Prediction total specific pore volume of geopolymers produced from waste ashes by fuzzy logic

Abstract

In the present work, total specific pore volume of inorganic polymers (geopolymers) made from seeded fly ash and rice husk bark ash has been predicted by fuzzy logic. Different specimens, made from a mixture of fly ash and rice husk bark ash in fine and coarse form together with alkali activator made of water glass and NaOH solution, were subjected to porosimetry tests at 7 and 28 days of curing. The curing regime was different: one set of the specimens were cured at room temperature until reaching to 7 and 28 days and the other sets were oven cured for 36 hours at the range of 40-90 °C and then cured at room temperature until 7 and 28 days. A model based on fuzzy logic for predicting the total specific pore volume of the specimens has been presented. To build the model, training and testing using experimental results from 120 specimens were conducted. The used data as the inputs of fuzzy logic models are arranged in a format of six parameters that cover the percentage of fine fly ash in the ashes mixture, the percentage of coarse fly ash in the ashes mixture, the percentage of fine rice husk bark ash in the ashes mixture, the percentage of coarse rice husk bark ash in the ashes mixture, the temperature of curing and the time of water curing. According to the input parameters, in the fuzzy logic model, the pore volume of each specimen was predicted. The training and testing results in the fuzzy logic model have shown a strong potential for predicting the total specific pore volume of the geopolymer specimens in the considered range.

Split tensile strength of slag-based geopolymer composites reinforced with steel fibers: Application of Taguchi method in evaluating the effect of production parameters and their optimum condition

“…Steel fibers were added to the mixtures just before casting in molds. Specimens were then preserved for 24 h at room temperature because this precuring time has been found to be beneficial to strength development [18] Precuring time before application of heat induces significant dissolution of silica and alumina from slag mixture and formation of a continuous matrix phase, this increasing homogeneity of the geopolymeric material [18,19]. After the precuring process, the samples cured in oven at 70 ºC for 6h.…”

Processing and Characterization of PET Composites Reinforced With Geopolymer Concrete Waste

“…These authors observed the trend of strong degradation of the PET during processing due the presence of organic modifier, a slight increase in crystallinity and a slight change on Young's modulus for all clay contents below 10 wt%. 10,11,12 . The purpose of this study was to develop composites containing high amounts of pulverized geopolymer concrete waste, treated and untreated with oleic acid.…”

Physicochemical Characterization of Pulverized Phyllite Rock for Geopolymer Resin Synthesis

“…Metakaolinite, present in metakaolin (MK), is the main source of aluminum in the geopolymer. The geopolymerization occurs due to the destruction and recombination of the aluminosilicate chains of the disorganized kaolinite (metakaolinite) from the action of OH -ions and alkalis, specifically in the aluminum-containing sites 5 . Therefore, any impediment to this reaction, such as the entrapment or insufficiency of ions or the substitution by impurity atoms in the original kaolinite structure, can modify the kinetics of the geopolymerization and even hinder obtaining the necessary structural properties in the geopolymer 5 .…”

“…The geopolymerization occurs due to the destruction and recombination of the aluminosilicate chains of the disorganized kaolinite (metakaolinite) from the action of OH -ions and alkalis, specifically in the aluminum-containing sites 5 . Therefore, any impediment to this reaction, such as the entrapment or insufficiency of ions or the substitution by impurity atoms in the original kaolinite structure, can modify the kinetics of the geopolymerization and even hinder obtaining the necessary structural properties in the geopolymer 5 . In the Brazilian Civil Construction market, there has been a recent increase in the supply of the phyllite ore, integrating ready-mixed sand mortars and additives for use in coating mortars and laying of red ceramic masonry.…”