Mechanical and Electromagnetic Properties of Self-Compacted Geopolymer Concretes With Nano Silica and Steel Fiber Additives

Mechanical and electromagnetic properties (over 2–16 GHz) of self-compacted geopolymer concrete (SCGC) samples with different amounts of nanosilica (NS) and steel-fiber (SF) have been examined. From the mechanical tests, it is observed that, while the amount of NS added to SCGC samples does not make any noticeable change in compressive strength and modulus of elasticity values, an increase in the amount and/or aspect ratio of SF additives improves these values. From the electromagnetic tests, it is noted that the effect of SF on the reflection properties of SCGC samples is relatively smaller than the effect of NS. Besides, while the incorporation of NS improves the resonance characteristics of transmission properties, additives of SF decrease these properties over the entire frequency band. Finally, sample C7, which has 1% SF with a smaller diameter and 2% NS in reference to the mass of the binder, has the optimum NS and SF additives, producing maximum absorbance values.