| Popis: |
Engineered Cementitious Composite (ECC) is a new material composed of fine aggregates, cement and fibers, presenting high ductility associated with the ability to generate micro cracks when loaded (strain-hardening behavior). Research previously developed in the Federal University of Rio Grande do Sul (UFRGS) aimed at characterizing an ECC adapted to Brazilian materials, adding polypropylene fibers, and partially replacing cement by rice-husk ash. The research here reported was divided in two approaches. The first one consisted in the characterization of the mechanical properties of the ECC by laboratory tests of flexural behavior and compressive strength, as well as the evaluation of adhesion and workability and 4-point fatigue tests. The second approach consisted in accelerated pavement tests with the linear traffic simulator of UFRGS Pavement Laboratory. Two overlays (50 and 30 mm thick) were built over asphalt pavements presenting the same cracking pattern. On each overlay, 100,000 cycles of the 11 tons axle-load were applied. The appearance and evolution of cracks and other distresses were monitored, as well as surface wear. After APT, plates were sawn and it was noticed that the appearance of cracks is associated to the strong adherence in the interface between the two layers, and in a lesser degree to reflective cracking. Besides, it was concluded that quality control is mandatory to assure the composite performance. Overall, it has been found out that the ECC can be applied in the rehabilitation of pavements. |
