Eco-Geopolymers: Physico-Mechanical Features, Radiation Absorption Properties, and Mathematical Model

Area of Science:

• Materials Science
• Environmental Science
• Nuclear Engineering

Background:

• Waste ashes and radiation pose significant environmental and health risks.
• Developing effective barriers against radioactive radiation is crucial for safety and disposal.

Purpose of the Study:

• To investigate the production and properties of eco-geopolymer building materials (GPBMs) using class F fly ashes (FFAs).
• To evaluate the effectiveness of these GPBMs as barriers against radioactive radiation.
• To optimize GPBM production for enhanced mechanical strength and radiation attenuation.

Main Methods:

• Testing various production methods, FFA to alkali activator ratios, and curing temperatures.
• Analyzing the impact of fly ash characteristics (particle size, SiO2 content) on reactivity.
• Measuring compressive strength and radiation attenuation (RA) of developed GPBMs.
• Developing a mathematical model to correlate FFA quantity, mechanical properties, and RA.

Main Results:

• Isken TPP FFA exhibited higher reactivity than Catalagzi TPP FFA due to its particle characteristics.
• Lower activator concentration (10%) and curing temperature (70 °C) increased GPBM compressive strength, reaching up to 93.3 MPa.
• Highest radiation attenuation (RA) was achieved with an alkali activator ratio (Na2SiO3/NaOH) >2 and 20% concentration.
• FFA quantity and GPBM mechanical properties were identified as key factors influencing RA.

Conclusions:

• Lightweight GPBMs derived from fly ash are suitable for the construction sector, particularly for radionuclide immobilization, storage, disposal, and radiation shielding.
• Careful optimization of the multi-step production process is essential for maximizing the performance of these materials.