Analysis of Physical and Mechanical Properties of Geopolymeric Concrete with Partial Replacement of Portland Cement by Metakaolin

Essential in civil construction, Portland Cement causes a major environmental impact and energy consumption throughout the life cycle of cementitious materials. Among the materials studied to replace it, metakaolin stands out for obtaining a geopolymer cement with a high silica and alumina content, which achieves properties equal to or superior to Portland cement. This study compares conventional concrete with geopolymer concrete with replacement of 5 and 15% of Portland cement by metakaolin. For this, the mixtures were defined using the American Concrete Institute (ACI) method, analyzing their physical and mechanical properties through tests to determine workability, water absorption, compressive strength, tensile strength by diametrical compression and compressive strength when subjected to high temperatures. The lowest and highest percentages of water absorption were obtained by the mixtures with 5 and 15% of metakaolin (CG5 and CG15), respectively. The CG15 mix also obtained the lowest workability and the highest compressive strength, tensile strength by diametrical compression and compression at temperatures of 25 and 100 °C. Therefore, by ensuring the improvement of the properties of conventional concrete and presenting a lower environmental impact, CG15 proves to be a viable alternative to replace it.