Effect of gradation, compaction and water content on crushed waste rocks strength

Abstract

We reduced the size of the abstract to 170 words, but we cannot go lower without loosing meaning. We hope it will be ok like this --> Open-pit mining operations generate large volumes of waste rocks. It can be both economically and environmentally attractive to valorise waste rocks in mining infrastructures such as haul roads. However current practice usually consists of using waste rock directly, without any preparation or selection, thus frequently resulting in punctures, dust generation and low durability. The aim of this study was therefore to determine optimal geotechnical properties of crushed waste rocks for use in surface course layer. Crushed waste rocks were characterised in the laboratory. Their strength was evaluated using California Bearing Ratio (CBR) tests. Several compaction energies were used, and he effect of maximum particle size, fines content, and dry density on the strength were assessed. Results showed that these parameters had a significant impact on the performance of the material. The strength was maximum for an optimum FC of around 10%, a high density and in the presence of coarser particles. Two regression models were also proposed to predict the CBR value of crushed waste rocks based on their physical properties.