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Abstract To study compaction characteristics of crushed stones，the compaction tests on sandstone，mudstone and sandy mudstone from coal seam roof of Yima Xin?an mine were conducted by using RMT–150B servo machine. Stress-strain relation of crushed stones is obtained and the effects of rock strength，particle size and compaction stress on compression characteristics are analyzed. The results show that three stages are included by the following order during compaction process：rapid compression deformation stage，slow compaction deformation stage and stable compaction stage. The bulking factor increased with the increase of particle size by the logarithmic relationship. The difference of residual bulking factor after crushed stones experienced close and filling of interstice decreased，which has less to do with rock strength and particle size. The decrease amplitude of bulking factor augmented with the increase of lumpiness. The compactness of crushed stones is a function of compaction stress and the bigger the lumpiness was，the more obvious the change of compactness was. The higher the rock strength is，the greater the energy consumption is；and the average energy consumption ratio of sandstone，sandy mudstone and mudstone is 3.5∶2.2∶1.0. If the particle size of same stone is larger than 5 mm，the energy consumption is not relevant to the particle size.
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Received: 03 July 2011
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2012, Vol. 31 
