Influence of curing time on impact energy absorption characteristics of artificially cemented sand

Abstract

To investigate the influence of curing time on impact energy absorption characteristics of artificially cemented sand in geomechanical model experiments, aluminium split Hopkinson pressure bar apparatus with bar diameter of 37 mm has been developed to conduct impact uniaxial compression tests under various striker velocities. The curing times of artificially cemented sand are 7 days, 14 days, and 21 days, respectively. Then test results have been analyzed from the energy point of view. Test results show that only a small amount of energy goes through the specimen and passes into transmitted bar in impact uniaxial compression tests, while most of incident energy is reflected back to incident bar for relatively low wave impedance of artificially cemented sand. With striker velocity increasing, there is an obviously positive linear relation between specific energy absorption (SEA) of artificially cemented sand specimens and squared striker velocity. As the bonding, mechanical behaviors between sand particles are gradually strengthened with curing time growing, the impact energy absorption characteristics of artificially cemented sand increases with curing time growing under certain striker velocity condition. And the increasing rate from 7 days to 14 days is slower, while it is faster from 14 days to 21 days. With respect to the SEA of artificially cemented sand cured 7 days, the impact energy absorption increase factor (IEAIF) of artificially cemented sands cured 14 days and 21 days are 1.19 and 1.48, respectively.