Efectividad de la prueba con pistón para la evaluación de la adherencia asfalto-agregado.

Abstract

The starting point to analyze the operation of the mixture is found in the aggregate mineral – asphalt binder system, especially in the quality and subsequent preservation of adhesion that occurs between them. For this reason, the objective of this work is to experimentally assess the effectiveness of the piston adhesion test (PAP) with improved grip system, for the direct evaluation of the asphalt binder’s take-off resistance with samples of five types of rocks ( Limestone, Argilita, Granite, Andesite and Slate). The asphalt employed was the AC-20 obtained from the Esmeraldas’ refinery without additive. The tests were carried out under certain parameters such as: temperature of 25 °C, deformation speed of 25 mm/min in the tensile machine and a thickness of the asphalt film of 0.5 mm between the piston and the rock, performing 7 tests in conditions without immersion and 3 tests with immersion in water for each type of rock. It is concluded that the cohesion failure in the applied method is representative in the samples without immersion in water, while the immersion failure is enhanced by immersion. The highest retained resistances correspond to Granite (97.6%) and Limestone (83.2%), while minor ones to Slate (65.4%) and Argilite (58.3%). It was proved by applying the ‘’Student’s t-test’’ distribution that there are significant differences between using the old and improved jaws, the coefficients of variation being lower with the new jaws.