Impact of Petrography and Hardness of Sandstone Minerals on the Wear of Mini Disk Cutters through Rolling Indentation Abrasion Test (RIAT)

Abrasivity is one of the most important properties in drilling and tunneling projects. This phenomenon, which increases costs and significantly reduces drilling efficiency, is quantified using various techniques. The Cerchar test (CAI) and the Rolling Indentation Abrasion Test (RIAT) are, respectively, one of the oldest and newest methods in this regard. In this new test, the weight loss (RIATa) and depth of penetration of the mini disc cutters into the sample (RIATi) are measured. In the present research, 18 sandstone samples were prepared and their petrography analysis were carried out as quartz percentage (Q%) and equivalent quartz content (EQC). Moreover, Cerchar abrasion index (CAI) for each sample was determined by the Cerchar test. Finally, the RIAT test was performed on the samples to determine their abrasion penetration rate (APR = RIATa/RIATi) and penetration time rate (PTR = RIATi/Time) as two new abrasion criteria. The results showed that there is an inverse significant relationship between APR and PTR. In addition, there was a significant and direct relationship between APR and Q%, APR and EQC, and APR and CAI. The quadratic and exponential models were identified as the most valid models. Overall, the relationship between PTR and Q%, PTR and EQC, and PTR and CAI is inverse, and exponential and inverse models are the most valid models. The results showed that Q%, EQC, and CAI can be considered for evaluating the disc cutters wear in the laboratory model. A comparison of the results of the present and previous study showed that the variations of APR–EQC, APR–CAI, PTR–EQC, and PTR–CAI were similar. The minor difference between the present and previous results is due to the mineralogical differences.