3D　concrete　printing　is　an　innovative　and　promising　construction　method　that　is　rapidly　gaining　ground　in　recent　years.　This　technique　extrudes　premixed　concrete　materials　through　a　nozzle　to　build　structural　components　layer　upon　layer　without　formworks.　The　build-up　process　of　depositing　filaments　or　layers　intrinsically　produce　laminated　structures　and　create　weak　joints　between　adjacent　layers.　It　is　of　great　significance　to　clearly　elaborate　the　mechanical　characteristics　of　3D　printed　components　response　to　various　applied　loads　and　the　different　performance　from　the　mould-cast　ones.　In　this　study,　a　self-developed　3D　printing　system　was　invented　and　applied　to　fabricate　concrete　samples.　Three　points　bending　test　and　direct　double　shear　test　were　carried　out　to　investigate　the　mechanical　properties　of　3D　printed　prisms.　The　anisotropic　behaviors　were　probed　by　loading　in　different　directions.　Meanwhile,　piezoelectric　lead　zirconate　titanate　(PZT)　transducers　were　implemented　to　monitor　the　damage　evolution　of　the　printed　samples　in　the　loading　process　based　on　the　electromechanical　impedance　method.　Test　results　demonstrate　that　the　tensile　stresses　perpendicular　to　the　weaken　interfaces　formed　between　filaments　were　prone　to　induce　cracks　than　those　parallel　to　the　interfaces.　The　damages　of　concrete　materials　resulted　in　the　decrease　in　the　frequency　and　a　change　in　the　amplitude　in　the　conductance　spectrum　acquired　by　mounted　PZT　patches.　The　admittance　signatures　showed　a　clear　gradation　of　the　examined　damage　levels　of　printed　prisms　exposed　to　applied　loadings.