Desenvolvimento de um método expedito para avaliação da imprimação betuminosa de rodovias

Abstract

Bituminous prime coat is the result of the application of binder on the base layer of a pavement in order to promote greater adherence to the surface. In Brasil, it is traditionally used CM-30 during the prime coat, but this material has kerosene as diluent of the Petroleum Asphalt Cement (CAP). In developed countries there is a major constraint on the use of the CM-30 primer. This restriction occurs because it is considered polluting to the environment due to proper handling of bituminous material, as well as the emission of Volatile Organic Hydrocarbons (VOC's). There are few published studies on bituminous primer, in Brazil and in the world highlighting the need to develop studies on the performance of alternative ligands that may in the future replace the CM-30. In Brazil, the selection of new binders in the laboratory to verify the penetration of bituminous priming, involves an exhaustive preparation of the Samples (CPs) which is very time consuming. For every variable to be tested (binder type and rate, soil type, compaction, irrigation rate prior, etc.) are shaped at least three CPs for every moisture content, compacted using miniature cylinders (50 × 50) or modified Marshall (100 × 50). This paper proposes a methodology for expeditious evaluation of priming alternative binders to reduce the time and amount of sample. Therefore, test samples were molded in capsules 43mm in diameter and 22mm in height in a sample of sandy soil, using the conventional binder type CM-30. The molding was performed using a coesimetro for compaction the soil in the capsule. It was found that the proposed method can be a simple, fast and inexpensive evaluation of the penetration of bituminous priming and can contribute to the previous selection of alternative binders.