Micro surfacing (MS) is a type of bituminous coating frequently applied in the surface of pavement structures in order to prevent the occurrence of common distress and/or as a maintenance procedure. Micro surfacing has successfully been used in some states of Brazil as well as in many countries all over the world. Local aggregates used for micro surfacing composition are in some cases scarce and/or expensive. Therefore, the main objective of the present research is to verify the technical, financial and environmental viability of using steel slag aggregate (SSA) in micro surfacing applications. To reach the main objective, a procedure was developed in four steps. In the first step it was made the characterization of conventional (granitic) and alternative aggregates (steel slag) and polymer-modified emulsified asphalt. In the second step, mix design, surface abrasion resistance and setting time tests were performed. In the third step, the micro surfacing mechanical performance was analyzed using a laboratory traffic simulator to observe accumulated permanent deformation; surface wear; micro texture and macro texture. In the fourth step, a comparative study of costs concerning micro surfacing application using conventional mineral aggregate (MS-MA) and alternative aggregates (MS-SSA) were performed. The laboratory procedure results indicated that the steel slag studied has the potential to be used in micro surfacing applications with more rutting resistance and better durability. The cost analysis showed for medium transport distances bigger than 60 km, the MS-SSA will be cheaper than MS-MA solution.

This work investigates the potential of penetration, in terms of bituminous prime coat, of an asphalt mixture produced adding Soy Biodiesel [BIO] to the Asphalt Cement [AC] to be used in low traffic volume roads in the state of Ceara, Brazil. The main objective of this investigation was finding a less polluting alternative, by replacing kerosene, usually applied as diluent of AC in the traditional mixture CM-30. Therefore, a comparative study was made between the traditional binder [CM-30] and the proposed mixture [40% of Soy Biodiesel and 60% of AC 50/70], named as AC/BIO. Both tested binders were used in specimens made by the stabilization of a sandy soil, adding 50% and 60% of construction and demolition waste, resulting in two different soil-aggregate mixtures. The research considered some factors that influence the extent of penetration of the prime coat: moisture content of the base, type and volume of binder used and compaction energy. The characterization of the materials used in this research included tests such as the gradation of the aggregates, CBR and Resilient Modulus of the mixtures soil/aggregate, viscosity Saybolt-Furol and penetration of the binders (traditional and AC/BIO) in the samples of soil/aggregate. The results showed that the penetration potential of the AC/BIO mixture was similar to the CM-30 keeping the technical viability.