Abstract:The dynamic mechanical behaviors of cement mortar under quasi2one and one2dimensional st rain states are studied by using an improved passive confining SHPB method and one stage gas gun respectively. The f riction2 corrected dynamic elastic constant s and the yield st rength are calculated. And the shock adiabatics at intense dy2 namic loading by taking into account the internal damage is obtained. Furthermore the st ress2st rain curves of ce2 ment mortar under three different st ress states and the initial behavior of hydrodynamic curve are compared and an2 alyzed. It is shown that the result s obtained f rom the test s with confined pressure are quite different f rom the re2 sult s obtained f rom the gas gun test s , so that a quasi2one dimensional st rain test with confined pressure should not be approximately dealt with as an one dimensional st rain test .