[1]School of Resources and Safety Engineering, Central South University, Changsha 410083, China;
[2]Hunan Provincial Key Laboratory of Shale Gas Resource Utilization, Hunan University of Science and Technology, Xiangtan 411201, China;
[3]School of Highway, Chang’an University, Xi’an 710064, China;
water absorption ratio; Brazilian disc test; fracture surface; morphological analysis; roughness;