Geopolymers possess a chemical plurality in their design that allow the achievement of varied properties depending on demand, both in terms of high-tech ceramic materials and development of constructive solutions. They are obtained from the combination of aluminosilicate precursors and alkaline solutions, with different hardening processes, depending on the curing conditions and chemical balance. In the hardened state, they present a fragile behavior, being then usually reinforced with fibers and aggregates aiming to improve their mechanical performance. As they are relatively new materials, there is a need to accurately assess their capacity under usual and extreme conditions to meet several specific market demands. Such extreme conditions include static and dynamic loading, as well as exposure to high temperatures, which are the major points of analysis in this study. For this, different precursors, such as metakaolin and fly ash, and alkaline solutions, based on sodium and potassium, were studied regarding rheology in the fresh state, and evolution of strength gain according to the curing process used. These were fundamental parameters in the selection of matrices able to achieve an adequate balance between fluidity and viscosity to incorporate 2 percent by volume of synthetic PVA and PE short fibers. The strain-hardening geopolymer composites (SHGC) were then characterized through typical mechanical tests, such as compression, flexural, tensile, pull-out, in quasi-static and impact loadings, and under regular and high temperature exposures (up to 200 C degrees), being further analyzed through imaging and analytical procedures. In general, high reactivity metakaolin combined with Na-based alkaline solutions demonstrated a superior SHGC performance, with and without aggregate incorporation, reaching stress gains and multiple cracking formation when reinforced with both PVA and PE short fibers, the latter being responsible for greater mechanical efficiency when exposed to quasi-static and impact loading. This behavior, however, was not reiterated when exposed to high temperatures, with higher residual strength reductions due to the melting point of PE (at 150 C degrees), opposed to an increased performance of PVA (240 C degrees), being thus more effective at such extreme application. When compared to typical SHCC behavior, SHGC reached greater efficiency both mechanically and thermally, showing unprecedented results in impact loading, thus demonstrating varied application potential.