Mechanical and Thermomechanical Evaluation of Geopolymeric Concrete Derived from Demolition Waste and its Comparison with Conventional Portland Cement Concrete

Huamán-Mamani F.A.; Palomino-ñaupa C.K. · Nanotechnology Perceptions (2024) · DOI: 10.62441/nano-ntp.v20is3.64

Resumen

Brick, mortar and concrete demolition wastes were mechanically treated by crushing, grinding and screening processes, and then used as raw material in the manufacture of geopolymer cements, which were subsequently used for the manufacture of geopolymer concretes by adding controlled amounts of aggregates and sodium hydroxide solution. At the same time, conventional Portland cement concretes were manufactured. All the manufactured concretes, conventional and geopolymeric, were evaluated by optical microscopy, finding similarities between both materials, with the presence of two well differentiated phases, on the one hand, a continuous binder phase and, on the other hand, a phase of aggregates enveloped by the binder phase. The studied concretes were mechanically and thermomechanically characterized in a single prototype equipment, finding for both types of materials a systematic softening with increasing test temperature, from ambient to 350 °C, and then a hardening of the materials with increasing test temperature from 350 to 550 °C. The mechanical aspects evaluated were maximum strength, stiffness and degree of deformation. In the comparison between the two types of concrete studied, a better mechanical response was found in the conventional concrete. Finally, with the apparent and real density data (obtained by helium pycnometry), the porosity of the materials was determined and the influence of porosity on the mechanical response of the materials was analyzed.

Instituciones: Universidad Católica San Pablo