Determinación de la composición óptima para la elaboración de ladrillos prensados en seco (dry-press) como alternativa al proceso de moldeo convencional (soft-mud)

Abstract

The objective of this research was to determine the optimal composition and pressure for the production of dry-pressed bricks (Dry-Press) as an alternative to the conventional molding process (Soft-Mud). For this, first the characterization of the raw material (black earth and white earth) by x-ray fluorescence was carried out. Second, nine design points were established with the help of the Geogebra program to make the design of mixtures. Then, twenty-seven study samples were made, varying their molding pressure (500, 1000 and 1500 psi). Once the samples were made, they were fired in a muffle at 900 degrees Celsius for twenty-five hours. With the samples already fired, the necessary compression tests were carried out to perform the first statistical analysis in the Statgraphics program, in order to achieve the optimal mixture to maximize the compressive strength of the bricks. Afterwards, a single categorical factor design of experiments was carried out in the statistical program with the optimal mixture obtained previously, in which nine more samples were made, varying the molding pressure (500, 1000 and 1500 psi). These samples were cooked and tested in the same way as the first ones, to finally carry out the statistical analysis of the second design. From the first design, it was obtained that the optimal composition is 95% black earth and 5% water, since it gives a resistance value of 8.01438 MPa, which complies with the NTE INEN 297; while, of the second design, the best molding pressure is 1000psi. Concluding that, the best resistance results are presented, with mixtures with 95% black earth and 5% water, and with a molding pressure of 1000 psi. It is recommended to make more samples by varying the molding pressure between 1000 and 1500 psi.