Comportamento de material fresado com adição de cimento portland e emulsão

Abstract

In Brazil, the recycling of flexible pavements has been a good alternative for the restoration of an old and deficient roadway network that does not respond to the required efforts any more. The object of this study was the cold recycling because it contributes more for the environmental preservation and it is the most executed and studied technique worldwide. Researches and pieces of work executed in our country have also shown that this recycling, besides restoring the pavement, aggregates resistance to the structure when one or more stabilizers are added to that. In this context, the present essay proposes the study of mechanical features with the addition of stabilizers in the recycling of flexible pavements. The study was developed with samples of materials from the federal motorway BR-116, in the region of Pelotas, a city in the south of the state of Rio Grande do Sul. Samples of a layer of 15,0 cm from recycled pavement which contained approximately 5,0 cm of bitumen coating and 10,0 cm of graded gravel were collected. The mechanical behaviour was analysed through testing reference samples with a simple addition of cement, asphalt emulsion and even with a combined addition of both elements. The Indirect tensile Strenght for mixtures of simple addition of cement got ten times greater results compared to the mixtures with simple addition of emulsion. The Resilience Module for simple or combined additions of cement was proved fragile for flexible structures, while those mixtures with simple emulsion addition had a better performance. We can imply that, for flexible pavements, the most appropriate choice is the mixture with addition of emulsion, while, in inverted pavements, the best choices are the mixtures with addition of cement and those combined with emulsion and cement. All the mixtures with additions showed an advantage in the structural equivalent and, consequently, in a smaller structure, turning the recycling of flexible pavements with addition of stabilizer agents an environmental alternative, technically and economically viable. It was also concluded that the use of a software to verify the fatigue compatible to the flexible, semirigid and inverted pavements would be ideal for this kind of job