Tatsunori SUZUKI
Study on quality evaluation method of asphalt concrete recycled aggregate in consideration of the viscoelasticity of the binder
Osamu Takahashi
In Japan, the performance of reclaimed pavement material is evaluated by hardness of asphalt using penetration test. For recycling, it had to be over 20 penetration value. However, in recent years, the demand of modified asphalt which is low penetration is on the rise. It is difficult to evaluate correctly the properties of old asphalt with only penetration. Therefore, the standard value which uses splitting coefficients in addition to the penetration is defined on the hosou-saisei-Handbook 2010. In case the penetration of the old asphalt is more than 20(1/10mm) or splitting coefficients is less than 1.70MPa/mm, we can use the asphalt concrete recycled aggregate.
In previous studies, we evaluated the properties of the binder by using FD value from the Force-Ductility-Test. As a result, there is a high correlation to the fatigue fracture resistance of the asphalt mixture and FD value, and we can evaluate the physical properties of the asphalt mixture indirectly from the binder properties. And, the FD values require more than 800Nmm was proposed as the standard value that is in order to produce the recycled mixture that has the fatigue fracture resistance of the straight asphalt.
However, it is necessary to verify whether there is a correlation in FD value and splitting coefficient due to not considering the evaluation using splitting coefficient. In this study, in order to establish a new evaluation test in quality control of asphalt concrete recycled aggregate, we compared splitting coefficient that was obtained from splitting test and the results of FDT. The following findings were obtained.
It was not possible to confirm the correlation value FD and splitting coefficients. However, from the relationship of Deformation Resistance values and splitting factor, regardless of the degradation state and binder species, correlation is established could be confirmed. In addition, DR value corresponding to the splitting coefficient 1.70MPa/mm was found to take the 1100Nmm approximately. In introducing FDT, FD values of the old asphalt in the value of more than 800N mm and DR value is less than 1100Nmm, it is assumed that can be used asĦĦasphalt concrete recycled aggregate.
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