Long-term abrasion of rocks assessed by micro-Deval tests and estimation of the abrasion process of rock types based on strength parameters

Testing long-term properties of aggregates requires time consuming laboratory tests. Alternatively, mathematical models can also be used to describe the abrasion process of aggregates. The paper uses another approach it links long-term abrasion to rock mechanical properties to facilitate a quick assessment of long term behavior of aggregates. It explores the long-term durability of aggregates through the application of long-term micro-Deval tests, extending the validity range of the relevant European standard (EN 1097-1:2012), that only requires 12,000 rotations for quality testing. Seven andesite lithotypes obtained from four Hungarian quarries were analyzed. The long-term micro-Deval coefficients were determined by increasing the number of rotations from the standardized 12,000 until the material loss reached the value of 99 m%. With some andesites, only 240,000 rotations were needed, while other ones required 2,000,000 rotations to a material loss of 80 m%. Regression analyses were used to find suitable models that describe the behaviour of the aggregates subjected to abrasion. The test results and the regression analyses supported previous studies suggesting that exponential functions are suitable to model abrasion. The abrasion model parameters introduced here were compared with the rock mechanical parameters of andesites and other lithotypes. It was found, that the newly introduced abrasion parameter A, which is a material-dependent empirical parameter, correlates with the ratio of the uniaxial compressive strength and water absorption. The introduction of the abrasion parameter provides an easy-to-use tool for the description of the behavior of aggregates exposed to natural or artificial abrasive effects. The knowledge of the abrasion process is essential for the lifetime analyses of crushed stones used as construction material or for the investigation of mass change of the grains in sedimentary systems such as riverbeds or coastal zones.

Automated summary

This paper explores the long-term durability of aggregates by linking long-term abrasion to rock mechanical properties. The introduction of a new abrasion parameter provides an easy-to-use tool for describing the behavior of aggregates exposed to natural or artificial abrasive effects. Regression analyses supported the use of exponential functions to model abrasion behavior, and found correlations between the new abrasion parameter and rock mechanical parameters.