Caracterización de las propiedades mecánicas (TRACCIÓN, CHARPY Y METALOGRÁFICAS) de las varillas para la construcción con recubrimiento de hormigón frente a alteraciones térmicas controladas

Abstract

The present experimental work was carried out with the purpose of carrying out a study to the rods for the construction, analyzing their behavior in front of a fire, simulating this fact with controlled thermal alterations and at the same time reinforcing them with a concrete coating being this way in a case of the real life, in such a way the affectation of the material will be determined. In this research the results of the characterization of the mechanical properties (tensile, impact and metallographic) of the concrete coated material will be exposed, the mechanical tests have been carried out under the standards (ASTM E8 / E8M- 16a) for traction, (ASTM E23) for impact. For the preparation of the test pieces that have been tested a specific dosage was taken for the coating, these were designed as a beam species with the measurements of (15x15) cm of base and 46 cm of length, after their curing process they were exposed at temperatures of 650 ° C, 800 ° C and 950 ° C, for a time of 30 minutes once reached each temperature, then they were suddenly cooled in a tank with water at room temperature for 5 minutes, then the concrete was detached and obtain the rods that were inside, to proceed to be rehearsed. The preparation of the specimens was carried out based on the aforementioned standards, for each case of temperature including the standard, 5 samples were taken for each group in such a way that a more accurate result was obtained. In the case of traction results, it was obtained that the breaking strength based on the temperature reached up to 650 ° C will improve, but after reaching a higher temperature, as in the case of 800 ° C and 950 ° C, this resistance will decrease considerably. For the impact test, more variant results have been obtained, such as, for example, at 650 ° C the property the impact resistance improves, in the case of 800 ° C its resistance decreases, but not being less than the standard resistance and at 900 ° C the resistance increases its value again, being higher than previous temperatures. Finally, in the metallographic analysis has determined variation in its microstructures, the microscopic photographs have been taken with magnifications of 100x, 200x and 500x, in such a way that the segmented photography of 100x allowed us to calculate the percentage of pearlite and the percentage of carbon