Study of the mechanical properties of the granitoid rocks and the influence of blasting parameters on the quality of aggregates : Literature Research

In order to carry out blasting operation with optimal results the influence of rock properties on fragmentation process and the quality of the aggregates should be studied with the proper thoroughness. Recent investigations of granitoid rocks infer that the resistance of rock to abrasion improves with increasing amount of quartz and feldspar. The increasing amount of mica results in the opposite effect. The resistance of granite to the impact effects improves with the increasing amount of mica and decreasing content of feldspar. Another finding states that flakiness positively influenced by the frequency of micro cracks, on the other hand, the increasing micro cracks frequency negatively affects on the rock strength. For practical reasons it can be concluded that safety blasting decreases the propagation of micro cracks, hence improves the quality of the rock material. To obtain desired quality of aggregates the blasting parameters and the types of explosives should be properly considered. This thesis work presents the review of the modern literature concerning the blasting operations and aggregates production. It combines both theoretical and practical parts. It describes the petrographical and mechanical properties of the granitoid rocks, different laboratory tests for mechanical properties and results, types and features of explosives, the parameters that intervene in blast designing and influence of blasting on rock aggregates. The rock mass properties greatly affect the blasting results and the quality of aggregates. However, it’s hard to extend this conclusion on full-scale blasting operations in mines and quarries, because the nature and properties of the rock mass change significantly over the short distances.Validerat; 20101217 (root)