Avaliação dos tratamentos superficiais simples, duplo e triplo de rodovias através do emprego de diferentes agregados da região metropolitana de Fortaleza

Abstract

Asphalt Surface Treatment (AST) is a coating with small thickness and low cost, composed by spreading bituminous binder and mineral aggregate and subsequent compaction. AST can be utilized as the surface course of roads and/or in services of maintenance and conservation of highways, representing approximately 63% of Ceará state’s paved road. Despite its high utilization, nowadays there is not a laboratory design process to verify the performance, and to determine the better aggregates and bituminous binder rates. In practice, the AST design process follows the recommended rates by technical standards or by the experience of engineers. This MSc Thesis developed a laboratory design method and investigated the performance of AST for different mineral aggregates of the Fortaleza Metropolitan Area, for the cases of Simple Surface Treatment (SST), Double Surface Treatment (DST) e Triple Surface Treatment (TST). The AST coatings were evaluated using the mass loss suffered by specimens submitted to the Wet Track Abrasion Test (WTAT) and plates of soil-gravel submitted to the laboratory traffic simulator. RR-2C emulsion and emulsion modified by polymer known as RR2C-E were used as asphalt binders. The mineral aggregates used were from two quarriy near Fortaleza. A third aggregate investigated was the steel slag, a waste of steel production. The results showed that the plaids presented satisfactory mass loss. Through the WTAT no improvement was noticed in the performance of the coatings that utilized RR2C-E. The DST samples, submitted to the laboratory traffic simulator, presented better results for the aggregate 1 (gneiss) using the RR2C-E and the steel slag with conventional emulsion. It was concluded that the method developed for laboratory design, combined with the use of the laboratory traffic simulator, can be a tool to determinate the best aggregates and bituminous binder rates, as well as to evaluate different aggregates and bituminous binders to use in AST coatings.