Microstructural and thermal characterization of polyethylene and basalt fiber-reinforced natural zeolite-based engineered geopolymer composites

This study examined the effects of hybrid fibers (polyethylene and basalt) on the performance of engineered geopolymer composites (EGC) activated with 12 M solution and subjected to elevated temperatures (200 degrees C, 400 degrees C, and 600 degrees C for two hours). Compressive strength (CS), flexural strength (FS), mass loss, and micro- structural changes were evaluated using SEM and XRD analyses. The results demonstrated that basalt fibers (BF) significantly improved both CS and FS, with a 10.6 % increase in CS observed at an optimal hybrid ratio of 0.5 % BF and 0.5 % polyethylene fibers (PE). Exposure to elevated temperatures reduced CS, with minimal degradation observed at 200 degrees C for 1 % BF, while higher temperatures caused more pronounced reductions, particularly in samples with higher PE content. SEM and XRD analyses revealed increased porosity and notable morphological changes after heating.