Y. Zhang
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2 records found
1
A preventive maintenance strategy of spraying rejuvenators on asphalt pavement surfaces is being considered as a cost-effective and environmentally sustainable option to extend the service life of existing asphalt concrete pavements. Rejuvenators might penetrate into the asphalt concrete and soften (rejuvenate) the bituminous binder. In this paper, the rejuvenation effectiveness of two rejuvenators on an artificially aged mortar is assessed. Cylindrical mortar specimens were prepared from the artificially aged mortar and then treated by the rejuvenators. The rheological and shear fatigue properties of the reference and treated mortar specimens were measured using dynamic shear tests. Meantime, a three-dimensional column model was created to investigate the dynamic shear test's capability of detecting the rheological properties of a composite column with a soft material in its outer part and a stiff material in its inner part. From finite-element modeling, it is found that the shear modulus of the composite column is higher than that of the soft material and lower than that of the stiff material. However, the results of the dynamic shear tests show that the two rejuvenators did not decrease the complex shear modulus of the artificially aged mortar. In addition, the two rejuvenators did not change the shear fatigue life of the artificially aged mortar.
Porous asphalt concrete is widely used as a surfacing layer on highways in the Netherlands because of its benefit that it is effective in reducing traffic noise. However, the service life of porous asphalt wearing courses is limited due to the fact that it is vulnerable to raveling. A preventive maintenance strategy using surface treatment material is being considered as a cost-effective and environmentally sustainable option to extend the service life of existing porous asphalt wearing courses. In this paper, the effect of a surface treatment to porous asphalt wearing courses is discussed. A surface treatment material was sprayed on the porous asphalt pavement surfaces in two field trials. Computed Tomography (CT) scans were performed on the porous asphalt concrete cores from the field trials to measure their volumetric properties. The rotating surface abrasion tests were used to determine the raveling resistance of the porous asphalt concrete samples. Finite element models with a realistic structure of the porous asphalt concrete were created for analyzing the stresses and strains as a result of traffic loads in the pavement surface with the surface treatment material. It is found that the effect of the surface treatment is positive.