Environmentally Friendly Geopolymer Building Material: Production, Determination of Physical-Mechanical-Radiation Absorption Properties and Mathematical Model Approach

Abstract

Waste ashes and radiation cause important environmental and health problems. Therefore, reduction of their amount is vital. In this study, physical-mechanical and radiation absorption (RA) properties of eco-friendly alkali (NaOH and Na2SiO3) activated geopolymer building material (GPBM) produced by using the industrial solid waste class F fly ashes (FFAs) are determined. The FFAs were supplied from thermal power plants operating in Zonguldak and Adana (Turkey). The sieve analysis, loose/tight unit weight and loss on ignition analysis of the FFAs was conducted. Different FFAs and alkali activator amounts were used for making GPBMs. After thermal curing in a laboratory oven at 70 °C and 100 °C, the produced GPBMs were kept to cool off to room temperature. Afterwards, compressive and flexural strengths, water absorption, porosity tests and RA measurements were performed. Influence of several parameters (FFA types, curing temperature and alkali ratios) on the RA properties of GPBM is discussed in this paper. According to the mathematical model developed in this study, the effect of FFAs supplied from different TPPs onto RA (%) is an important issue. Because FFA quantity causes to increase RA (%) with respect to the composed mathematical model. The FFA-based GPBMs, which have a compressive strength of more than 30 MPa, have higher radiation absorption (>12%) than ordinary Portland cement-based conventional building materials (9.52%). The highest compressive strength and RA percentage were measured as 93.3 MPa and 12.54%, respectively, for the GPBMs that are (properly) suited for the construction sector.