Buy article PDF
The purchased file will be sent to you
via email after the payment is completed.
US$ 35
|
Computers and Concrete Volume 33, Number 5, May 2024 (Special Issue) pages 605-619 DOI: https://doi.org/10.12989/cac.2024.33.5.605 |
|
|
|
Investigating meso-scale low-temperature fracture mechanisms of recycled asphalt concrete (RAC) via peridynamics |
||
Yuanjie Xiao, Ke Hou, Wenjun Hua, Zehan Shen, Yuliang Chen, Fanwei Meng and Zuen Zheng
|
||
| Abstract | ||
| The increase of reclaimed asphalt pavement (RAP) content in recycled asphalt concrete (RAC) is accompanied by the degradation of low-temperature cracking resistance, which has become an obstacle to the development of RAC. This paper aims to reveal the meso-scale mechanisms of the low-temperature fracture behavior of RAC and provide a theoretical basis for the economical recycling of RAP. For this purpose, micromechanical heterogeneous peridynamic model of RAC was established and validated by comparing three-point bending (TPB) test results against corresponding numerical simulation results of RAC with 50% RAP content. Furthermore, the models with different aggregate shapes (i.e., average aggregates circularity (Cr=1.00, 0.75, and 0.50) and RAP content (i.e., 0%, 15%, 30%, 50%, 75%, and 100%) were constructed to investigate the effect of aggregate shape and RAP content on the low-temperature cracking resistance. The results show that peridynamic models can accurately simulate the low-temperature fracture behavior of RAC, with only 2.9% and 13.9% differences from the TPB test in flexural strength and failure strain, respectively. On the meso-scale, the damage in the RAC is mainly controlled by horizontal tensile stress and the stress concentration appears in the interface transition zone (ITZ). Aggregate shape has a significant effect on the low-temperature fracture resistance, i.e., higher aggregate circularity leads to better low-temperature performance. The large number of microcracks generated during the damage evolution process for the peridynamic model with circular aggregates contributes to slowing down the fracture, whereas the severe stress concentration at the corners leads to the fracture of the aggregates with low circularity under lower stress levels. The effect of RAP content below 30% or above 50% is not significant, but a substantial reduction (16.9% in flexural strength and 16.4% in failure strain) is observed between the RAP content of 30% and 50%. This reduction is mainly attributed to the fact that the damage in the ITZ region transfers significantly to the aggregates, especially the RAP aggregates, when the RAP content ranges from 30% to 50%. | ||
| Key Words | ||
| low-temperature crack resistance; meso-scale model; peridynamics; reclaimed asphalt pavement; recycled asphalt concrete | ||
| Address | ||
| Yuanjie Xiao: 1) School of Civil Engineering, Central South University, Changsha 410075, China, 2) Ministry of Education Key Laboratory of Engineering Structures of Heavy Haul Railway (Central South University), Changsha 410075, China Ke Hou, Wenjun Hua and Zehan Shen: School of Civil Engineering, Central South University, Changsha 410075, China Fanwei Meng and Zuen Zheng: Hunan Communications Research Institute Co., Ltd., Changsha 410114, China | ||