On the Fourier transform infrared spectroscopy spectrum, the geopolymer has an obvious peak in the Si-O-Si (Al), Si-OH, and AlO2 groups at wavelengths of 980, 862, and 680 cm(-1), respectively. The Si-29 and Al-27 nuclear magnetic resonance analyses demonstrate that the main structure of the Si ion in the geopolymer present in a form of Q(4)(3Al) and Al(4) signal appears generally. The percentage of the Q(4)(4Al) and Q(4)(3Al) in the structure is the major factor impacting the mechanical characteristics of the geopolymer. (C) 2013 Elsevier Ltd. All rights reserved.