Estudo de concreto asfáltico permeável com asfalto polímero e adição de fibras de celulose

Abstract

The American Environmental Practices Agency (EPA, 2009), within the proposal of sustainable practices, suggests the replacement of waterproof coatings for others such as permeable asphalt concrete. The use of this coating allows reduction on water accumulation, increased grip, increased traffic safety in wet road conditions and reduced rolling noise. The present work aimed to study the influence of the addition of four different contents of cellulose fiber in a mix of permeable asphalt concrete with polymer modified binder. Aggregates of the particle size range I of the Porous Friction Layer standard (DNER-ES 386/99) were used. The design binder content was 4%, corresponding to 18.3% voids. Using 0%, 0.25%, 0.50% and 0.75% of fibers, five parameters were analyzed: permeability coefficient (adaptation of the method prescribed in the ACI 522R – 06); content of communicating voids (AFNOR-NF-P-98-254-2 - 1993); loss to cantabrian (DNER-ME 383/99); tensile strength by diametrical compression (DNIT 136/2018 - ME) and resilience modulus (DNIT 135/2018-ME). In the absence of a standard that regulates the permeability coefficient measurement process, an equipment capable of testing compacted CPs according to DNER-ES 386/99 was created. The apparatus, inspired by an american standard, proved to be efficient; the methodology constitutes a possibility of complement of the porous friction layer standard. The parameters on which the fiber percentage exerted a significant influence were Resilience Modulus (MR) and Permeability Coefficient (k). The MR value was maximum when the fiber content was 0.25%, similar to the obtained for the 0% group and significantly different from the 0.50% and 0.75% groups. The k value was significantly different for each group, showing an increase up to the addition of fibers by 0.50%. The group with 0.50% fiber had the highest value of k and MR 32% lower than the group with 0.25%. When compared to the groups without fiber and with a content of 0.75%, the group with 0.25% presented the highest values of MR and k.