Experimental Research On Seismic Behavior Of Short Column With Ultra High Toughness Cementitious Composites

Ultra high toughness cementitious composites(Ultra High Toughness Cementitious Composites,referred UHTCC)is a new type of high performance fiber reinforced concrete,it continues to carry out in-depth research in recent years,the majority of researchers found that the material in the basic mechanical performance excellent,especially in the bending test showed significant damage when ductile characteristics and strain hardening characteristics,the paper presents a reference to the new ideas of this material short column,the purpose is to improve the traditional short columns in seismic shear environment cut brittle failure mode.By 5 using the new high toughness cementitious composites short column with a plain concrete short column of a test piece,were studied under low cyclic loading.The main research work and results are as follows:Research on the high toughness cementitious composites formulation techniques,and at different ages by 108 standard test block,were investigated its main mechanical(compressive,tensile,bending)performance indicators.The test results show that: with the rate of growth of fiber-containing almost no effect on the compressive strength of the specimen,and is conducive to enhance the tensile strength;in the bending test,not incorporated into the matrix material specimen surface fibers cracks after load-displacement curve declined rapidly and damage,showed typical brittle failure,and the incorporation of different fiber content of cement-based composite material specimen can continue to bear the load on the rear surface cracks,and accompanied by a number of fine cracks,revealing significant strain hardening phenomenon,presented is a good ductile failure phenomenon.High axial compression ratio,respectively 0.8 and 0.9 Overrun shaft under the pressure ratio of different fibers containing rate conditions,by applying a low cycle for new high toughness cementitious composites repeated short columns under cyclic loading,analysis in axial force,bending moment,shear the combined effects of short columns under the force of the energy dissipation capacity,stiffness and ductility coefficient of performance degradation,and with ordinary concrete columns with comparative advantages failure mode.Process and the results are as follows: The six short column failure process and analyze the reasons for the different results obtained high toughness cementitious composites loaded onto a short column of cracks from the yield,and always maintain steady crack,eventually occurs ductile failure.Combined with experimental data collection,drawing the hysteresis curves,skeleton curves and stiffness degradation curve short columns,on this basis,in-depth analysis of short columns ductility coefficient,energy dissipation capacity,research high toughness cementitious composites Short columns seismic performance.