Performance comparison of carbon footprint and dielectric properties of geopolymer mortars with portland cement mortars

Abstract

Building constituents used in the construction industry, peculiarly cement and concrete, generate significant carbon emissions. CO2 discharges from cement constitute approximately 5–9% of global expelling. Geopolymer is a retainable and eco-friendly innovative constituent developed as an option to Portland cement concrete using waste constituents. Therefore, this examination investigated the life cycle carbon emissions and dielectric properties of geopolymer mortars used to reduce climate change and carbon emissions from building materials. The investigation investigated the carbon emission and electromagnetic wave resistance of obsidian-based silica fume-substituted geopolymer mortars using 12 M NaOH as alkali activator. All these properties were compared with Portland cement mortars. When comparing geopolymer and OPC mortars, it was detected that the CO2 emissions of geopolymer mortars were very low compared to OPC mortars. In addition, when 28-day values were considered, mechanical strength and CO2 emissions were evaluated together, and as a result, geopolymers yielded lower kg CO2-eq/MPa values in the range of 66.45%-73.01% compared to the contents of the mixtures. These values show that geopolymers are more environmentally friendly and high performance building materials than OPC mortars.This study investigated the dielectric and electrical properties of standard and modified mortars for high-frequency applications. Measurements were performed up to 888 h of curing using a Vector Network Analyzer (VNA) to obtain Scattering parameters, complex permittivity, loss tangent, and conductivity. The dielectric constant of mortar in control group decreased from 4.161 to 3.340 in 28 day, and its conductivity fell from 34.226 mS/m to 21.891 mS/m. Modified mixtures began with lower initial values but increased and stabilized above the control's final values. Mix 1 demonstrated superior shielding, showing 0.60 normalized signal attenuation through 30 cm, while the control showed 0.50 attenuation. The results obtained from this study demonstrate that geopolymers are not only sustainable and environmentally friendly materials in general, but also measurably reduce CO2 emissions by 66.45%–73.01% and provide higher electromagnetic shielding performance with a normalised signal attenuation of 0.60. Therefore, geopolymers offer significant potential for both reducing the carbon footprint and high-performance building applications requiring electromagnetic protection.