Strength Properties Of Geopolymers Research Articles

Temperature-Dependent Compressive Strength Modeling of Geopolymer Blocks Utilizing Glass Powder and Steel Slag

This article investigates the development of geopolymers as a modern, environmentally sustainable binder with ceramic-like properties, offering exceptional thermal and fire-resistant characteristics. The study primarily utilized fly ash (FA) in combination with glass powder (GP) and steel slag (SS). The SS content varied between 30% and 40%, while the molarity of NaOH was set at 10M, 12M, and 14M. Based on these variables, a total of 18 mixes incorporating GP and SS were formulated. The samples were subjected to elevated temperatures of 200 °C, 400 °C, 600 °C, and 800 °C, after which their compressive strength was measured. To better understand the material formation, scanning electron microscopy and energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetry differential thermal analysis analyses were conducted. The study aimed to examine the influence of oxide ratios (Na/Si, Si/Al, H2O/Na2O, and Na/Al) on compressive strength at elevated temperatures. Additionally, the research sought to develop a predictive model, elucidating the relationship between these oxide ratios and compressive strength of geopolymers. To achieve this, ten machine learning techniques were applied, revealing the complex connection between oxide ratios and the strength properties of geopolymers. The support vector regressor (SVR) model outperformed other regression and boosting models, achieving a high coefficient of determination (R2) value of 0.95, indicating superior predictive accuracy. The reduced error levels and high R2 values highlighted the enhanced performance of the SVR model. A sensitivity analysis was done to understand the contributions of each parameter to the outcome predictions further. Employing machine learning techniques to forecast compressive strength of geopolymer blocks under various elevated temperature conditions improves predictive accuracy and optimizes resource utilization, leading to significant time savings.

The Influence of Diatomite Addition on the Properties of Geopolymers Based on Fly Ash and Metakaolin.

Geopolymer materials, considered to be an alternative to Portland cement-based concretes, can be produced from various types of waste aluminosilicate raw materials. This article presents the results of research related to the use of diatomite as an additive in geopolymers. The results of testing geopolymer composites with 1%, 3%, and 5% additions of diatomite with a grain size of 0-0.063 mm after and without thermal treatment were presented. This article presents the physical properties of the diatomite additive, the morphology of diatomite particles SEMs, thermal analysis, and compressive strength test results. In this research, diatomite was treated as a substitute for both fly ash and metakaolin (replaced in amounts of 1 and 3%) and as a substitute for sand introduced as a filler (in this case, 5% of diatomite was added). As a result of this research, it was found that the addition of diatomite instead of the main geopolymerization precursors in amounts of 1 and 3% had a negative impact on the strength properties of geopolymers, as the compressive strength was reduced by up to 28%. The introduction of crushed diatomite instead of sand in an amount of 5% contributed to an increase in strength of up to 24%.

Research on strength properties of geopolymer based on tungsten mine waste and recycled ground glass

Introduction: Geopolymers are the modern inorganic materials obtained as a result of chemical reaction under strongly alkaline conditions. The main advantages of these materials are: high strength parameters, fire resistance, frost resistance and resistance to aggressive environment. Because of lower CO2 emission during production process, they are also considered as environmentally friendly materials in comparison to ordinary Portland cement (OPC) systems. Objectives: The aim of the investigation was to define the impact of recycled ground glass addition on mechanical properties of geopolymeric binder made from tungsten mine waste. Methods: The strength parameters of geopolymeric samples were determined on the basis of three-point flexural test and uniaxial compression test. Results: The geopolymer samples that contain 20%, 40% and 80% of recycled ground glass present similar flexural strength. The compressive strength of glass-based geopolymers increases with growing content of recycled ground glass. Conclusions: In terms of flexural strength, the most favourable composition was the mixture composed of 60% recycled ground glass and 40% tungsten mine waste. In terms of compressive strength, the most favourable composition was the mixture composed of 80% recycled ground glass and 20% tungsten mine waste.