This research investigates the simultaneous impact of two different types of steel fibers, nanometakaolin, and nanosilica on the mechanical properties of geopolymer concrete (GPC) mixes. To achieve this aim, different geopolymer concrete mixes were prepared. Firstly, with and without nanomaterials (nanosilica and nanometakaolin) of 0, 2%, 4%, 6%, and 8% from ground granulated blast furnace slag (GGBFS) were used. Secondly, steel fiber (hooked end and crimped) content of (0, 0.5%, 1, and 1.5%) was used. Thirdly, optimum values of nanomaterials with the optimum values of steel fiber were used. Crimped and hooked-end steel fibers were utilized with an aspect ratio of 60 and a length of 30 mm. Geopolymer mixes were manufactured by using a constant percentage of alkaline activator to binder proportion equal to 0.45 with GGBFS cured at ambient conditions. For alkaline activator, sodium hydroxide molar (NaOH) and sodium hydroxide solution (NaOH) were used according to a proportion (Na2SiO3/NaOH) of 2.33. The hardened concrete tests were performed through the usage of splitting tensile strength, flexural, and compressive experiments to determine the impact of steel fibers, nanometakaolin, and nanosilica individually and combined on performance of GPC specimens. The results illustrated that using a mix composed of the optimum steel fibers (1% content) accompanied by an optimum percentage of 6% nanometakaolin or 4% nanosilica demonstrated a significant enhancement in the mechanical properties of GPC specimens compared to all other mixtures. Besides, the impact of using nanomaterials individually was found to be predominant on compressive strength on GPC specimens especially with the usage of the optimum values. However, using nanomaterials individually compared to using the steel fibers individually was found to have approximately the same splitting tensile strength and flexural performance.

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Concrete is probably the most extensively used construction material in the world. The modern concept of construction is directed at the use of recycled materials, in particular, various waste products. This solves a number of problems -saving the expensive materials; - decreasing CO2 emissions by reducing the production of construction materials, so, these can also be used as refractory materials. Plant fibers are the most abundant fiber among all the natural fibers. Bamboo, palm, sisal, jute, date kernel, flax etc. are the commonly known plant fibers. Plant fibers are also called cellulosic fiber and have quite promising tensile strength. Natural Plant fibers treated by pyrolysis in concrete such as additions; determine the effect of these substances and the effect of temperature on the properties of concrete. The natural fibers in concrete are added accordingly with the percentage of 0.5%, 1%, 1.5% and 2% by weight of cement concrete cubes are tested at the age of 7 and 28 days of curing. Natural waste treated by pyrolysis and different additives on concrete behavior to improve its performance in the future to use in Civil Engineering and Construction World. The optimum result for natural fibers was observed at 1.0% for bamboo and date kernel and 1.5% for palm oil of natural fiber.